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%0 Report %D 2019 %T Accelerating the Deployment of Advanced Energy Communities: The Oakland EcoBlock A Zero Net Energy, Low Water Use Retrofit Neighborhood Demonstration Project %A Zach Barr %A Norman Bourassa %A John Bowie %A Richard E. Brown %A Nora DeCuir %A H. Jordan Diamond %A Amy Dryden %A Ethan Elkind %A Harrison Fraker %A Wenjie Fu %A Ethan Guy %A Daniel Hamilton %A Ted Lamm %A Maika Nicholson %A Leo Rainer %A Sandy Robertson %A Christine Scott Thomson %A Emma Tome %A Andréa Traber %K air-sealing %K Building energy simulation %K cfd %K city block %K community acceptance %K community energy %K community facilities district %K community-scale %K decarbonization codes %K demand response %K direct current %K Distributed energy resources %K duct sealing %K EcoBlock %K EcoDistrict %K efficiency %K energy efficiency %K energy savings %K energy storage %K equity innovation %K existing residential %K flywheel %K governance %K green bonds %K heat pump water heater %K HPWH %K innovative codes %K innovative governance %K joint powers authority %K JPA %K Mello-Roos %K Microgrid %K microgrid permitting %K outreach %K PACE %K photovoltaic %K planning %K property assessed clean energy %K public financing %K pv %K rainwater %K real estate data energy audit %K residential %K retrofit %K Smart ventilation %K stakeholder engagement %K stormwater %K utility API %K ventilation %K wastewater %X
This report describes the design development process and recommendations of a Community-Scale Zero Net Energy Master Plan for a residential block in Oakland, the Oakland EcoBlock. The recommended master plan includes an integrated system of energy efficiency retrofits, a direct current solar/storage/electric vehicle microgrid, alternating/direct current houses, and water efficiency retrofits with rainwater capture. The recommended master plan is projected to be close to zero-net energy (95 percent) for homes, reduce carbon emissions by 65 percent at the block scale (including transportation), and reduce water use 60–70 percent.
The integrated system of energy efficiency and a direct current solar/storage/electric vehicle (EV) charging microgrid is the first of its kind at the residential block scale. This breakthrough because the deep energy efficiency retrofit savings free up enough capacity in the solar supply and storage to enable residents to switch from natural gas to electricity for heating and domestic hot water and to provide EV charging for 33 percent of vehicle miles traveled. The savings in household transportation costs are a game changer because when combined with savings in the electric and water utility bills, the total cash flow savings are projected to fund the capital improvements of the proposed systems.
This project's benefits include lower and more predictable utility bills; greater resiliency because the system can operate during outages, and vastly improved indoor air quality by reducing natural gas consumption. The local energy storage reduces peak demand for the utility. California benefits from a model that exceeds the targets for reductions in energy consumption and carbon emissions and the reductions in water use address California's severe water challenges.
The Oakland EcoBlock is a transformative model for accelerating the rapid deployment of advanced energy communities.%8 04/2019 %G eng %U https://oapolicy.universityofcalifornia.edu/viewobject.html?cid=1&id=2751950 %0 Journal Article %J Joule %D 2019 %T Assessing the Potential to Reduce U.S. Building CO2 Emissions 80% by 2050 %A Jared Langevin %A Chioke B. Harris %A Janet L. Reyna %K Building energy efficiency %K decarbonization %K electrification %K emissions %K energy models %K energy policy analysis %K national climate goals %K pathways building stock %X
Buildings are responsible for 36% of CO2 emissions in the United States and will thus be integral to climate change mitigation; yet, no studies have comprehensively assessed the potential long-term CO2 emissions reductions from the U.S. buildings sector against national goals in a way that can be regularly updated in the future. We use Scout, a reproducible and granular model of U.S. building energy use, to investigate the potential for the U.S. buildings sector to reduce CO2 emissions 80% by 2050, consistent with the U.S. Mid-Century Strategy. We find that a combination of aggressive efficiency measures, electrification, and high renewable energy penetration can reduce CO2 emissions by 72%–78% relative to 2005 levels, just short of the target. Results are sufficiently disaggregated by technology and end use to inform targeted building energy policy approaches and establish a foundation for continual reassessment of technology development pathways that drive significant long-term emissions reductions.%B Joule %8 08/2019 %G eng %R 10.1016/j.joule.2019.07.013 %0 Report %D 2019 %T Efficient and Zero Net Energy-Ready Plug Loads %A Alan K. Meier %A Richard E. Brown %A Daniel L. Gerber %A Aditya Khandekar %A Margarita Kloss %A Hidemitsu Koyanagi %A Richard Liou %A Leo I. Rainer %A Seth Sanders %K alarm %K burst mode %K circuit %K commercial buildings %K CPAP %K dc power %K energy harvesting %K GFCI %K hardwired %K health %K MELs %K miscellaneous electrical loads %K networks %K oxygen concentrator %K Plug loads %K residential buildings %K safety %K standby power %K wake-up radio %X
Plug loads are the devices plugged into common electrical outlets. Modern buildings contain hundreds of these devices which, together, are responsible for at least 25 percent of the energy use in California buildings. Energy consumed by plug loads is increasing because the "Internet of Things" is, to a great extent, the "Internet of Plug Loads." This project developed technologies that will reduce the energy use of plug loads. Two crosscutting strategies were investigated in detail: (1) technologies to reduce standby power use to near zero, and (2) methods to increase the use of direct current (DC) as a power source. Two new approaches to reduce standby to near zero were developed and have potential applicability to a wide range of devices. Prototype DC appliances were developed to demonstrate energy savings by bypassing power supplies and avoiding other losses. Networks of DC-powered devices can save even more energy and provide other benefits, such as resiliency during power outages. A unique category of energy-using devices was identified that provide life safety, health, and security to building occupants. Their installation or use is dictated by building codes, health providers, insurance companies, and other entities—none of whom would ordinarily prioritize energy efficiency. In the case of ground fault circuit interrupts (GFCIs), savings of 80 percent appear possible, simply by adopting the most efficient designs. Home medical equipment, particularly oxygen concentrators, are a rising category of energy use where significant savings are possible. This report also reviews the codes, standards, and other policies that affect energy use of plug loads.%G eng %0 Report %D 2019 %T Energy Efficiency and the Real Estate Lifecycle: Stakeholder Perspectives %A Paul A. Mathew %A Philip Coleman %A Janie Page %A Cynthia Regnier %A Jordan Shackelford %A Greg Hopkins %A Matt Jungclaus %A Victor Olgyay %8 07/2019 %G eng %2 LBNL 2001214 %0 Report %D 2019 %T Energy Modeling in Urban Districts: Forecast of multi-sector Energy Use and GHG Emissions %A Reshma Singh %A Baptiste Ravache %A Mary Ann Piette %K buildings %K developer %K District-scale %K Electric Mobility %K energy %K forecast %K ghg emissions %K land use planning %K models %K pv %K Renewables %K Smart Cities %K urbanization %K visualization %X
This document reports the findings of the energy use and greenhouse gases (GHG) emissions model loosely based on three districts in the Bay Area, District A, District B, and District C.
Modeling platforms exist for city energy benchmarking, inventorying, and GHG emissions forecasting and planning. However, the wide variety and features of today's tools, their focus on a sub-set or snapshot data from various energy generation and consumption sectors, and the fact that many of them are not open data models, create sub-optimal environments for the energy analysis districts are seeking to conduct. Hence, we have developed a new software tool with customized data and dynamic visualization; DEPICT (Decision-support and Emissions Prediction Interactive Cities Tool) to obtain energy and emissions forecasts at different stages of the districts' build-out by varying selected design parameters. This report presents the methodology and framework we have developed to estimate whole district emissions and details the results by district, with the objective of finding insights into the main sources of emissions, and the available levers to reduce them efficiently. This document details the impact of each emissions mitigation measure investigated, along with the assumption and models that were used to reach these values. The key findings for each district are presented in Table 1 and Table 2.
In this work we present a methodology to evaluate the accuracy of methods used to quantify the uncertainty in estimated total energy savings. We focus on savings measurement and verification (M&V) approaches that use a baseline model to characterize energy use, and that forward-project the model for a counterfactual to determine avoided energy use. These approaches are common to the International Performance Measurement and Verification Protocol's (IPMVP's) Option C and Option B. This methodology can be used to evaluate the uncertainty in savings estimates that are due to model error. It has been applied to evaluate two uncertainty estimation methods, including the industry standard ASHRAE Guideline 14 approach. The evaluation used data from 69 commercial buildings and four different baseline models that span daily and hourly granularity, as well as linear and non-linear/non-parametric forms. The findings of this work indicate that the standard methods that are widely used by the M&V community for estimating the total savings uncertainty over the post-installation period tend to underestimate the uncertainty. The tendency to underestimate the uncertainty is stronger for hourly models than for daily models, due to stronger autocorrelation in model residuals at the hourly time scale.%B Energy and Buildings %V 193 %8 06/2019 %G eng %R https://doi.org/10.1016/j.enbuild.2019.03.041 %0 Journal Article %J Environmental Science & Technology %D 2019 %T Evaluation of U.S. Manufacturing Subsectors at Risk of Physical Water Shortages %A Prakash Rao %A Darren Sholes %A Joe Cresko %K manufacturing %K Risk %K water %X
The potential impact of water shortages on U.S. manufacturing is unknown. While water for manufacturing constitutes an estimated 6% of U.S. water intake, the data (i.e., location, quantity, and purpose of water intake) needed to determine this impact does not exist. This paper will identify manufacturing subsectors at risk of physical water shortages by applying a method for estimating U.S. manufacturing water intake at the necessary spatial and sectoral resolutions. First, the data requirements to quantify a manufacturing facility's water footprint within the context of the watershed are developed. Second, using international data, water intake at the national, state, and county-levels by each U.S. manufacturing subsector is estimated. Third, manufacturing subsectors that are most vulnerable to risks of physical water shortages are identified. Based on the results, the Paper, Primary Metals, Chemical, Petroleum and Coal Products, and Food subsectors have the largest intake, respectively. However, the Primary Metals, Fabricated Metals, Transportation Equipment, Petroleum and Coal Products, and Plastics and Rubber subsectors are at the greatest risk of physical water shortages based on concentrations of water intake in water-stressed regions. The results can be used to develop strategies to mitigate the risks of water shortages on the U.S. manufacturing sector%B Environmental Science & Technology %8 2/2019 %G eng %U http://pubs.acs.org/doi/10.1021/acs.est.8b04896http://pubs.acs.org/doi/pdf/10.1021/acs.est.8b04896 %! Environ. Sci. Technol. %R 10.1021/acs.est.8b04896 %0 Report %D 2019 %T Heat Island Mitigation Assessment and Policy Development for the Kansas City Region %A Haley E. Gilbert %A Tom Jacobs %A Seongeun Jeong %A Melvin Pomerantz %A Dev Millstein %A Doug Norsby %A Andrea Repinsky %A Ronnen M. Levinson %K building energy savings %K cool roofs %K Kansas City %K simple payback %K urban climate %K Urban heat islands %K vegetation %X
Lawrence Berkeley National Laboratory partnered with Mid-America Regional Council (MARC) to quantify the costs and benefits from the adoption of urban heat island (UHI) countermeasures in the Kansas City region (population 1.5 million), and identify the best regional implementation pathway for MARC. The team selected cool (high-albedo) roofs and increased vegetation as the two countermeasures to evaluate. For vegetation, there were two strategies: (1) planting new trees to shade building surfaces, and (2) increasing urban irrigation (a surrogate for the use of vegetation to manage stormwater) to increase evapotranspiration. Using the Weather Research and Forecasting (WRF) model we simulated selected weeks during summer time, across five years (2011 – 2015) representing a range of normal summer conditions. We also simulated six of the most intense heatwaves that occurred between 2004 and 2016. We found under typical summer conditions (non-heatwave) average daytime (07:00 – 19:00 local standard time) regional near-ground air temperature reductions of 0.08 and 0.28 °C for cool roofs and urban irrigation, respectively. We calculated the building electricity, electricity cost, and emission savings that result from the reduction in outdoor air temperature ("indirect" savings) and found maximum regional annual indirect electricity savings of 42.8 GWh for cool roofs and 85.6 GWh for urban irrigation—yielding maximum regional annual indirect electricity cost savings of $5.6M ($0.05/m2roof) and $11.1M ($0.01/m2 irrigated land), respectively, and maximum regional annual CO2 savings of 43.4 kt and 80 kt, respectively.
We next evaluated the building energy, energy cost, and emission savings from reducing direct absorbed radiation on the building surfaces using cool roofs and shade trees ("direct" savings). For cool roofs, we found regional annual direct energy cost savings of $10.9M ($0.15/m2 roof) with regional annual CO2 savings of 66.4 kt. For shade trees, the regional annual direct energy cost savings were $21M ($21/tree) with regional annual CO2 savings of 126 kt. We investigated cool roof cost premiums (the additional cost for selecting a cool roof product in lieu of a conventional roof product, estimated to be zero to $2.15/m2) and shade tree first costs (assumed to be $100 per tree). The regional cool roof cost premium was calculated using the regional roof area per roofing material type and the range of cool roof product premiums for each material type. The extra cost of selecting cool roofs across the region ranged from $4.33M to $87.1M, while the additional shade trees planted across the region were assumed to cost $102M. When we compared the regional annual direct cost savings to the regional cool-roof cost premium and the regional shade-tree first cost, we found regional simple payback times up to 8.0 years for cool roofs and 4.9 years for trees, respectively.
Since this comprehensive assessment of UHI countermeasures is a valuable methodology for other local governments to apply, we developed a step-by-step guide for others to follow. Based on the benefits and costs of the UHI countermeasures, MARC will pursue the inclusion of these countermeasures in existing regional plans where they can complement other regional priorities for transportation, climate resiliency, clean air, and hazard mitigation. They hosted a local workshop in 2016 for stakeholders to introduce the topic and will continue to share these resources to further appropriate adoption of UHI countermeasures.%8 10/2019 %G eng %R 10.20357/B7JG61 %0 Conference Proceedings %B 20th Congress of the International Ergonomics Association (IEA 2018) %D 2019 %T Local lighting control in open-plan offices: the influence of office lay-out %A Christel de Bakker %A Marielle Aarts %A Helianthe Kort %A Alan K. Meier %A Alexander Rosemann %X
Highly granular lighting control involves switching on and off luminaires based on individual occupancy. The resulting high frequency of lighting changes can distract the office workers and negatively impact their work performance. In a cubicle office, this might be less of an issue than in an office without partitions, as users do not have an overview over the space here. We tested this control strategy in both office types and compared the results to determine the influence of office lay-out on the amount and acceptability of distractions that it poses. Our results indicated the opposite: occupants in the cubicle office were more often distracted and rated the distractions as less acceptable than in the bullpen office. As the job function types varied and the bullpen was consequently more dynamic, it seems that the type of work environment is of larger influence on users' satisfaction with local lighting control. However, more research is required to confirm this finding.%B 20th Congress of the International Ergonomics Association (IEA 2018) %G eng %0 Report %D 2019 %T Monitoring the Urban Heat Island Effect and the Efficacy of Future Countermeasures %A Ronnen M. Levinson %A Howdy Goudey %A Sharon S. Chen %A Haley E. Gilbert %A George A. Ban-Weiss %A Joseph Ko %A Yun Li %A Arash Mohegh %A Angie Rodriguez %A Jonathan L. Slack %A Haider Taha %A Tianbo Tang %A Jiachen Zhang %K : Urban heat islands %K fine-scale meteorological model %K intra-urban temperature variability %K land-use and land-cover %K mobile transects %K personal weather stations %K stationary weather monitor %K urban cool islands %X
To relate fine-scale spatial air-temperature variations in local urban heat islands and urban cool islands—increases and decreases in outside air temperature—within a large urban-climate archipelago to variations in land-use and land-cover properties in the Los Angeles Basin, the research team sought to (a) use fine-resolution meso-urban climate models to identify areas of urban heat and cool islands, select sites for fixed weather monitoring, and choose routes for mobile observations; (b) relate observed intraurban temperature variations to land use and land cover and surface physical properties; and (c) calibrate/validate the climate models. The research team assessed urban temperature variations via simulations and observations, including mobile transects, mesonet, dense networks of personal weather stations, and sparse but more accurate research-grade monitors. To identify the causative factors of the urban heat and cool islands at the neighborhood scale, the research team collected detailed urban morphometric and land use and land cover datasets, such as 1-meter (3.3 foot) resolution roof albedo (solar reflectance) and tree canopy cover. The research team used the observationvalidated model to finalize the transect routes and site the stationary monitors.
This study provides the first observational evidence from analysis of high-spatial-density weather stations that increases in roof albedo at neighborhood scale are associated with reductions in near-surface air temperature. This finding was corroborated with the analysis from mobile transect measurements and correlation of observed air temperature with neighborhood-scale albedo and vegetation. This correlation revealed a cooling effect from areawide increase in albedo or canopy cover or both.
The calibrated meteorological model accurately identified the localized urban heat and cool islands observed in this study. Interested stakeholders/researchers can use the same models and calibration/validation methodology to characterize within-city microclimate variations elsewhere in California, and can apply them to analyze the benefits from using urban heat island countermeasures.
%8 03/2019
%G eng
%U https://www.energy.ca.gov/2019publications/CEC-500-2019-020/CEC-500-2019-020.pdf
%R https://doi.org/10.20357/B7DW2D
%0 Report
%T A Plug-Loads Game Changer: Computer Gaming Energy Efficiency without Performance Compromise
%A Evan Mills
%A Norman Bourassa
%A Leo I. Rainer
%A Jimmy Mai
%A Ian Vaino
%A Claire Curtin
%A Arman Shehabi
%A Louis-Benoit Desroches
%A Nathaniel Mills
%K computer gaming
%K data centers
%K energy efficiency
%K residential
%K virtual reality
This project report is an extended and more detailed version of a related report prepared for California's Fourth Climate Change Assessment.
Two-thirds of Americans play computer games. Although among the most complex and energyintensive plug loads, gaming has been largely overlooked in energy research and development and policy. Systems used for computer gaming in California consumed 4.1 terawatt-hours/year in 2016 or $700 million in energy bills, with emissions of 1.5 million tons carbon dioxideequivalent allocated 66 percent to consoles, 31 percent to desktop personal computers, 3 percent to laptops, and less than 1 percent to emerging media streaming devices. Key findings include:
• Aggregate energy demand places gaming among the top plug loads in California, with gaming representing one-fifth of the state's total miscellaneous residential energy use.
• Market structure changes could substantially affect statewide energy use; energy demand could rise by 114 percent by 2021 under intensified desktop gaming, or fall by 24 percent given a major shift towards consoles coupled with energy efficiency gains.
• Unit energy consumption is remarkably varied across gaming platform types: across 26 systems tested, client-side electricity use ranged from 5 to more than 1,200 kWh per year, reflecting equipment choice and usage patterns.
• Some emerging technologies and activities are driving energy demand higher, including processor overclocking, cloud-based gaming, higher-resolution connected displays, and virtual reality gaming.
• User behavior influences gaming energy use more than technology choice; duty cycle and game choice are particularly strong drivers of demand.
• Energy efficiency opportunities are substantial, about 50 percent on a per-system basis for personal computers and 40 percent for consoles if past rates of improvement continue.
While simultaneously quantifying efficiency and gaming performance is problematic, evidence suggests that efficiency can be improved while maintaining or improving user experience. Familiar energy policy strategies can help manage gaming energy demand, although mandatory system-level standards are not promising (component-level measures may be).%I CEC %8 04/2019 %G eng %0 Journal Article %J Applied Energy %D 2019 %T Practical factors of envelope model setup and their effects on the performance of model predictive control for building heating, ventilating, and air conditioning systems %A David Blum %A K. Arendt %A Lisa Rivalin %A Mary Ann Piette %A Michael Wetter %A C.T. Veje %K building simulation %K hvac %K Model predictive control %K System identification %X
Model predictive control (MPC) for buildings is attracting significant attention in research and industry due to its potential to address a number of challenges facing the building industry, including energy cost reduction, grid integration, and occupant connectivity. However, the strategy has not yet been implemented at any scale, largely due to the significant effort required to configure and calibrate the model used in the MPC controller. While many studies have focused on methods to expedite model configuration and improve model accuracy, few have studied the impact a wide range of factors have on the accuracy of the resulting model. In addition, few have continued on to analyze these factors' impact on MPC controller performance in terms of final operating costs. Therefore, this study first identifies the practical factors affecting model setup, specifically focusing on the thermal envelope. The seven that are identified are building design, model structure, model order, data set, data quality, identification algorithm and initial guesses, and software tool-chain. Then, through a large number of trials, it analyzes each factor's influence on model accuracy, focusing on grey-box models for a single zone building envelope. Finally, this study implements a subset of the models identified with these factor variations in heating, ventilating, and air conditioning MPC controllers, and tests them in simulation of a representative case that aims to optimally cool a single-zone building with time-varying electricity prices. It is found that a difference of up to 20% in cooling cost for the cases studied can occur between the best performing model and the worst performing model. The primary factors attributing to this were model structure and initial parameter guesses during parameter estimation of the model.%B Applied Energy %V 236 %P 410 - 425 %8 02/2019 %G eng %U https://linkinghub.elsevier.com/retrieve/pii/S0306261918318099https://api.elsevier.com/content/article/PII:S0306261918318099?httpAccept=text/xmlhttps://api.elsevier.com/content/article/PII:S0306261918318099?httpAccept=text/plain %! Applied Energy %R 10.1016/j.apenergy.2018.11.093 %0 Conference Paper %B IBPSA Building Simulation 2019 %D 2019 %T Prototyping the BOPTEST Framework for Simulation-Based Testing of Advanced Control Strategies in Buildings %A David Blum %A Filip Jorissen %A Sen Huang %A Yan Chen %A Javier Arroyo %A Kyle Benne %A Yanfei Li %A Valentin Gavan %A Lisa Rivalin %A Lieve Helsen %A Draguna Vrabie %A Michael Wetter %A Marina Sofos %K benchmarking %K building simulation %K Model predictive control %K software development %X
Advanced control strategies are becoming increasingly necessary in buildings in order to meet and balance requirements for energy efficiency, demand flexibility, and occupant comfort. Additional development and widespread adoption of emerging control strategies, however, ultimately require low implementation costs to reduce payback period and verified performance to gain control vendor, building owner, and operator trust. This is difficult in an already first-cost driven and risk-averse industry. Recent innovations in building simulation can significantly aid in meeting these requirements and spurring innovation at early stages of development by evaluating performance, comparing state-of-the-art to new strategies, providing installation experience, and testing controller implementations. This paper presents the development of a simulation framework consisting of test cases and software platform for the testing of advanced control strategies (BOPTEST - Building Optimization Performance Test). The objectives and requirements of the framework, components of a test case, and proposed software platform architecture are described, and the framework is demonstrated with a prototype implementation and example test case.%B IBPSA Building Simulation 2019 %C Rome, Italy %G eng %0 Report %D 2019 %T R&D and Implementation Outcomes From The U.S.-India Bilateral Center For Building Energy Research And Development Program %A Reshma Singh %A Mary Ann Piette %A Ashok J. Gadgil %A Rajan Rawal %A Narendra Bansal %A Vishal Garg %A Jyotirmay Mathur %A Philip Haves %A Paul A. Mathew %A Christian Kohler %A Mahabir Bhandari %A Gail Brager %A Vivian Loftness %A Narendran Nadarajah %A Ronnen M. Levinson %A Richard E. Brown %A Andre Desjarlais %A Milind Rane %A Sanyogita Manu %A Yash Shukla %A Mona Doctor-Pingel %X
This paper explores the role of international partnerships to facilitate low-energy building design, construction, and operations. We present the strategic approach, joint research and development outcomes, and implementation activities of a unique U.S.-India program on buildings energy efficiency, the Center for Building Energy Research and Development. We discuss the collaboration successes in both countries despite their dissimilar building contexts, implementation challenges and opportunities. We highlight a range of R&D outcomes, such as novel tools and technologies developed and tested by the joint teams, with their technical energy savings potential, as well as results of capacity building and technology demonstrations. A deep-dive into key new scientific methods around building energy monitoring and benchmarking that could have a significant impact on high-performance of buildings in both countries is also provided. Finally, in addition to joint R&D successes, pathways to deployment, and lessons learned are discussed as key takeaways.%8 08/2019 %G eng %R 10.20357/B74G69 %0 Report %D 2019 %T Sealed and Insulated Attic Hygrothermal Performance in New California Homes Using Vapor and Air Permeable Insulation—Field Study and Simulations %A Brennan Less %A Iain S. Walker %A Jonathan L. Slack %A Leo I. Rainer %A Ronnen M. Levinson %K air leakage %K Attic %K condensation %K Fiberglass %K heat %K hvac %K insulation %K moisture %K mold %K ventilation %K Wood Moisture Content %X
This project investigated the thermal and moisture performance of a low-cost approach to sealing and insulating attics using glass fiber insulation. The work included a combination of:
(1) field measurements of attic and HVAC system performance in two new, high performance homes in California's Central Valley (Fresno), and (2) hygrothermal simulations of attic performance. Each field study attic was continuously monitored at multiple locations for over a year for wood moisture content, air humidity, condensation, temperature, and heat flux, together with on-site weather and solar conditions. The Fresno test home showed periodic condensation and high surface wood moisture content, but no surface mold or degradation upon visual inspection at the end of the test period. The Clovis test home showed less indication of high moisture levels—either from surface condensation or wood moisture content—but did have visible suspected mold growth on the inside of the North sheathing at the end of the field testing. These results show the limitations of current moisture measurement techniques focused on wood moisture content, rather than potential for mold growth. From a thermal/energy perspective the attics were close to indoor conditions thereby realizing the design intent for reducing duct system losses. Simulated site HVAC energy savings for sealed vs. vented attics averaged 18% across California climate regions (8% TDV energy savings). Savings were dominated by heating energy reductions; cooling savings were substantially lower. The moisture issues are investigated in greater detail in the simulations. First, we identified the climate regions and house characteristics that are associated with increased risk of mold growth or wood rot in new CA homes. Climate region was very important in determining risk, as were house features that reduced outside air exchange (e.g., 1-story homes, very tight envelopes, very tight attics, no IAQ fan), along with those that increased flow of moist air from the living space to the attic (e.g., supply ventilation fans, larger ceiling leaks, duct leakage). Second, we investigated several approaches to reduce moisture risks, and the best approach was to use a vapor retarder on the inner face of the fiberglass insulation. Both the field and simulation results indicate that the use of air and vapor permeable insulation can be acceptable from a thermal/energy point of view, but additional measures need to be taken to reduce moisture risks, primarily from mold growth.
Raising the albedo (solar reflectance) of a building's walls reduces unwanted solar heat gain in
the cooling season. This saves electricity and lowers peak power demand by decreasing the
need for air conditioning. It can also cool the outside air, which can mitigate the urban heat
island effect and also improve air quality by slowing the reactions that produce smog. This
project quantified the energy savings, peak demand reduction, urban cooling, and air quality
improvements attainable from solar-reflective "cool" walls in California; collaborated with
industry to assess the performance of existing cool-wall technologies, and to develop innovative
cool-wall solutions; and worked with state and federal government agencies, utilities, and
industry to create a cool-wall infrastructure, including application guidelines, a product rating
program, incentives, and building code credits.
Simulations indicate that cool walls provide annual energy savings, peak demand reduction,
annual emission reduction, and summer heat island mitigation benefits comparable to those
yielded by cool roofs, and are helpful across California and in most of the southern half of the
United States (that is, in U.S. climate zones 1—4). Natural exposure trials conducted at three
sites in California and another three sites across the United States indicate that cool-wall
materials tend to stay clean and reflective. Significant advances were made in novel cool-wall
technologies, such as fluorescent cool pigments that expand the color palette for cool-wall
products. We prepared guidelines for the climate- and building-appropriate use of cool walls,
convened a stakeholder workshop, and created a working group. Ongoing efforts seek to
introduce or expand cool-wall provisions in building energy standards, green building
programs, and energy efficiency incentive programs, and to develop a cool-wall product rating
The surge in interval meter data availability and associated activity in energy data analytics has inspired new interest in advanced methods for building efficiency savings estimation. Statistical and machine learning approaches are being explored to improve the energy baseline models used to measure and verify savings. One outstanding challenge is the ability to identify and account for operational changes that may confound savings estimates. In the measurement and verification (M&V) context, 'non-routine events' (NREs) cause changes in building energy use that are not attributable to installed efficiency measures, and not accounted for in the baseline model's independent variables. In the M&V process NREs must be accounted for as 'adjustments' to appropriately attribute the estimated energy savings to the specific efficiency interventions that were implemented. Currently this is a manual and custom process, conducted using professional judgment and engineering expertise. As such it remains a barrier in scaling and standardizing meter-based savings estimation.
In this work, a data driven methodology was developed to (partially) automate, and therefore streamline the process of detecting NREs in the post-retrofit period and making associated savings adjustments. The proposed NRE detection algorithm is based on a statistical change point detection method and a dissimilarity metric. The dissimilarity metric measures the proximity between the actual time series of the post-retrofit energy consumption and the projected baseline, which is generated using a statistical baseline model. The suggested approach for NRE adjustment involves the NRE detection algorithm, the M&V practitioner, and a regression modeling algorithm. The performance of the detection and adjustment algorithm was evaluated using a simulation-generated test data set, and two benchmark algorithms. Results show a high true positive detection rate (75%-100% across the test cases), higher than ideal false positive detection rates (20%-70%), and low errors in energy adjustment (<0.7%). These results indicate that the algorithm holds for helping M&V practitioners to streamline the process of handling NREs. Moreover, the change point algorithm and underlying statistical principles could prove valuable for other building analytics applications such as anomaly detection and fault diagnostics.%B Energy and Buildings %V 185 %P 123 - 136 %8 01/2019 %G eng %U https://linkinghub.elsevier.com/retrieve/pii/S0378778818323259 %! Energy and Buildings %R 10.1016/j.enbuild.2018.12.020 %0 Report %D 2019 %T The Value Proposition for Cost-Effective, Demand Responsive-Enabling, Nonresidential Lighting System Retrofits in California Buildings %A Peter Schwartz %A Brian F. Gerke %A Jennifer Potter %A Alastair Robinson %A David Jagger %A Kelly Sanders %A Yao-Yung Wen %A Jasmine Shepard %A Teddy Kisch %X
Commercial lighting represents a significant potential source of demand response (DR) for the electrical grid, via traditional load shedding and rapid-dispatch (fast-DR) ancillary services when DR is enabled by networked lighting controls (NLCs). However, despite the significant opportunity and a regulatory push, DR-enabled lighting is installed in relatively few buildings because most building owners do not recognize its strong value proposition. Although NLCs can reduce energy bills, optimize facilities, and increase revenue, these co-benefits are not well quantified. This project analyzed lighting DR resources and energy-related co-benefits for commercial buildings in California. Using more than 100,000 individual hourly load profiles, the team forecasted the potential DR resources likely available from commercial lighting in 2025 and estimated revenues available from participation of these DR resources in energy markets. Combining these results with field-study estimates for NLC installation costs and energy savings provided a detailed accounting of site-level cost and energy-related co-benefits by building type from NLC's DR enablement. In many cases, energy savings alone can deliver significant net value, justifying NLC DR-enabled adoption. Additionally, the study considers the sometimes-larger non-energy benefits (NEBs).%8 04/2019 %G eng %0 Conference Proceedings %B ECEEE 2019 SUMMER STUDY %D 2019 %T What can connected thermostats tell us about American heating and cooling habits? %A Alan K. Meier %A Leo I. Rainer %A Abigail A. Daken %A Tsuyoshi Ueno %A Marco Pritoni %A Dan Baldewicz %X
At least five million American homes have Internet-connected thermostats. These devices improve comfort and reduce energy consumption using cloud-based algorithms. Every five minutes, they collect and transmit detailed operating information, including thermostat setpoints, actual indoor temperatures, occupancy, and HVAC operation.
One thermostat provider established a program that enables customers to anonymously "donate" their data to researchers and more than 50,000 customers have opted in. This dataset represents the most comprehensive public data on home temperature preferences for North America and provides far more detail than any previous method based on surveys or monitoring programs. The data show in detail preferred temperatures while occupants are home, sleeping, and away.
On average, these households lower their thermostats about 1°C when they are asleep compared to when awake, though this average conceals both widespread constant operation and deeper setbacks. The peak usage of air conditioners in Texas was shown to precisely match the grid's systemwide peak.
The connected thermostats also raise a survey research question: when should policymakers rely on a small sample of rigorously selected buildings instead of a huge, unrepresentative sample with detailed data? Many fruitful applications of this dataset will be constrained by privacy protections and reluctance of firms to share information.%B ECEEE 2019 SUMMER STUDY %G eng %U https://www.eceee.org/library/conference_proceedings/eceee_Summer_Studies/2019/4-monitoring-and-evaluation-for-greater-impact/what-can-connected-thermostats-tell-us-about-american-heating-and-cooling-habits/ %0 Conference Paper %B 2018 Summer Study on Energy Efficiency in Buildings %D 2018 %T Beyond Widgets: Validated Systems Energy Savings and Utility Custom Incentive Program Systems Trends %A Cynthia Regnier %A Paul A. Mathew %A Alastair Robinson %A Peter Schwartz %A Jordan Shackelford %A Travis Walter %K FLEXLAB %K incentive program %K Integrated systems %K lighting %K plug load controls %K systems %K task/ambient lighting %K utility %K utility custom programs %K workstation specific lighting %X
Energy efficiency upgrades to buildings to date through avenues such as utility incentive programs have been largely limited to component-based products (e.g., lamps, RTUs). While some utilities do provide 'custom' incentive programs with whole building and system level technical assistance, these programs require deeper levels of analysis, resulting in higher program costs. This results in custom programs being restricted to utilities with greater resources, and are typically applied mainly to large or energy-intensive facilities, leaving much of the market without cost effective access and incentives for these solutions. In addition, with increasingly stringent energy codes, cost effective component-based solutions that achieve significant savings are dwindling. Integrated building systems (e.g., integrated façade, HVAC and/or lighting solutions) can deliver higher savings (Regnier et al. 2017) that translate into large sector-wide savings if deployed at the scale of these programs. However, systems application poses a number of challenges – energy savings assessments are inherently more complex and are not easily suited to the deemed measure model, and implementation of systems can be more disruptive. This paper presents the outcomes of a project to develop validated utility incentive program packages for three specific integrated building systems, in collaboration with ComEd, a consortium of California Public Owned Utilities (CA POUs) (Northern California Power Agency(NCPA) and the Southern California Public Power Authority(SCPPA)), and Xcel Energy (CO, MN). Previous work described the potential for energy savings of these systems at the individual and market level, early test findings for the task-ambient lighting system, and described the work products to develop utility incentive programs (Regnier et al. 2016). This paper presents validated end use energy savings of all three systems showing energy savings of ~20% for automated shading combined with daylight dimming (does not include light fixture retrofit savings); 30-46% for task-ambient lighting systems combined with plug load occupancy controls, depending on technology package and office building size (no daylight dimming impacts); and ~94% in the south-façade daylit zone for workstation specific lighting systems with daylight dimming (including lighting retrofit and task tuning). Using a U.S. Department of Energy (DOE) reference building model (DOE 2018), this translates to whole building savings of 2-5% (large-medium commercial), 12-23% (large-small commercial), and 13-15% (medium-large commercial) for these systems respectively. Early findings from the utilities in deploying these systems through their incentive programs indicate that deployment methods such as direct install programs might be best suited for these integrated systems. Further, early findings from a scoping study across custom utility programs and federal retrofit programs indicate that component level retrofits are still prevalent even in these programs, pointing towards an opportunity for deeper energy savings deployment. High performance retrofit case studies demonstrate that deeper energy savings is possible through integrated approaches. Market stakeholder interviews indicate however that there is generally a low level of awareness of the potential for energy savings of these three integrated systems.%B 2018 Summer Study on Energy Efficiency in Buildings %8 08/2018 %G eng %U http://aceee.org/files/proceedings/2018/#/paper/event-data/p122 %R 10.20357/B7MS3M %0 Conference Proceedings %B ACEEE Summer Study on Energy Efficiency in Buildings %D 2018 %T Builder Installed Electrical Loads: The Energy Mortgage on a New House %A Leo I. Rainer %A Aditya Khandekar %A Alan K. Meier %X Builder-installed electrical loads (BIELs) are electrical appliances and components installed by the builder prior to occupancy that consume mains electricity. BIELs include products required by building codes, products expected by buyers, and/or products selected by the builder to make the house more attractive to buyers. Reducing the energy use of BIELs may provide an economical opportunity to reduce the miscellaneous electric load in homes, but BIELs are not well understood. To address this need whole house BIEL was measured in 17 new houses. Results showed an average total power of 128 watts, which represents an "energy mortgage" of $135/year before the owner even moves in. The largest loads found were from continuous ventilation fans required by code, but surprises like continuously illuminated street address signs and video doorbells, were also significant. Laboratory measurements of 35 life safety devices were performed to further characterize BIEL energy consumption. Strategies to reduce this energy use include: selection of lowest-power solutions, more efficient circuitry and power management, a separate DC circuit to serve DC-powered appliances, and use of energy-harvesting sensors and controls in place of grid-powered components. %B ACEEE Summer Study on Energy Efficiency in Buildings %C Pacific Grove, CA %G eng %U https://aceee.org/files/proceedings/2018/index.html#/paper/event-data/p029 %0 Report %D 2018 %T Building Innovation: A Guide For High-Performance Energy Efficient Buildings In India %A Reshma Singh %A Baptiste Ravache %A Dale A. Sartor %X
This Building Innovation Guide provides technical recommendations for achieving high-performance Indian office buildings that are smart, green, and energy efficient. the best practices recommended in the Guide are particularly suited to the climatic, cultural, and construction context of India, thereby offering localized solutions.%G eng %2 LBNL-2001147 %0 Report %D 2018 %T ComEd – LBNL 'Beyond Widgets' Project Automated Shading Integrated with Lighting and HVAC Controls System Program Manual %A Paul A. Mathew %A Cynthia Regnier %A Travis Walter %A Jordan Shackelford %G eng %2 LBNL-2001132 %0 Conference Paper %B 2018 Summer Study on Energy Efficiency in Buildings %D 2018 %T Do energy costs really affect commercial mortgage default risk? New results and implications for energy efficiency investments %A Paul A. Mathew %A Nancy Wallace %A Paulo Issler %A Baptiste Ravache %A Philip Coleman %A Cindy Zhu %K Commercial Mortgages %K default risk %K energy risk %X
This paper presents new results on the link between energy factors and commercial mortgage default. First, we summarize results from an empirical analysis of the impact of source energy use intensity (EUI) and electricity prices on mortgage default. We used a unique data set that merges building-level energy use data from city benchmarking ordinances and financial data for commercial mortgages on the same buildings. We found that building source EUI and electricity price are statistically and economically associated with commercial mortgage defaults. Next, we present five case studies on the impact of energy use and price variations on default risk: three office buildings, a hotel, and a multi-family residential building. We use the empirical model coefficients to compute the default risk impacts due to variations in source EUI and electricity price over the course of the mortgage term. We found that variations in source EUI could raise or lower the default rates in these properties by between 5% and 40%, depending on the property type and geography. Electricity pricing has an even greater effect – roughly 60% change in default rate in the Denver area and nearly 90% in northern California. Finally, we propose an energy risk score that lenders can use to assess energy risk and inform mortgage terms. The score is being developed and piloted in collaboration with three mortgage lenders. We conclude with implications of this score as a market signal and mechanism for incentivizing energy efficiency investments through the commercial mortgage channel.%B 2018 Summer Study on Energy Efficiency in Buildings %8 08/2018 %G eng %U http://aceee.org/files/proceedings/2018/#/paper/event-data/p217 %R 10.20357/B7W88T %0 Conference Paper %B 2018 Summer Study on Energy Efficiency in Buildings %D 2018 %T Driving Adoption of Demand-Responsive Commercial Lighting with a Clarified Value Proposition: Site Level Energy Savings and Cost-Benefit Analysis %A Brian F. Gerke %A Jennifer Potter %A Peter Schwartz %A Alastair Robinson %A David Jagger %A Jasmine Shepard %A Teddy Kisch %A Adel Suleiman %X
Commercial lighting represents a significant potential source of demand response (DR) for the electrical grid, via traditional load shedding and also via rapid-dispatch ("fast-DR") ancillary services when DR is enabled by networked lighting controls (NLCs). Since 2013, California Title 24 building code mandates DR-capable lighting in certain circumstances. Despite the significant opportunity and regulatory push, DR-enabled lighting is installed and enabled in a relatively small number of buildings because most building owners do not see a strong value proposition from DR-enabled lighting. While NLCs can support DR enablement by providing additional capabilities that deliver value to the customer such as reduced energy bills, optimized space utilization, and increased revenue, these co-benefits from NLCs are not well quantified. This paper undertakes a detailed analysis of lighting DR resources and energy-related co-benefits for commercial buildings in California. Using over 100,000 individual hourly load profiles, we forecast the potential DR resources that could be available from commercial lighting in 2025. We also estimate the revenues available from participation of these DR resources in energy markets. Combining these results with field-study estimates for NLC installation costs and energy savings, we perform a detailed accounting, by building type, of the site-level costs and energy-related co-benefits arising from DR enablement with NLCs. In many cases, the energy savings alone can deliver significant net value to the site, strongly justifying the adoption of NLC-enabled DR. A companion paper considers the additional non-energy benefits, which can be even larger than the energy benefits.%B 2018 Summer Study on Energy Efficiency in Buildings %C Pacific Grove, CA %8 08/2018 %G eng %0 Journal Article %J Desalination %D 2018 %T Energy considerations associated with increased adoption of seawater desalination in the United States %A Prakash Rao %A William R. Morrow III %A Arian Aghajanzadeh %A Paul Sheaffer %A Caroline Dollinger %A Sabine Brueske %A Joe Cresko %K desalination %K water-energy nexus %X
Due in part to increased water demand and uncertainty around the availability of existing freshwater resources, there is interest in expanding the use of seawater desalination in the U.S. In order for greater adoption to occur, existing barriers need to be mitigated. One of these barriers is the energy consumption of seawater desalination. This paper reviews the existing energy requirements for membrane and thermal-based seawater desalination systems to produce potable water. Through literature review, it identifies the commercially-available option with the lowest energy intensity and the thermodynamic minimum energy requirement for each unit operation of the system. The paper then estimates the energy requirements to expand seawater desalination capacity to meet the potable water needs of water-stressed regions in the U.S. The results show that supplying 10% of the potable water demand for these regions located within 250 miles of a coastline using the lowest energy-intensity seawater desalination system commercially available would require <0.1% of 2018 U.S. electricity consumption. This increases to approximately 0.5% if all public water for these same regions is supplied via desalinated seawater. These estimates of the energy implications of broader adoption provide an initial comparison to current U.S. electricity consumption.%B Desalination %V 445 %P 213 - 224 %8 11/2018 %G eng %U https://linkinghub.elsevier.com/retrieve/pii/S0011916418310919https://api.elsevier.com/content/article/PII:S0011916418310919?httpAccept=text/xmlhttps://api.elsevier.com/content/article/PII:S0011916418310919?httpAccept=text/plain %! Desalination %R 10.1016/j.desal.2018.08.014 %0 Report %D 2018 %T Energy Cost Savings of Systems-Based Building Retrofits: A Study of Three Integrated Lighting Systems in Comparison with Component Based Retrofits %A Cynthia Regnier %A Paul A. Mathew %A Alastair Robinson %A Peter Schwartz %A Jordan Shackelford %A Travis Walter %X
Most building retrofit projects are still component-based in that they typically address only one piece or type of equipment at a time. Systems-based retrofits that seek to address multiple components in an integrated manner have the potential to provide significantly greater energy savings.
Lawrence Berkeley National Laboratory (LBNL) partnered with several utilities to develop and evaluate three different integrated retrofit packages involving lighting systems: automated shading with daylight dimming controls, workstation-specific lighting with daylight controls, and task/ambient lighting with plug load occupancy controls. Specifically, our analysis sought to quantify the marginal benefits of these systems (energy savings as well as lighting performance and visual comfort) relative to component- based approaches. The analysis was based on a combination of measured performance data from LBNL's FLEXLAB® test facility and energy simulations. All three systems were compared to a simple fluorescent-to-LED retrofit, which represents the component-based approach. While the simple LED upgrade provides significant lighting energy savings of 63%, the systems yielded energy savings of 81- 93%, which equates to additional savings of 49-82% over the simple LED upgrade (Table A-1).1 All systems tested provided satisfactory visual comfort as well, indicating good potential for market acceptance.
We estimate post-meter methane (CH4) emissions from California's residential natural gas (NG) system using measurements and analysis from a sample of homes and appliances. Quiescent whole-house emissions (i.e. pipe leaks and pilot lights) were measured using a mass balance method in 75 California homes, while CH4 to CO2 emission ratios were measured for steady operation of individual combustion appliances and, separately, for transient operation of three tankless water heaters. Measured quiescent whole-house emissions are typically < 1 g CH4/day, though exhibit long tailed gamma distributions containing values > 10 g CH4/day. Most operating appliances yield undetectable CH4 to CO2 enhancements in steady operation (< 0.01% of gas consumed), though storage water heaters and stove-tops exhibit long tailed gamma distributions containing high values (~ 1-3% of gas consumed), and transients are observed for the tankless heaters. Extrapolating results to the state-level using Bayesian Markov chain Monte Carlo sampling combined with California housing statistics and gas use information suggests quiescent house leakage of 23.4 (13.7 – 45.6, at 95% confidence) Gg CH4, with pilot lights contributing ~ 30%. Emissions from steady operation of appliances and their pilots is 13.3 (6.6 – 37.1) Gg CH4/yr, an order of magnitude larger than current inventory estimate, with transients likely increasing appliance emissions further. Together, emissions from residential NG are 35.7 (21.7 – 64.0) Gg CH4/yr, equivalent to ~ 15% of California's NG CH4 emissions, suggesting leak repair, improvement of combustion appliances, and adoption of non-fossil energy heating sources can help California meet its 2050 climate goals.%B Environmental Science & Technology %8 02/2018 %G eng %! Environ. Sci. Technol. %R 10.1021/acs.est.8b03217 %0 Journal Article %J Energy and Buildings %D 2018 %T A Framework for Monitoring-Based Commissioning: Identifying Variables That Act as Barriers and Enablers to the Process %A Nora Harris %A Tripp Shealy %A Hannah Kramer %A Jessica Granderson %A Georg Reichard %K challenges %K drivers %K EMIS %K motivators %X
The practice of monitoring-based commissioning (MBCx) using energy management and information systems (EMIS) has been shown to enable and help sustain up to 20% energy savings in buildings. Despite research that has quantified the costs, benefits, and energy savings of MBCx, the process remains under-utilized. To understand why MBCx is not more frequently adopted and how to encourage its use, this research synthesizes qualitative data from over 40 organizations, currently engaging in MBCx. The outcome of this research is a framework containing variables that emerged from the qualitative data, marked as barriers or enablers, organized by phases of the MBCx process. The framework is comprised of 51 emergent variables that fall within 13 different categories. The variables that most frequently act as barriers are data configuration, measurement & verification (M&V), developing specifications for EMIS, and data architecture. Although some variables that act as barriers for one organization were identified as enablers for another. For example, payback/ROI was considered a barrier 7 times and an enabler 3 times. One organization had difficulty making the business case for the initial investment for MBCx due to lack of cost information, while another was able to justify large investments with documented savings of previously implemented measures identified through MBCx. The framework formally validates barriers found in previous research, and can be used by practitioners to better understand common experiences with MBCx. This research highlights the need for a similar collective data set to validate common enablers to MBCx and also the need for empirical research to determine relationships between variables.%B Energy and Buildings %V 168 %P 331 - 346 %8 06/2018 %G eng %! Energy and Buildings %R 10.1016/j.enbuild.2018.03.033 %0 Journal Article %J Energy and Buildings %D 2018 %T Full scale laboratory experiment on the cooling capacity of a radiant floor system %A Jovan Pantelic %A Stefano Schiavon %A Baisong Ning %A Eleftherios Burdakis %A Paul Raftery %A Fred S. Bauman %X
Direct solar radiation on a cooled radiant floor increases its cooling capacity. There is limited measured evidence of this phenomenon reported in the literature. We assessed the effect of solar radiation, increased air movement, and carpet on the cooling capacity of the radiant floor in a laboratory exposed to the outside environment. We performed experiments for different chilled water supply temperature. The cooling capacity of the chilled radiant floor was measured to increase from 32 up to 110 W/m2 under direct solar radiation. The surface temperature region exposed to solar radiation reached a peak temperature of 26°C while the unexposed areas were between 20 and 21°C. Increasing the chilled water supply temperature from 12 to 18°C caused a decrease in cooling capacity from ∼110 to ∼95 W/m2. Higher air speeds along the floor created by ceiling fans increased the radiant slab cooling capacity by ∼12% (from 32 to 36 W/m2) when the operative temperature was 24°C and, up to ∼19% (40 W/m2) when it is increased to 26°C. The presence of thin carpet tiles reduced the radiant floor cooling capacity for ∼5% compared to an exposed floor slab.%B Energy and Buildings %V 170 %G eng %& 134 %R 10.1016/j.enbuild.2018.03.002 %0 Journal Article %J Energy Efficiency %D 2018 %T A Library of Building Occupant Behaviour Models Represented in a Standardised Schema %A Zsofia Belafi %A Tianzhen Hong %A Andras Reith %K building performance simulation %K obXML %K Occupant Behaviour %K occupant behaviour model %K XML schema %X
Over the past four decades, a substantial body of literature has explored the impacts of occupant behaviour (OB) on building technologies, operation, and energy consumption. A large number of data-driven behavioural models have been developed based on field data. These models lack standardisation and consistency, leading to difficulties in applications and comparison. To address this problem, an ontology was developed using the drivers-needs-actions-systems (DNAS) framework. Recent work has been carried out to implement the theoretical DNAS framework into an eXtensible Markup Language (XML) schema, titled 'occupant behaviour XML' (obXML) which is a practical implementation of OB models that can be integrated into building performance simulation (BPS) programs. This paper presents a newly developed library of OB models represented in the standardised obXML schema format. This library provides ready-to-use examples for BPS users to employ more accurate occupant representation in their energy models. The library, which contains an initial effort of 52 OB models, was made publicly available for the BPS community. As part of the library development process, limitations of the obXML schema were identified and addressed, and future improvements were proposed. Authors hope that by compiling this library building, energy modellers from all over the world can enhance their BPS models by integrating more accurate and robust OB patterns.%B Energy Efficiency %G eng %R 10.1007/s12053-018-9658-0 %0 Conference Paper %B 39th AIVC Conference %D 2018 %T Measured Pollutant Performance of Island Overhead Kitchen Exhaust %A Iain S. Walker %A Gabriel Rojas %A Jordan D. Clark %K indoor air quality %K Kitchen ventilation %K Range hoods %K Source reduction %X
Cooking is one of the most substantial sources of indoor air pollution in most residences.
This is mitigated most often by exhaust devices located near cooking surfaces. In this study,
we measured the efficacy of one type of kitchen ventilation device: an island overhead
kitchen exhaust. Laboratory tests using tracer gas capture were performed on a full-scale
mock-up of a kitchen with a cooktop in an island. The results show that the Capture
Efficiency (CE) varies greatly from about 10% to nearly 100%. CE generally increased with
exhaust flow rate, but results did not show clear trends when changing hood mounting
height or the power input to the cooktop burners. Burner power had an effect on measured
capture efficiency of the same magnitude as exhaust flow rate. As with earlier work on wallmount
exhaust hoods, these results indicate that standardized testing will have to clearly
specify mounting heights, power input (and or temperatures) and the geometry of the
tracer gas emitter.
We present a novel pulsed flow control method (PFM) using a two-position valve to regulate the capacity of radiant slab systems. Under PFM, the on-time duration of the valve is short (compared to all prior work, e.g. 4-minute), and fixed, while the off-time varies. We present a novel, open-source, finite difference model that assesses three-dimensional transient slab heat transfer, accounting for the transient heat storage of the pipe fluid. Sensitivity analysis results indicate the dominant factors influencing energy performance of the PFM are: on-time duration; pipe diameter; and spacing. We experimentally validated both the new control strategy and model in full-scale laboratory experiments. Compared with previous intermittent control strategies (with on-time durations over 30 min), at 50% part load the PFM reduces 27% required water flow rate and increases supply to return water temperature differential. Compared with the variable temperature control method, at 50% part load the PFM reduces 24% required water flow rate. The energy performance of PFM is comparable to that of a conventional variable flow rate control. However, it has more accurate capacity control, achieves a more uniform surface temperature distribution, and reduces initial investment by substituting two-position for modulating valves, thus showing promise for engineering applications.
Building retrofits provide a large opportunity to significantly reduce energy consumption in the buildings sector. Traditional building retrofits focus on equipment upgrades, often at the end of equipment life or failure, and result in replacement with marginally improved similar technology and limited energy savings. The Integrated System (IS) retrofit approach enables much greater energy savings by leveraging interactive effects between end use systems, enabling downsized or lower energy technologies. This paper presents a case study in Hawaii quantifying the benefits of an IS retrofit approach compared to two traditional retrofit approaches: a Standard Practice of upgrading equipment to meet minimum code requirements, and an Improved Practice of upgrading equipment to a higher efficiency. The IS approach showed an energy savings of 84% over existing building energy use, much higher than the traditional approaches of 13% and 33%. The IS retrofit also demonstrated the greatest energy cost savings potential. While the degree of savings realized from the IS approach will vary by building and climate, these findings indicate that savings on the order of 50% and greater are not possible without an IS approach. It is therefore recommended that the IS approach be universally adopted to achieve deep energy savings.%B Energy and Buildings %V 159 %G eng %R 10.1016/j.enbuild.2017.10.090 %0 Journal Article %J Energy and Buildings %D 2018 %T Side-by-side laboratory comparison of space heat extraction rates and thermal energy use for radiant and all-air systems %A Jonathan Woolley %A Stefano Schiavon %A Fred S. Bauman %A Paul Raftery %A Jovan Pantelic %X
Radiant cooling systems extract heat from buildings differently than all-air cooling systems. These differences impact the time and rate at which heat is removed from a space, as well as the total amount of thermal energy that a mechanical system must process each day. In this article we present measurements from a series of multi-day side-by-side comparisons of radiant cooling and all-air cooling in a pair of experimental testbed buildings, with equal heat gains, and maintained at equivalent comfort conditions (operative temperature). The results show that radiant cooling must remove more heat than all-air cooling – 2% more in an experiment with constant internal heat gains, and 7% more with periodic scheduled internal heat gains. Moreover, the peak sensible space heat extraction rate for radiant cooling (heat transfer at the cooled surface, not the cooling plant) must be larger than the peak sensible space heat extraction rate for all-air systems, and it must occur earlier. The daily peak sensible space heat extraction rate for the radiant system was 1–10% larger than for the all air system, and it occurred 1–2 hours earlier. These findings have consequences for the design of radiant systems. In particular, this study confirms that cooling load estimates for all-air systems will not represent the space heat extraction rates required for radiant systems.%B Energy and Buildings %V 176 %G eng %& 139 %R 10.1016/j.enbuild.2018.06.018 %0 Report %D 2018 %T Stasis PCM Test Results %A Baptiste Ravache %A Cynthia Regnier %K FLEXLAB %X
A phase change material product distributed by Stasis Group, designed to reduce the cooling energy requirements of multi-story commercial buildings, was tested in a side-by-side comparison at FLEXLAB® (LBNL, 2018), a calibrated test facility for low energy building technology solutions. The product was installed according to Stasis recommendations in the ceiling plenum of a 600 ft2 cell representative of an office space, while an identical cell was operated in the same conditions, except for the night-time pre-cooling sequence and without the product, to gather baseline data. The cells were operated to replicate summer conditions of a candidate office building for retrofit. For the tests conducted at FLEXLAB, two Phase Change Material (PCM) compositions were tested, with the second product having an upgraded composition for thermal performance and upgraded packaging that was used to meet with fire safety requirements for a plenum application.
Two rounds of tests were performed, which were designed to collect data for both core (designated as Round 1) and perimeter (Round 2) office space conditions. Following the analysis of the data collected during Round 1, the experimental design was modified to better represent the thermal conditions of a typical office space in relation to the PCM performance. A new product was also brought in for testing in Round 2, which had an improved operational temperature range and packaging properties. In Round 1, multiple tests were conducted to evaluate the performance of the product under different conditions of internal loads, temperature setpoints, pre-cooling strategies and temperature control strategies. In Round 2, the internal conditions were kept constant, while the test conditions only differ in the amount of PCM installed in the test cell plenum and the length of the nighttime pre-cooling sequence.
The performance benefits of PCM are generally two-fold: the material may reduce peak cooling energy use during daytime hours (a peak demand energy use benefit) and may allow for energy savings with pre-cooling at night through night flush HVAC controls when night time outside air temperatures are lower, and fan energy use for cooling is more efficient than the use of daytime compressor-based cooling. The focus of this research project was mainly on quantifying the energy savings potential of the latter case although some effects on peak reduction were noted. Between the cell with PCM and nighttime precooling and the reference cell without PCM or precooling, a reduction in cooling load during occupied hours was noted between 7.6 kWh (or 22% of occupied hours cooling load) and 12.5 kWh (or 33% of occupied hours cooling load). Future work can further evaluate the peak cooling load reduction benefits of this product in more detail.
In Round 1, the results for the original product tested showed limited potential for shifting cooling load between occupied hours and nighttime, when compared to a baseline office that uses the same pre-cooling strategy without PCM. A significant shift in cooling load can be observed when the baseline cell does not use any pre-cooling strategies. That shift could be attributed to the thermal mass of the envelope of the cell or from the sensible and latent heat of the PCM, but the sources of the shift are not easily distinguishable.
The test conditions that were developed during the project proposal stage were investigated and we discovered by going in the test cell during different stages of the cycle and physically testing the material, that the PCM product was not performing at the freeze and melt conditions expected. Further tests were conducted to investigate the discrepancies between performance and expectations. A combination of factors was identified as the source of the limited energy savings and those factors were helpful in determining the potential issues that could hinder the performance of the PCM when installed in real buildings. This work was used to design product improvements and the re-design of the second round of experiments. Overall, the results of the Round 1 testing provided valuable insights into experimental design conditions to help discern the PCM's performance, as well as the desired thermal performance of the PCM product, which informed the development of the improved PCM product.
In Round 2, the combination of PCM and nighttime pre-cooling was shown to provide load shifting, which can in part be attributed to the PCM. This load shifting from daytime to nighttime can be used to reduce the HVAC energy use, by replacing mechanically cooled return air with outside air at night, and the daily cost of energy, assuming lower rates at night (not evaluated in this report). Compared to the baseline case, which did not include a pre-cooling strategy, the PCM plus pre-cooling strategy resulted in 12-18% daily HVAC energy savings.
This report highlights the results of Round 2, which reflect the performance of the modified PCM product when operated in suitable conditions. The results of Round 1, along with an analysis of the experimental data to identify the factors that prevented the product from performing as desired are presented in Appendix B.
The following table gives an overview of the results obtained during the Round 2 experiments. The results are given as the daily cooling load (including pre-cooling) and as the HVAC energy, which includes fans and cooling energy, assuming a cooling efficiency of 1 kW/RT (i.e. 1 kW of electricity is needed to produce 1 refrigerant ton – or 3.51 kW of cooling) and assuming that pre-cooling is done with 100% outside air, which corresponds to the optimal condition for cooling energy savings. In practice, the chiller plant efficiency will vary depending on several factors, including outside air temperature, however the use of a varying efficiency was outside of the scope of this study, and should be the focus of future work. In Table 1 'Ref' and 'Test' refers to the reference cell (without PCM) and the test cell (with PCM). Positive savings means that the test cell has a lower HVAC consumption than the reference cell. Overall, the PCM product used in Round 2 demonstrated a savings ranging from 12% to 18% depending on the amount of installed PCM, and the length of time the test cell used night time outside air-based pre-cooling.%G eng %2 2001162 %0 Report %D 2017 %T AUTOMATED REGISTER V1.0.3: User Manual for Using the Automated Register of Implemented Actions %A Arian Aghajanzadeh %A Aimee T. McKane %A Paul Sheaffer %A Peter L. Therkelsen %A Prakash Rao %K implemented actions %K Manual %X
The Automated Register of the Implemented Actions (The "Register") is designed to assist you in your path towards Superior Energy Performance (SEP®) certification and complements the SEP® Measurement and Verification (M&V) Protocol.
Completion of this Register does not guarantee certification. If you are not pursuing SEP® certification, you can still use this Register to organize and track your energy performance. This Register will summarize the key details of the implementation of each action, including action description, actual energy savings, source of energy savings determination, and responsible party. All actions affecting the energy performance improvement over the achievement period should be included, regardless of whether the action is associated with ISO 50001 "Action Plans" or "Significant Energy Uses". The Register should reflect energy savings over the reporting period; typically, this will be annual savings.%I Lawrence Berkeley National Laboratory %C Berkeley %8 06/2017 %2 LBNL-2001022 %0 Journal Article %J Environmental Science & Technology %D 2017 %T Bioenergy Potential from Food Waste in California %A Hanna Breunig %A Ling Jin %A Alastair Robinson %A Corinne Scown %X
Inefficiencies occur at all stages of the food supply chain, linked to complex factors ranging from market conditions and weather to consumer preferences, and these inefficiencies translate to an abundance of food waste. The U.S. generated approximately 38 million tonnes of municipal food waste in 2014, approximately 95% of which was landfilled. An enormous amount of energy, water, land, and other resources go into producing nutrition for humans. A recent analysis of food waste estimated that $218 billion is spent in the U.S. on growing, processing, transporting, and disposing of food and byproducts that go uneaten. Furthermore, because food waste biodegrades four times faster than typical paper products and 10 times faster than wood waste, it releases methane from landfills more quickly than most other organic waste, with 34–51% of generated methane escaping typical landfill gas capture systems. Landfilling uneaten solid organic material not only contributes to climate change and occupies land resources, but also eliminates the possibility of cycling the valuable nutrients and energy in food back into the economy.
First and foremost, policy measures are necessary to ensure source-reduction through changes in consumer behavior and improved harvesting, processing, and transportation methods. However, source-reduction alone will not be a sufficient strategy. Americans consume raw produce and livestock that have both edible and inedible parts, from local and nonlocal sources, and in quantities that require some level of centralized production and distribution. These biological materials can only be used for their original purpose—to provide nutrition and sustenance to humans—for a short window of time, and maintaining the value of food is not always possible. Food waste-to-energy strategies can help meet renewable energy targets, greenhouse gas (GHG) reduction targets, air quality standards, and divert waste from landfills.
In this paper, the potential for converting California's food waste to electrical and thermal energy is analyzed, including organic waste from the food supply chain: agricultural production, postharvest handling and storage, processing and packaging, distribution, consumption, and end-of-life. The objectives of this study are to determine the quantity, locations, and temporal variation in food waste generation, use these results to model regional and subannual electricity and heat generation potential, and gain insight into the roles of policy and technology in overcoming challenges associated with food waste utilization. California serves as a useful starting point for building an analysis framework that can be applied to the U.S. or globally because of its diversity and significance in national food production (40% of U.S. vegetables, 20% of dairy, and 70% of fruits, tree nuts, and berry production by revenue). Although previous assessments have estimated the total annual energy potential from food waste from retail and consumer waste streams and from food processors in California, this study is the first to assess food waste production at the subannual scale and to develop a spatially and temporally explicit model that integrates feedstock production and energy infrastructure capacity to estimate potential energy production. By accounting for infrastructure, logistics, and storage limitations, this study provides a more robust assessment of potential electricity and thermal energy generation and highlights key challenges that must be overcome to maximize this potential.%B Environmental Science & Technology %8 01/2017 %2 LBNL-1007105 %R 10.1021/acs.est.6b04591 %0 Conference Paper %B Building Simulation 2017 %D 2017 %T Calculating the Effect of External Shading on the Solar Heat Gain Coefficient of Windows %A Christian Kohler %A Yash Shukla %A Rajan Rawal %X
Current prescriptive building codes have limited ways to account for the effect of solar shading, such as overhangs and awnings, on window solar heat gains. We propose two new indicators, the adjusted Solar Heat Gain Coefficient (aSHGC) which accounts for external shading while calculating the SHGC of a window, and a weighted SHGC (SHGCw) which provides a seasonal SHGC weighted by solar intensity. We demonstrate a method to calculate these indices using existing tools combined with additional calculations. The method is demonstrated by calculating the effect of an awning on a clear double glazing in New Delhi.%B Building Simulation 2017 %C San Francisco, CA %8 08/2017 %G eng %2 LBNL-2001057 %0 Report %D 2017 %T California Publicly‐Owned Utilities (POUs) – LBNL 'Beyond Widgets' Project Task‐ambient lighting and occupancy‐based plug load control System Program Manual %A Alastair Robinson %A Paul A. Mathew %A Cynthia Regnier %A Peter Schwartz %A Jordan Shackelford %A Travis Walter %K incentive program %K Integrated systems %K systems %K utilities %X
This program manual contains detailed technical information for implementing an incentive program for task‐ambient lighting and occupancy‐based plug load control. This manual was developed by Lawrence Berkeley National Laboratory, in collaboration with the California Publicly‐Owned Utilities (CA POUs) as a partner in the 'Beyond Widgets' program funded by the U.S. Department of Energy Building Technologies Office. The primary audience for this manual is the program staff of the various CA POUs. It may also be used by other utility incentive programs to help develop similar programs.
It is anticipated that the content of this manual be utilized by the CA POU staff for developing related documents such as the Technical Resource Manual and other filings pertaining to the roll‐out of an energy systems‐based rebate incentive program.%8 09/2017 %G eng %2 LBNL-2001130 %0 Conference Paper %B AIVC Conference %D 2017 %T Comparing extracting and recirculating residential kitchen range hoods for the use in high energy efficient housing %A Gabriel Rojas %A Iain S. Walker %A Brett C. Singer %K Capture Efficiency %K Extracting range hood %K Kitchen ventilation %K Recirculating range hood %X
Residential cooking can be a significant indoor source of odour, pollutants and particulate matter. Conventionally, range hoods expel the air into the ambient. A number of studies have investigated their contaminant capture performance. However, for highly energy efficient houses the installation of extracting range hoods can pose certain challenges, e.g. high ventilation losses, additional thermal bridges and potential air leakage sites. Therefore, the use of recirculation range hoods has become standard for highly energy efficient housing with mechanical ventilation with heat recovery in Central Europe.
Open questions remain regarding their capture and filtration efficiency as a function of filter age, especially for particles and odours. But also, the actual energy savings potential when using recirculating instead of extracting devices in a highly energy efficient housing had not been documented yet. This paper addresses these questions with a literature review and an energetic comparison.
The review identified a good number of studies which have investigated the capture performance of extracting range hoods with a focus on pollutants resulting from gas combustion and/or the cooking generated particles. These studies show that capture efficiency, in particular for front burner use, can vary drastically for different designs and that particle capture does not necessarily match capture efficiency for gaseous contaminants. No scientific study investigating the performance of recirculating range hoods was found. Tests for consumer magazines as well as surveys indicate notably lower performance compared to extracting hoods. In summary one can say that performance tests are urgently needed to quantify the capture and filter efficiency for particles and (odorous) organic compounds as a function of filter age.%B AIVC Conference %G eng %R 10.20357/B7201Z %0 Conference Paper %B Building Simulation 2017 %D 2017 %T Development of Automated Procedures to Generate Reference Building Models for ASHRAE Standard 90.1 and India's Building Energy Code and Implementation in OpenStudio %A Andrew Parker %A Philip Haves %A Subhash Jegi %A Vishal Garg %A Baptiste Ravache %X
This paper describes a software system for automatically generating a reference (baseline) building energy model from the proposed (as-designed) building energy model. This system is built using the OpenStudio Software Development Kit (SDK) and is designed to operate on building energy models in the OpenStudio file format.%B Building Simulation 2017 %C San Francisco, CA %8 08/2017 %G eng %2 LBNL-2001052 %0 Report %D 2017 %T Energy and environmental consequences of a cool pavement campaign %A Haley E. Gilbert %A Pablo J. Rosado %A George A. Ban-Weiss %A John T. Harvey %A Hui Li %A Benjamin H. Mandel %A Dev Millstein %A Arash Mohegh %A Arash Saboori %A Ronnen M. Levinson %K Building energy %K conditioning %K Cool Pavements %K cooling %K heating %K life cycle assessment (LCA) %K materials and construction %K pavements %K urban climate %X
Raising the albedo (solar reflectance) of streets can lower outside air temperature, reduce building energy use, and improve air quality in cities. However, the production and installation of pavement maintenance and rehabilitation treatments with enhanced albedo ("cool" pavements) may entail more or less energy consumption and carbon emission that of less-reflective treatments. We developed several case studies in which a cool surface treatment is substituted for a more typical treatment (that is, a cool technology is selected instead of a more typical technology). We then assessed over a 50-year analysis period the changes in primary energy demand (PED, excluding feedstock energy) and global warming potential (GWP, meaning carbon dioxide equivalent) in Los Angeles and Fresno, California. The analysis considers two stages of the pavement life cycle: materials and construction (MAC), comprising material production, transport, and construction; and use, scoped as the influence of pavement albedo on cooling, heating, and lighting energy consumption in buildings.
In Los Angeles, substituting a styrene acrylate reflective coating or a chip seal for a slurry seal in routine maintenance, or a bonded concrete overlay on asphalt (BCOA) without supplementary cementitious materials (SCM) for mill-and-fill asphalt concrete in conventional or long-life rehabilitation, induced MAC-stage PED and GWP penalties that substantially exceeded use-stage savings, primarily due to material production. Modified rehabilitation cases in which SCM comprised 21% to 50% of the BCOA's total cementitious content by mass (portland cement + SCM) yielded smaller total (MAC + use) PED and GWP penalties, or even total PED and GWP savings. Trends in Fresno were similar, with some differences in GWP outcomes that result from Fresno's longer heating season.
The modified rehabilitation cases using BCOA with high SCM content yielded total GWP savings in each city; all other cases yielded total GWP penalties. The magnitude of the one-time GWP offset offered by global cooling from the increased albedo itself always, and sometimes greatly, exceeded the 50-year total GWP penalty or savings.
In Los Angeles, the annual building conditioning (cooling + heating) PED and energy cost savings intensities yielded by cool pavements were each about an order of magnitude smaller than the corresponding savings from cool roofs.%8 05/2017 %0 Report %D 2017 %T An Energy-focused Profile of the Video Gaming Marketplace %A Evan Mills %A Norman Bourassa %A Leo I. Rainer %A Jimmy Mai %A Louis-Benoit Desroches %A Arman Shehabi %A Ted Pollak %A Nathaniel Mills %X
Gaming is a major social and technological phenomenon, engaged in by a third to a half of humanity. The associated energy use has been understudied, and passed over in most energy policy and planning initiatives. This report reviews available energy-relevant information on the non-battery-powered video gaming market, including associated technology trends and gaps in the consumer information environment. We develop a profile of the California marketplace for the purposes of performing energy analysis. The resulting analytical platform is based on best-available data and industry expert opinions. Constituent data include an array of 25 individual gaming systems, operated by four user types across multi-step duty cycles, and running a representative assortment of game titles. This market segmentation spans the spectrum of gaming experience, system performance, and power requirements, and is leveraged to develop a characterization of the installed base of gaming equipment and its use. We find that there are currently more than 15 million video-gaming devices in use in California. While the absolute number is projected to decline somewhat in response to the increasing popularity of mobile gaming, the mix of platforms and their applications will shift towards increasingly energy-intensive configurations. This analysis also sheds light on significant energy efficiency improvements occurring in the marketplace and other drivers of energy demand. In subsequent phases of this project, the specified gaming systems will be bench-tested and the results used to generate aggregate baseline energy demand assessments for California and scenarios for the future.%8 06/2017 %G eng %0 Conference Paper %B AIVC Conference %D 2017 %T Evaluating the Performance of Island Kitchen Range Hoods %A Iain S. Walker %A Gariel Rojas %A Jordan D. Clark %A Max H. Sherman %K Cooking %K indoor air quality %K Kitchen ventilation %K Performance Standard %K range hood %X
A key aspect of achieving acceptable indoor air quality is source control. Cooking has been recognized as a significant source of pollutants for health impacts (e.g., PM2.5 and NO2) as well as moisture and odour. A common method of controlling this pollutant source is by using a range (or cooker) hood that vents to outside. However, field and laboratory experiments have shown highly variable performance for these devices. We use the capture efficiency metric (the fraction of the pollutants that are exhausted to outside at steady state) to characterize the range hood performance. To address this issue and provide useful information for builders, contractors, designers and home occupants, a laboratory rating method for range hood capture efficiency has recently been developed by LBNL and ASTM. The test method uses standardized emitters to create a heated plume and seed it with tracer gas. The tracer gas measurements in the room, the range hood exhaust and in the ambient air are used to estimate capture efficiency. However, this test method only applies to wall-mounted range hoods. Some range hoods are not wall-mounted: island range hoods are designed to operate over a cooktop in the middle of a room rather than against a wall and downdraft hoods draw air from near the cooktop rather than overhead. This paper discusses the development of a new test apparatus for island and downdraft hoods and presents measured capture efficiency data from example hoods. The results of this work will be used in future revisions to the ASTM standard.%B AIVC Conference %G eng %R 10.20357/B75P4X %0 Report %D 2017 %T A high turndown, ultra low emission low-swirl burner for natural gas, on-demand water heaters %A Vi H. Rapp %A Robert K. Cheng %A Peter L. Therkelsen %X
Previous research has shown that on-demand water heaters are, on average, approximately 37% more efficient than storage water heaters. However, approximately 98% of water heaters in the U.S. use storage water heaters while the remaining 2% are on-demand. A major market barrier to deployment of on-demand water heaters is their high retail cost, which is due in part to their reliance on multi-stage burner banks that require complex electronic controls. This project aims to research and develop a cost-effective, efficient, ultra-low emission burner for next generation natural gas on-demand water heaters in residential and commercial buildings. To meet these requirements, researchers at the Lawrence Berkeley National Laboratory (LBNL) are adapting and testing the low-swirl burner (LSB) technology for commercially available on-demand water heaters. In this report, a low-swirl burner is researched, developed, and evaluated to meet targeted on-demand water heater performance metrics. Performance metrics for a new LSB design are identified by characterizing performance of current on-demand water heaters using published literature and technical specifications, and through experimental evaluations that measure fuel consumption and emissions output over a range of operating conditions. Next, target metrics and design criteria for the LSB are used to create six 3D printed prototypes for preliminary investigations. Prototype designs that proved the most promising were fabricated out of metal and tested further to evaluate the LSB's full performance potential. After conducting a full performance evaluation on two designs, we found that one LSB design is capable of meeting or exceeding almost all the target performance metrics for on-demand water heaters. Specifically, this LSB demonstrated flame stability when operating from 4.07 kBTU/hr up to 204 kBTU/hr (50:1 turndown), compliance with SCAQMD Rule 1146.2 (14 ng/J or 20 ppm NOX @ 3% O2), and lower CO emissions than state-of-the art water heaters. Overall, the results from this research show that the LSB could provide a simple, low cost burner solution for significantly extending operating range of on-demand water heaters while providing low NOX and CO emissions.%8 03/2017 %2 LBNL-1007236 %0 Report %D 2017 %T Impact of Energy Use and Price Variations on Default Risk in Commercial Mortgages: Case Studies %A Paul A. Mathew %A Kaiyu Sun %A Baptiste Ravache %A Paulo Issler %A Nancy Wallace %X
This report documents the impact of energy use and price variations on commercial mortgage default risk in five buildings: an office building in the Denver area, two office buildings in northern California, a hotel in the Denver area, and a multi-family residential building in San Francisco. We used parametric energy simulation to analyze the impact of variations in operational practices on source energy use intensity (EUI). We then computed the impact of source EUI variations on default risk using coefficients from an empirical logistic regression model developed earlier in this research effort as documented in Wallace et al. [2017]. Table 1 shows the relative range of variation in source EUI and default risk for each building. The table also shows the default rate variation relative to the TREPP average default rate of 800 basis points (8%).%8 09/2017 %G eng %2 LBNL-2001112 %0 Report %D 2017 %T ISO 50001 and SEP Faster and Cheaper - Exploring the Enterprise-Wide Approach %A Jingjing Liu %A Prakash Rao %A Peter L. Therkelsen %A Paul Sheaffer %A Paul Scheihing %A Yannick Tamm %K ISO 50001 %X
ISO 50001 and other management systems (e.g., ISO 9001 and ISO 14001) allow for implementation and certification at the enterprise level. The "Central Office" concept, which allows a small group of employees to manage and facilitate the organization's energy management system (EnMS) at the enterprise level, was introduced within the ISO 50003 standard to provide guidance to ISO 50001 certification bodies.
Four industrial companies have partnered with the United States Department of Energy to pilot the enterprise-wide ISO 50001/SEP concept under the Better Buildings Superior Energy Performance (SEP) Enterprise-wide Accelerator. Each organization developed a Central Office to host their EnMS while implementing ISO 50001/SEP at multiple physically separated sites. The four corporate partners tailored their Central Office implementation model to meet their own specific circumstances and needs. This paper reviews the commonalities, differences, and benefits of each of these enterprise-wide implementation models, including organizational structures, Central Office staff responsibilities, and key strategies.
The cost savings and benefits of using the enterprise-wide approach were assessed, including the cost per site compared with that of a conventional, single-site ISO 50001/SEP implementation approach. This paper also discusses the drivers for the cost reductions realized through these enterprise-wide approaches.
The four partner companies worked with 30 total sites. On average, these 30 sites improved energy performance by 5% annually over their SEP achievement periods, saved more than $600,000 annually in energy costs and reduced implementation cost for ISO 50001 and SEP by $19,000 and 0.8 Full Time Equivalent × years (FTE-yr) of staff time per site. The results can inform other organizations seeking to implement enterprise-wide ISO 50001/SEP, as well as energy efficiency organizations seeking to promote wider adoption of ISO 50001 implementation.%I Lawrence Berkeley National Laboratory %C Berkeley %8 06/2017 %G eng %2 LBNL-2001089 %0 Journal Article %J Energy Policy %D 2017 %T Predicting the quantifiable impacts of ISO 50001 on climate change mitigation %A Aimee T. McKane %A Peter L. Therkelsen %A Anna Scodel %A Prakash Rao %A Arian Aghajanzadeh %A Simon Hirzel %A Ruiqin Zhang %A Richard Prem %A Alberto Fossa %A Ana M. Lazarevska %A Marco Matteini %A Bettina Schreck %A Fabian Allard %A Noé Villegal Alcántar %A Karel Steyn %A Ertaç Hürdoğan %A Thomas Björkman %A John O'Sullivan %X
Energy consumption in the industrial and commercial (service) sectors accounts for nearly 40% of global greenhouse gas emissions. Reducing this energy consumption will be critical for countries to achieve their national greenhouse gas reduction commitments. The ISO 50001-Energy management standard provides a continual improvement framework for organizations to reduce their consumption. Several national policies already support ISO 50001; however, there is no transparent, consistent process to estimate the potential impacts of its implementation.
This paper presents the ISO 50001 Impacts Methodology, an internationally-developed methodology to calculate these impacts at a national, regional, or global scale suitable for use by policymakers. The recently-formed ISO 50001 Global Impacts Research Network provides a forum for policymakers to refine and encourage use of the methodology.
Using this methodology, a scenario with 50% of projected global industrial and service sector energy consumption under ISO 50001 management by 2030 would generate cumulative primary energy savings of approximately 105 EJ, cost savings of nearly US $700 billion (discounted to 2016 net present value), and 6500 million metric tons (Mt) of avoided CO2 emissions. The avoided annual CO2 emissions in 2030 alone are equivalent to removing 210 million passenger vehicles from the road.%B Energy Policy %V 107 %P 278 - 288 %8 08/2017 %G eng %2 LBNL-2001076 %! Energy Policy %R 10.1016/j.enpol.2017.04.049 %0 Journal Article %J Building Simulation %D 2017 %T Smart Building Management vs. Intuitive Human Control — Lessons learnt from an office building in Hungary %A Zsofia Belafi %A Tianzhen Hong %A Andras Reith %K building operation %K building performance simulation %K case study %K Occupant Behaviour %K optimization %X
Smart building management and control are adopted nowadays to achieve zero-net energy use in buildings. However, without considering the human dimension, technologies alone do not necessarily guarantee high performance in buildings. An office building was designed and built according to state-of-the-art design and energy management principles in 2008. Despite the expectations of high performance, the owner was facing high utility bills and low user comfort in the building located in Budapest, Hungary. The objective of the project was to evaluate the energy performance and comfort indices of the building, to identify the causes of malfunction and to elaborate a comprehensive energy concept. Firstly, current building conditions and operation parameters were evaluated. Our investigation found that the state-of-the-art building management system was in good conditions but it was operated by building operators and occupants who are not aware of the building management practice. The energy consumption patterns of the building were simulated with energy modelling software. The baseline model was calibrated to annual measured energy consumption, using actual occupant behaviour and presence, based on results of self-reported surveys, occupancy sensors and fan-coil usage data. Realistic occupant behaviour models can capture diversity of occupant behaviour and better represent the real energy use of the building. This way our findings and the effect of our proposed improvements could be more reliable. As part of our final comprehensive energy concept, we proposed intervention measures that would increase indoor thermal comfort and decrease energy consumption of the building. A parametric study was carried out to evaluate and quantify energy, comfort and return on investment of each measure. It was found that in the best case the building could save 23% of annual energy use. Future work includes the follow-up of: occupant reactions to intervention measures, the realized energy savings, the measurement of occupant satisfaction and behavioural changes.%B Building Simulation %V 10 %P 811-828 %8 12/2017 %G eng %N 6 %R 10.1007/s12273-017-0361-4 %0 Journal Article %J Annual Review of Environment and Resources %D 2017 %T Technology and Engineering of the Water-Energy Nexus %A Prakash Rao %A Robert Kostecki %A Larry L. Dale %A Ashok J. Gadgil %K advanced wastewater treatment %K desalination %K thermoelectric cooling %K water and energy efficiency %K water-energy nexus %X
The global demand for water and energy is projected to grow, but there likely will be significant constraints in our ability to keep meeting it. These constraints will be imposed partly by the interdependence between water, energy, and climate change. If left unchecked, these connections can exacerbate water and energy shortages and aggravate climate change impacts: Energy is used to supply and treat water; moreover, emissions from energy generation contribute to climate change, which affects water supplies and increases the demand for energy to sustain Earth's growing population and economy. The linkage between water and energy can offer opportunities for better meeting expected demand while minimizing damage from shortages of either. This article focuses on the technological and engineering aspects of various connections in the water-energy nexus where advancements can enable greater supply of one or both. It also outlines the benefits and challenges associated with each connection.%B Annual Review of Environment and Resources %V 42 %P 407 - 437 %8 10/2017 %G eng %N 1 %! Annu. Rev. Environ. Resour. %R 10.1146/annurev-environ-102016-060959 %0 Report %D 2017 %T Verifying mixing in dilution tunnels: How to ensure cookstove emissions samples are unbiased %A Daniel L. Wilson %A Vi H. Rapp %A Julien J. Caubel %A Sharon S. Chen %A Ashok J. Gadgil %X
A well-mixed diluted sample is essential for unbiased measurement of cookstove emissions. Most cookstove testing labs employ a dilution tunnel, also referred to as a "duct," to mix clean dilution air with cookstove emissions before sampling. It is important that the emissions be well-mixed and unbiased at the sampling port so that instruments can take representative samples of the emission plume. Some groups have employed mixing baffles to ensure the gaseous and aerosol emissions from cookstoves are well-mixed before reaching the sampling location [2, 4]. The goal of these baffles is to to dilute and mix the emissions stream with the room air entering the fume hood by creating a local zone of high turbulence. However, potential drawbacks of mixing baffles include increased flow resistance (larger blowers needed for the same exhaust flow), nuisance cleaning of baffles as soot collects, and, importantly, the potential for loss of PM2.5 particles on the baffles themselves, thus biasing results.
A cookstove emission monitoring system with baffles will collect particles faster than the duct's walls alone. This is mostly driven by the available surface area for deposition by processes of Brownian diffusion (through the boundary layer) and turbophoresis (i.e. impaction). The greater the surface area available for diffusive and advection-driven deposition to occur, the greater the particle loss will be at the sampling port. As a layer of larger particle "fuzz" builds on the mixing baffles, even greater PM2.5 loss could occur. The micro structure of the deposited aerosol will lead to increased rates of particle loss by interception and a tendency for smaller particles to deposit due to impaction on small features of the micro structure. If the flow stream could be well-mixed without the need for baffles, these drawbacks could be avoided and the cookstove emissions sampling system would be more robust.%8 12/2017 %G eng %2 LBNL-2001088 %0 Report %D 2017 %T Xcel Energy – LBNL 'Beyond Widgets' Project Workstation Specific Lighting with Daylight Dimming Controls System Program Manual %A Cynthia Regnier %A Paul A. Mathew %A Alastair Robinson %A Jordan Shackelford %A Peter Schwartz %A Travis Walter %X
This program manual was developed through a U.S. Department of Energy project to develop streamlined utility program approaches to the deployment of integrated systems in commercial offices. Integrated systems present deep opportunities for energy savings, however by nature these systems have additional levels of complexity and effort required for their design and energy savings assessment, which create barriers for utility incentive programs to develop streamlined cost effective incentive programs to capture these savings. This project worked with Xcel Energy in Colorado and Minnesota to select an integrated system and develop a streamlined approach to its deployment for small and large commercial offices.
Xcel Energy worked with LBNL to select a workstation specific lighting system with daylight dimming controls, applied as a retrofit in commercial office spaces. Previous studies indicated a potential lighting annual energy savings of 28-63%, with an average of 47% for this system type, due to reduced fixture LPD and controls only, not including a full fixture replacement from a condition such as T8 to LED. Xcel also had a desire to incorporate this fixture replacement in their integrated system package, and as a result annual energy lighting savings are expected to be higher. FLEXLAB testing of the system for 500 lux minimum output conditions translated into a 94% annual energy savings for this system.
Market analysis was developed for large and medium commercial office buildings in Xcel's Minnesota and Colorado markets showing a potential for 48-295 and 120-672 GWh of energy savings potential for Colorado and Minnesota respectively. Total Resource Costs (TRC) vary by location and technology package used (enterprise versus non-enterprise lighting controls system), and vary from 0.29 to 1.27 and 0.06 and 0.44 for a Retrofit case, and 0.20 to 1.63 and 0.07 to 0.57 for a Replace on Burnout strategy for Colorado and Minnesota respectively. These results indicate good potential for demonstrating a strong technical and economic case for deployment of this system type in Xcel's Colorado territory, while deployment in the Minnesota market may be advisable as well as part of a portfolio of programs, or as an effort to help shift the market into integrated systems deployment in general. It should be noted that the cost of avoided energy in both markets is significantly low ($0.07/kWh for Minnesota, $0.08/kWh for Colorado), and these TRC values would not be representative of deployment potential in other markets with higher utility rates. In addition, installation costs used for these systems may decrease with time, further enhancing their return on investment.
This program manual documents candidate site criteria for selection to implement this system through a utility incentive program. The system was also configured and tested in LBNL's FLEXLAB™ (flexlab.lbl.gov) under conditions representing a range of implementations of the system including different tuned light output levels at the occupant's workstation (300 and 500 lux) and different light fixture types (LED pendant and troffer). The FLEXLAB testing demonstrated strong energy savings against the baseline case of a T-8 zonal lighting configuration typical for Xcel's office market, with 94% annual lighting energy savings during daylight hours (7am – 7pm), and ~87% annual energy savings overall all hours. These results validated the energy savings potential illustrated by earlier work, and also provided empirical data to develop a streamlined customer savings assessment methodology. This methodology assesses the annual energy savings potential from reduced installed LPD. A study was conducted to assess whether variances in workplane illuminance values, and LPD would change significantly for a range of occupant densities not tested in the FLEXLAB tests. The tested case was the 2015 International Building Code maximum occupant density of 100 gross sf/person. Simulation studies of a 150 gross sf/person condition did not result in a significant difference in LPD, while the illuminance minimums were still met in the space.
The FLEXLAB™ test data also validated that minimum light levels were achieved in the workplane and egress areas. Visual comfort performance was evaluated for the workstation specific lighting system tested in FLEXLAB through the use of High Dynamic Range imaging to evaluate Discomfort Glare Performance. The workstations specific lighting systems demonstrated good visual comfort performance consistent with that experienced with other lighting system types, over the seasonal variations studied, including summer, fall and low sun angle conditions in winter. Some periods of higher levels of DGP were documented, also consistent with other lighting systems deployment that did not employ shading to block direct sunlight into the work space. To ensure satisfactory DGP is experienced throughout the course of all times of day and seasons, the use of an adjustable shading system is required to block out direct solar radiation. A venetian blind system would be recommended in order to allow for direct sun angle to be controlled while still permitting daylighting in to benefit the space.
Implementation guidance is presented in this program manual to assist utility program managers in their design of incentive programs and educate customers on key aspects of the system to focus on in commissioning and operations to ensure that lighting savings are realized. These include aspects such as a requirement for a commissioned lighting system that tunes light output levels to desired lux levels at the workplane, and verification that daylight dimming controls features are enabled and perform as desired.
Overall, workstation specific lighting systems with daylight dimming controls present a very strong potential for cost effective lighting energy savings, as demonstrated by the FLEXLAB test results and previous case studies. Further energy savings may be realized from the use of fixture-specific occupancy sensors as well, although this approach was not considered in this study.%G eng %2 2001161 %0 Report %D 2016 %T Accelerating Energy Efficiency in Indian Data Centers: Final Report for Phase I Activities %A Suprotim Ganguly %A Sanyukta Raje %A Satish Kumar %A Dale A. Sartor %A Steve E. Greenberg %8 01/2016 %U https://datacenters.lbl.gov/resources/accelerating-energy-efficiency-indian %2 LBNL-1005085 %0 Conference Paper %B Energy Efficiency in Motor Driven Systems, 2015 %D 2016 %T Assessing Energy Efficiency Opportunities in US Industrial and Commercial Building Motor Systems %A Prakash Rao %A Paul Sheaffer %A Aimee T. McKane %A Paul Scheihing %K Assessing energy efficiency %K commercial building motor systems %K energy efficiency %X
In 2002, the United States Department of Energy (USDOE) published an energy efficiency assessment of U.S. industrial sector motor systems titled United States Industrial Electric Motor Systems Market Opportunities Assessment. The assessment advanced motor system efficiency by providing a greater understanding of the energy consumption, use characteristics, and energy efficiency improvement potential of industrial sector motor systems in the U.S. Since 2002, regulations such as Minimum Energy Performance Standards, cost reductions for motor system components such as variable frequency drives, systemintegrated motor-driven equipment, and awareness programs for motor system energy efficiency have changed the landscape of U.S. motor system energy consumption. To capture the new landscape, the USDOE has initiated a three-year Motor System Market Assessment (MSMA), led by Lawrence Berkeley National Laboratory (LBNL). The MSMA will assess the energy consumption, operational and maintenance characteristics, and efficiency improvement opportunity of U.S. industrial sector and commercial building motor systems. As part of the MSMA, a significant effort is currently underway to conduct field assessments of motor systems from a sample of facilities representative of U.S. commercial and industrial motor system energy consumption. The Field Assessment Plan used for these assessments builds on recent LBNL research presented at EEMODS 2011 and EEMODS 2013 using methods for characterizing and determining regional motor system energy efficiency opportunities. This paper provides an update on the development and progress of the MSMA, focusing on the Field Assessment Plan and the framework for assessing the global supply chain for emerging motors and drive technologies.%B Energy Efficiency in Motor Driven Systems, 2015 %8 03/2016 %2 LBNL-1005023 %0 Journal Article %J ACEEE %D 2016 %T Beyond Widgets – Systems Incentive Programs for Utilities %A Cynthia Regnier %A Paul A. Mathew %A Alastair Robinson %A Peter Schwartz %A Travis Walter %K Building Technology and Urban Systems Division %K Commercial Building Systems %K External %K Whole Building Systems Department %X
Utility incentive programs remain one of the most significant means of deploying commercialized, but underutilized building technologies to scale. However, these programs have been largely limited to component-based products (e.g., lamps, RTUs). While some utilities do provide 'custom' incentive programs with whole building and system level technical assistance, these programs require deeper levels of analysis, resulting in higher program costs. This results in custom programs being restricted to utilities with greater resources, and are typically applied mainly to large or energy-intensive facilities, leaving much of the market without cost effective access and incentives for these solutions. In addition, with increasingly stringent energy codes, cost effective component-based solutions that achieve significant savings are dwindling.
Building systems (e.g., integrated façade, HVAC and/or lighting solutions) can deliver higher savings that translate into large sector-wide savings if deployed at the scale of these programs. However, systems application poses a number of challenges – baseline energy use must be defined and measured; the metrics for energy and performance must be defined and tested against; in addition, system savings must be validated under well understood conditions.
This paper presents a sample of findings of a project to develop validated utility incentive program packages for three specific integrated building systems, in collaboration with Xcel Energy (CO, MN), ComEd, and a consortium of California Public Owned Utilities (CA POUs) (Northern California Power Agency (NCPA) and the Southern California Public Power Authority (SCPPA)). These program packages consist of system specifications, system performance, M&V protocols, streamlined assessment methods, market assessment and implementation guidance.%B ACEEE %2 LBNL-1006195 %0 Conference Paper %B 2016 ACEEE Summer Study on Energy Efficiency in Buildings %D 2016 %T Direct Current as an Integrating Platform for ZNE Buildings with EVs and Storage: DC Direct Systems – A Bridge to a Low Carbon Future? %A Karl Johnson %A Vagelis Vossos %A Margarita Kloss %A Gerald Robinson %A Richard E. Brown %X
Cost effective zero net energy (ZNE) schemes exist for many types of residential and commercial buildings. Yet, today's alternating current (AC) based ZNE designs may be as much as 10% to 20% less efficient, more costly, and more complicated than a design based on direct current (DC) technologies. An increasing number of research organizations and manufacturers are just starting the process of developing products and conducting research and development (R&D) efforts. These early R&D efforts indicate that the use of DC technologies may deliver many energy and non-energy benefits relative to AC-based typologies. DC ZNE schemes may provide for an ideal integrating platform for natively DC-based onsite generation, storage, electric vehicle (EV) charging and end-use loads. Emerging empirical data suggest that DC end-use appliances are more efficient, simpler, more durable, and lower cost. DC technologies appear to provide ratepayers a lower cost pathway to achieve resilient ZNE buildings, and simultaneously yield a plethora of benefits.
This paper draws from the current research effort entitled "Direct Current as an Integrating and Enabling Platform," co-led by the Lawrence Berkeley National Laboratory (LBNL), the California Institute for Energy and the Environment (CIEE), the Electric Power Research Institute (EPRI) and funded under the California Energy Commission's Energy Program Investment Charge (CEC EPIC). The first phase of this EPIC research is focused on assembling and summarizing known global performance information on DC and DC-AC hybrid end-use appliances and power systems. This paper summarizes the information and insights gained from this research effort.%B 2016 ACEEE Summer Study on Energy Efficiency in Buildings %8 08/2016 %G eng %2 LBNL-2001069 %0 Conference Paper %B ACEEE 2016 Summer Study on Energy Efficiency in Buildings %D 2016 %T Direct Current as an Integrating Platform for ZNE Buildings with EVs and Storage: DC Direct Systems - A Bridge to a Low Carbon Future %A Karl Johnson %A Vagelis Vossos %A Margarita Kloss %A Gerald Robinson %A Richard E. Brown %X
Cost effective zero net energy (ZNE) schemes exist for many types of residential and commercial buildings. Yet, today's alternating current (AC) based ZNE designs may be as much as 10% to 20% less efficient, more costly, and more complicated than a design based on direct current (DC) technologies. An increasing number of research organizations and manufacturers are just starting the process of developing products and conducting research and development (R&D) efforts. These early R&D efforts indicate that the use of DC technologies may deliver many energy and non-energy benefits relative to AC-based typologies. DC ZNE schemes may provide for an ideal integrating platform for natively DC-based onsite generation, storage, electric vehicle (EV) charging and end-use loads. Emerging empirical data suggest that DC end-use appliances are more efficient, simpler, more durable, and lower cost. DC technologies appear to provide ratepayers a lower cost pathway to achieve resilient ZNE buildings, and simultaneously yield a plethora of benefits.
This paper draws from the current research effort entitled "Direct Current as an Integrating and Enabling Platform," co-led by the Lawrence Berkeley National Laboratory (LBNL), the California Institute for Energy and the Environment (CIEE), the Electric Power Research Institute (EPRI) and funded under the California Energy Commission's Energy Program Investment Charge (CEC EPIC). The first phase of this EPIC research is focused on assembling and summarizing known global performance information on DC and DC-AC hybrid end-use appliances and power systems. This paper summarizes the information and insights gained from this research effort.%B ACEEE 2016 Summer Study on Energy Efficiency in Buildings %C Pacific Grove, California %8 08/2016 %U http://aceee.org/files/proceedings/2016/data/papers/10_780.pdf %2 LBNL-100705 %0 Report %D 2016 %T Global Impact Estimation of ISO 50001 Energy Management System for Industrial and Service Sectors %A Arian Aghajanzadeh %A Peter L. Therkelsen %A Prakash Rao %A Aimee T. McKane %I Lawrence Berkeley National Laboratory %C Berkeley %8 08/2016 %2 LBNL-1006337 %0 Report %D 2016 %T The ISO 50001 Impact Estimator Tool (IET 50001 V1.1.4) - User Guide and Introduction to the ISO 50001 Impacts Methodology %A Peter L. Therkelsen %A Prakash Rao %A Arian Aghajanzadeh %A Aimee T. McKane %I Lawrence Berkeley National Laboratory %C Berkeley %8 08/2016 %2 LBNL-1006338 %0 Report %D 2016 %T Next-Generation Factory-Produced Cool Asphalt Shingles: Phase 1 Final Report %A Ronnen M. Levinson %A Sharon S. Chen %A George A. Ban-Weiss %A Haley E. Gilbert %A Paul H. Berdahl %A Pablo J. Rosado %A Hugo Destaillats %A Mohamad Sleiman %A Thomas W. Kirchstetter %X
As the least expensive category of high-slope roofing in the U.S., shingles are found on the roofs of about 80% of U.S. homes, and constitute about 80% (by product area) of this market. Shingles are also among the least reflective high-slope roofing products, with few cool options on the market. The widespread use of cool roofs in the two warmest U.S. climate zones could reduce annual residential cooling energy use in these zones by over 7%. This project targets the development of high-performance cool shingles with initial solar reflectance at least 0.40 and a cost premium not exceeding US$0.50/ft2.
Phase 1 of the current study explored three approaches to increasing shingle reflectance. Method A replaces dark bare granules by white bare granules to enhance the near-infrared reflectance attained with cool pigments. Method B applies a white basecoat and a cool-color topcoat to a shingle surfaced with dark bare granules. Method C applies a visually clear, NIR-reflecting surface treatment to a conventionally colored shingle. Method A was the most successful, but our investigation of Method B identified roller coating as a promising top-coating technique, and our study of Method C developed a novel approach based on a nanowire mesh.
Method A yielded red, green, brown, and black faux shingles with solar reflectance up to 0.39 with volumetric coloration. Since the base material is white, these reflectances can readily be increased by using less pigment. The expected cost premium for Method A shingles is less than our target limit of $0.50/ft2, and would represent less than a 10% increase in the installed cost of a shingle roof. Using inexpensive but cool (spectrally selective) iron oxide pigments to volumetrically color white limestone synthesized from sequestered carbon and seawater appears to offer high albedo at low cost.
In Phase 2, we plan to refine the cool shingle prototypes, manufacture cool granules, and manufacture and market high- performance cool shingles.%8 11/2016 %2 LBNL-2001007 %0 Journal Article %J Environmental Science & Technology %D 2016 %T Reducing Ultrafine Particle Emissions Using Air Injection in Wood-Burning Cookstoves %A Vi H. Rapp %A Julien J. Caubel %A Daniel L. Wilson %A Ashok J. Gadgil %X
In order to address the health risks and climate impacts associated with pollution from cooking on biomass fires, researchers have focused on designing new cookstoves that improve cooking performance and reduce harmful emissions, specifically particulate matter (PM). One method for improving cooking performance and reducing emissions is using air injection to increase turbulence of unburned gases in the combustion zone. Although air injection reduces total PM mass emissions, the effect on PM size distribution and number concentration has not been thoroughly investigated. Using two new wood-burning cookstove designs from Lawrence Berkeley National Laboratory, this research explores the effect of air injection on cooking performance, PM and gaseous emissions, and PM size distribution and number concentration. Both cookstoves were created using the Berkeley–Darfur Stove as the base platform to isolate the effects of air injection. The thermal performance, gaseous emissions, PM mass emissions, and particle concentrations (ranging from 5 nm to 10 μm in diameter) of the cookstoves were measured during multiple high-power cooking tests. The results indicate that air injection improves cookstove performance and reduces total PM mass but increases total ultrafine (less than 100 nm in diameter) PM concentration over the course of high-power cooking.%B Environmental Science & Technology %V 50 %P 8368-8374 %8 06/2016 %2 LBNL-1006082 %& 8368 %R 10.1021/acs.est.6b01333 %0 Report %D 2016 %T Volume 1: Survey of Available Information in Support of the Energy-Water Bandwidth Study of Desalination Systems %A Prakash Rao %A Arian Aghajanzadeh %A Paul Sheaffer %A William R. Morrow III %A Sabine Brueske %A Caroline Dollinger %A Kevin Price %A Prateeti Sarker %A Nicholas Ward %A Joe Cresko %I Lawrence Berkeley National Laboratory %8 10/2016 %2 LBNL-1006424 %0 Generic %D 2015 %T Achieving a Net Zero Energy Retrofit – in a humid, temperate climate – lessons from the University of Hawai'i at Mānoa %A Cynthia Regnier %A Ari Harding %A Alastair Robinson %8 07/2015 %2 LBNL-189802 %0 Report %D 2015 %T Assessment of Literature Related to Combustion Appliance Venting Systems %A Vi H. Rapp %A Brett C. Singer %A J. Chris Stratton %A Craig P. Wray %A Brennan Less %X
In many residential building retrofit programs, air tightening to increase energy efficiency is constrained by concerns about related impacts on the safety of naturally vented combustion appliances. Tighter housing units more readily depressurize when exhaust equipment is operated, making combustion appliances more prone to backdraft or spillage. Several test methods purportedly assess the potential for depressurization-induced backdrafting and spillage, but these tests are not robustly reliable and repeatable predictors of venting performance, in part because they do not fully capture weather effects on venting performance. The purpose of this literature review is to investigate combustion safety diagnostics in existing codes, standards, and guidelines related to combustion appliances. This review summarizes existing combustion safety test methods, evaluations of these test methods, and also discusses research related to wind effects and the simulation of vent system performance. Current codes and standards related to combustion appliance installation provide little information on assessing backdrafting or spillage potential. A substantial amount of research has been conducted to assess combustion appliance backdrafting and spillage test methods, but primarily focuses on comparing short-term (stress) induced tests and monitoring results. Monitoring, typically performed over one week, indicated that combinations of environmental and house operation characteristics most conducive to combustion spillage were rare. Research, to an extent, has assessed existing combustion safety diagnostics for house depressurization, but the objectives of the diagnostics, both stress and monitoring, are not clearly defined. More research is also needed to quantify the frequency of test "failure" occurrence throughout the building stock and assess the statistical effects of weather (especially wind) on house depressurization and in turn on combustion appliance venting. Incorporating weather variations and house ventilation system characteristics in existing simulation software may assist such analyses and with developing a more reliable diagnostic for use on-site.
Revision of LBNL-5798E Original Release June 2012%8 06/2012 %2 LBNL-176805 %0 Generic %D 2015 %T The Business of High Performance: The USC Darla Moore School of Business %A Cynthia Regnier %A Kevin Settlemyre %K High performance buildings %8 10/2015 %2 LBNL-1003926 %0 Conference Proceedings %B BS2015: 14th Conference of International Building Performance Simulation Association %D 2015 %T CLIMATE-SPECIFIC MODELING AND ANALYSIS FOR BEST-PRACTICE INDIAN OFFICE BUILDINGS %A Reshma Singh %A Baptiste Ravache %A Spencer M. Dutton %K Climate specific building energy models %K india %X
This paper describes the methodology and results of building energy modeling to validate and quantify the energy savings from conservation measures in medium-sized office buildings in four different climate zones in India. We present the different energy measures and their expected and simulated performances and discuss the results and the influence of climate.%B BS2015: 14th Conference of International Building Performance Simulation Association %C Hyderabad, India %8 12/2015 %G eng %U http://www.ibpsa.org/proceedings/BS2015/p2714.pdf %0 Generic %D 2015 %T Controlling Energy Performance on the Big Stage — The New York Times Company %A Kevin Settlemyre %A Cynthia Regnier %X
The Times partnered with the U.S. Department of Energy (DOE) as part of DOE's Commercial Building Partnerships (CBP) Program to develop a post-occupancy evaluation (POE) of three EEMs that were implemented during the construction of The Times building between 2004-2006. With aggressive goals to reduce energy use and carbon emissions at a national level, one strategy of the US Department of Energy is looking to exemplary buildings that have already invested in new approaches to achieving the energy performance goals that are now needed at scale. The Times building incorporated a number of innovative technologies, systems and processes that make their project a model for widespread replication in new and existing buildings. The measured results from the post occupancy evaluation study, the tools and processes developed, and continuous improvements in the performance and cost of the systems studied suggest that these savings are scalable and replicable in a wide range of commercial buildings nationwide%I Lawrence Berkeley National Laboratory %C Berkeley, CA %8 08/2015 %2 LBNL-1003827 %0 Journal Article %J Environmental Science & Technology %D 2015 %T Cool Roofs in Guangzhou, China: Outdoor Air Temperature Reductions during Heat Waves and Typical Summer Conditions %A Meichun Cao %A Pablo J. Rosado %A Zhaohui Lin %A Ronnen M. Levinson %A Dev Millstein %X
In this paper, we simulate temperature reductions during heat-wave events and during typical summer conditions from the installation of highly reflective "cool" roofs in the Chinese megacity of Guangzhou. We simulate temperature reductions during six of the strongest historical heat-wave events over the past decade, finding average urban midday temperature reductions of 1.2 °C. In comparison, we simulate 25 typical summer weeks between 2004 and 2008, finding average urban midday temperature reductions of 0.8 °C, indicating that air temperature sensitivity to urban albedo in Guangzhou varies with meteorological conditions. We find that roughly three-fourths of the variance in air temperature reductions across all episodes can be accounted for by a linear regression, including only three basic properties related to the meteorological conditions: mean daytime temperature, humidity, and ventilation to the greater Guangzhou urban area. While these results highlight the potential for cool roofs to mitigate peak temperatures during heat waves, the temperature reductions reported here are based on the upper bound case, which increases albedos of all roofs (but does not modify road albedo or wall albedo).%B Environmental Science & Technology %V 49 %P 14672 - 14679 %8 12/2015 %G eng %N 24 %! Environ. Sci. Technol. %R 10.1021/acs.est.5b04886 %0 Journal Article %J Energy and Buildings %D 2015 %T Data Analysis and Stochastic Modeling of Lighting Energy Use in Large Office Buildings in China %A Xin Zhou %A Da Yan %A Tianzhen Hong %A Xiaoxin Ren %K building simulation %K energy use %K Lighting modeling %K occupant behavior %K office buildings %K Poisson distribution %K stochastic modeling %X
Lighting consumes about 20% to 40% of the total electricity use in large office buildings in China. Commonly in building simulations, static time schedules for typical weekdays, weekends and holidays are assumed to represent the dynamics of lighting energy use in buildings. This approach does not address the stochastic nature of lighting energy use, which can be influenced by occupant behavior in buildings. This study analyzes the main characteristics of lighting energy use over various timescales, based on the statistical analysis of measured lighting energy use data from 15 large office buildings in Beijing and Hong Kong. It was found that in these large office buildings, the 24-hourly variation in lighting energy use was mainly driven by the schedules of the building occupants. Outdoor illuminance levels had little impact on lighting energy use due to the lack of automatic daylighting controls (an effective retrofit measure to reduce lighting energy use) and the relatively small perimeter area exposed to natural daylight. A stochastic lighting energy use model for large office buildings was further developed to represent diverse occupant activities, at six different time periods throughout a day, and also the annual distribution of lighting power across these periods. The model was verified using measured lighting energy use from the 15 buildings. The developed stochastic lighting model can generate more accurate lighting schedules for use in building energy simulations, improving the simulation accuracy of lighting energy use in real buildings.%B Energy and Buildings %V 86 %P 275-287 %8 01/2015 %2 LBNL-180389 %R 10.1016/j.enbuild.2014.09.071 %0 Journal Article %J Building and Environment %D 2015 %T Data Mining of Space Heating System Performance in Affordable Housing %A Xiaoxin Ren %A Da Yan %A Tianzhen Hong %K affordable housing %K building simulation %K clustering %K data mining %K decision tree %K occupant behavior %K space heating %X
The space heating in residential buildings accounts for a considerable amount of the primary energy use. Therefore, understanding the operation and performance of space heating systems becomes crucial in improving occupant comfort while reducing energy use. This study investigated the behavior of occupants adjusting their thermostat settings and heating system operations in a 62-unit affordable housing complex in Revere, Massachusetts, USA. The data mining methods, including clustering approach and decision trees, were used to ascertain occupant behavior patterns. Data tabulating ON/OFF space heating states was assessed, to provide a better understanding of the intermittent operation of space heating systems in terms of system cycling frequency and the duration of each operation. The decision tree was used to verify the link between room temperature settings, house and heating system characteristics and the heating energy use. The results suggest that the majority of apartments show fairly constant room temperature profiles with limited variations during a day or between weekday and weekend. Data clustering results revealed six typical patterns of room temperature profiles during the heating season. Space heating systems cycled more frequently than anticipated due to a tight range of room thermostat settings and potentially oversized heating capacities. The results from this study affirm data mining techniques are an effective method to analyze large datasets and extract hidden patterns to inform design and improve operations.%B Building and Environment %V 89 %P 1-13 %8 07/2015 %2 LBNL-180239 %R 10.1016/j.buildenv.2015.02.009 %0 Conference Paper %B 2015 American Council for an Energy-Efficient Economy Summer Study on Energy Efficiency in Industry %D 2015 %T Development of an Enhanced Payback Function for the Superior Energy Performance Program %A Peter L. Therkelsen %A Prakash Rao %A Aimee T. McKane %A Ridah Sabouni %A Yannick Tamm %A Paul Scheihing %X
The U.S. DOE Superior Energy Performance (SEP) program provides recognition to industrial and commercial facilities that achieve certification to the ISO 50001 energy management system standard and third party verification of energy performance improvements. Over 50 industrial facilities are participating and 28 facilities have been certified in the SEP program. These facilities find value in the robust, data driven energy performance improvement result that the SEP program delivers. Previous analysis of SEP certified facility data demonstrated the cost effectiveness of SEP and identified internal staff time to be the largest cost component related to SEP implementation and certification. This paper analyzes previously reported and newly collected data of costs and benefits associated with the implementation of an ISO 50001 and SEP certification. By disaggregating "sunk energy management system (EnMS) labor costs", this analysis results in a more accurate and detailed understanding of the costs and benefits of SEP participation. SEP is shown to significantly improve and sustain energy performance and energy cost savings, resulting in a highly attractive return on investment. To illustrate these results, a payback function has been developed and is presented. On average facilities with annual energy spend greater than $2M can expect to implement SEP with a payback of less than 1.5 years. Finally, this paper also observes and details decreasing facility costs associated with implementing ISO 50001 and certifying to the SEP program, as the program has improved from pilot, to demonstration, to full launch%B 2015 American Council for an Energy-Efficient Economy Summer Study on Energy Efficiency in Industry %C Buffalo, NY %8 08/2015 %2 LBNL-190883 %0 Conference Paper %B 2015 ACEEE Summer Study on Energy Efficiency in Industry %D 2015 %T Energy Savings from Industrial Water Reductions %A Prakash Rao %A Aimee T. McKane %A Andre de Fontaine %X
Although it is widely recognized that reducing freshwater consumption is of critical importance, generating interest in industrial water reduction programs can be hindered for a variety of reasons. These include the low cost of water, greater focus on water use in other sectors such as the agriculture and residential sectors, high levels of unbilled and/or unregulated self-supplied water use in industry, and lack of water metering and tracking capabilities at industrial facilities. However, there are many additional components to the resource savings associated with reducing site water use beyond the water savings alone, such as reductions in energy consumption, greenhouse gas emissions, treatment chemicals, and impact on the local watershed. Understanding and quantifying these additional resource savings can expand the community of businesses, NGOs, government agencies, and researchers with a vested interest in water reduction.
This paper will develop a methodology for evaluating the embedded energy consumption associated with water use at an industrial facility. The methodology developed will use available data and references to evaluate the energy consumption associated with water supply and wastewater treatment outside of a facility's fence line for various water sources. It will also include a framework for evaluating the energy consumption associated with water use within a facility's fence line. The methodology will develop a more complete picture of the total resource savings associated with water reduction efforts and allow industrial water reduction programs to assess the energy and CO2 savings associated with their efforts.%B 2015 ACEEE Summer Study on Energy Efficiency in Industry %C Buffalo, NY %8 08/2015 %2 LBNL-190943 %0 Government Document %D 2015 %T Green, Clean, & Mean: Pushing the Energy Envelope in Tech Industry Buildings %A Evan Mills %A Jessica Granderson %A Wanyu R. Chan %A Richard C. Diamond %A Philip Haves %A Bruce Nordman %A Paul A. Mathew %A Mary Ann Piette %A Gerald Robinson %A Stephen E. Selkowitz %X
When it comes to innovation in energy and building performance, one can expect leading-edge activity from the technology sector. As front-line innovators in design, materials science, and information management, developing and operating high-performance buildings is a natural extension of their core business.
The energy choices made by technology companies have broad importance given their influence on society at large as well as the extent of their own energy footprint. Microsoft, for example, has approximately 250 facilities around the world (30 million square feet of floor area), with significant aggregate energy use of approximately 4 million kilowatt-hours per day.
There is a degree of existing documentation of efforts to design, build, and operate facilities in the technology sector. However, the material is fragmented and typically looks only at a single company, or discrete projects within a company.Yet, there is no single resource for corporate planners and decision makers that takes stock of the opportunities and documents sector-specific case studies in a structured manner. This report seeks to fill that gap, doing so through a combination of generalized technology assessments ("Key Strategies") and case studies ("Flagship Projects").%I Lawrence Berkeley National Laboratory %8 05/2015 %2 LBNL-1005070E %0 Generic %D 2015 %T A New Campus Built on Efficiency %A Ari Harding %A Andrea C. Mercado %A Cynthia Regnier %X
The University of California (UC), Merced partnered with the U.S. Department of Energy (DOE) to develop and implement solutions to reduce energy consumption by as part of DOE's Commercial Buildings Partnerships (CBP) Program. Lawrence Berkeley National Laboratory (LBNL) provided technical expertise in support of this DOE program. This case study reports on the process and outcome of this project including the achieved savings from design improvements for the campus.
The intent of the project was to retrofit the Science & Engineering (S&E) building and the central plant at UC Merced to achieve up to 30% energy reduction. The anticipated savings from these retrofits represented about 17% of whole-campus energy use. If achieved, the savings contribution from the CBP project would have brought overall campus performance to 56% of the 1999 UC/CSU benchmark performance for their portfolio of buildings. However, the final design that moved forward as part of the CBP program only included the retrofit measures for the S&E building.%8 08/2015 %2 LBNL-189311 %0 Conference Paper %B 2015 ACEEE Summer Study on Energy Efficiency in Industry %D 2015 %T Promoting Strong ISO 50001 Outcomes with Supportive National Infrastructure %A Graziella Siciliano %A Aimee T. McKane %A Pamela de los Reyes %K ISO 50001 %X
The ISO 50001 standard is a key mechanism for reducing greenhouse gas emissions and improving energy efficiency globally. An increasing number of companies are seeking certification, creating the need for personnel that are competent to conduct ISO 50001 certification audits. The growth of ISO 50001 is expected to accelerate as more companies integrate ISO 50001 into their corporate sustainability strategies and supplier requirements. Robust implementation of ISO 50001 represents an important tool for countries with climate change mitigation goals. Because of its dual focus on continual improvement of an organization's energy management system (EnMS) and its energy performance improvement, ISO 50001 requires skills of both implementers and certification auditors that are not wellsupported by current credentials and training. This paper describes an effort to address skill gaps of certification auditors, a critical factor to ensure that ISO 50001 implementations are robust and result in continued energy performance improvement. A collaboration of governments through the Energy Management Working Group (EMWG), formerly under Global Superior Energy Performance (GSEP), has formed to build workforce capacity for ISO 50001 certification audits. The EMWG is leading the development of an internationally-relevant certification scheme for ISO 50001 Lead Auditor that meets requirements for ISO/IEC 17024 accreditation and ISO 50003 for defining ISO 50001 Lead Auditor competency. Wider availability of competent ISO 50001 Lead Auditors will ultimately increase the impact and market value of ISO 50001 certification and improve consistency of ISO 50001 certification outcomes by establishing a standardized and high level of knowledge and skills globally.%B 2015 ACEEE Summer Study on Energy Efficiency in Industry %C Buffalo, NY %8 08/2015 %2 LBNL-188776 %0 Report %D 2015 %T Residential Pre-Cooling: Mechanical Cooling and Air-Side Economizers %A William J. N. Turner %A Iain S. Walker %A Jordan Roux %K Air-Side Economizer %K Mechanical Cooling %K Night Ventilation %K pre-cooling %K Ventilation Cooling %X
This study used an advanced airflow, energy and humidity modeling tool to evaluate residential air-side economizers and mechanical pre-cooling strategies using the air conditioner, in all US DOE Climate Zones for a typical new home with ASHRAE Standard 62.2 compliant ventilation. A residential air-side economizer is a large supply fan used for night ventilation. Mechanical pre-cooling used the building air conditioner operating at lower than usual set before the peak demand period. The simulations were performed for a full year using one-minute time steps to allow for scheduling of ventilation systems and to account for interactions between ventilation and HVAC systems. The short time steps also allow for more precise evaluation of HVAC system cycling operation. The results showed that a residential economizer can save large quantities (more than 2000 kWh/year) of cooling energy – in some cases the energy savings offset all of the mechanical ventilation related energy use. Using a high performance Brushless Permanent Magnet (BPM) air handler in the HVAC system saved an additional 12% of cooling energy compared to more typical Permanent Split Capacitor (PSC) air handlers. However, economizers may cause problems with excess humidity in climate zones 2A and 3A (Houston and Memphis) due to increases in indoor humidity. The economizer was most effective in the hot and dry Climate Zones 2B, 3B (Phoenix, El Paso) and the marine Climate Zone 3C (San Francisco). There were less significant, but still desirable, energy savings in mixed temperature Climate Zones 4A, B & C (Baltimore, Albuquerque and Salem).
The effectiveness of pre-cooling is highly dependent on climate zone and the selected pre-cooling strategy. In this study the pre-cooling strategies included two levels of temperature depression: 22.2° and 23.3°C and pre-cooling times of 8, 5 and 3 hours. The results showed the expected tradeoff between peak savings and increased energy use. In looking to maximize peak energy savings and minimize the extra cooling energy used, our results showed that the high cooling climates (zones 1A-3B) gave the best results for the shortest time and least temperature depression. Climates with less cooling showed better results for pre-cooling with the least temperature depression. Climate Zones 3C and 8 showed no advantage with pre-cooling strategies due to near-zero air conditioning loads. One caveat with the pre-cooling recommendations is that they were for a lightweight wood frame construction and may change for heavier brick/block structures not included in this study.%8 09/2015 %2 LBNL-180960 %0 Journal Article %J Indoor Air %D 2015 %T Results of the California Healthy Homes Indoor Air Quality Study of 2011-2013: Impact of Natural Gas Appliances on Air Pollutant Concentrations %A Nasim A. Mullen %A Jina Li %A Marion L. Russell %A Michael Spears %A Brennan Less %A Brett C. Singer %K carbon monoxide %K Cooking %K formaldehyde %K Kitchen ventilation %K Natural gas appliances %K nitrogen dioxide %X
This study was conducted to assess the current impact of natural gas appliances on air quality in California homes. Data were collected via telephone interviews and measurements inside and outside of 352 homes. Passive samplers measured time-resolved CO and time-integrated NOX, NO2, formaldehyde, and acetaldehyde over ~6-day periods in November 2011 – April 2012 and October 2012 – March 2013. The fraction of indoor NOX and NO2 attributable to indoor sources was estimated. NOX, NO2, and highest 1-h CO were higher in homes that cooked with gas and increased with amount of gas cooking. NOX and NO2 were higher in homes with cooktop pilot burners, relative to gas cooking without pilots. Homes with a pilot burner on a floor or wall furnace had higher kitchen and bedroom NOX and NO2compared to homes without a furnace pilot. When scaled to account for varying home size and mixing volume, indoor-attributed bedroom and kitchen NOX and kitchen NO2 were not higher in homes with wall or floor furnace pilot burners, although bedroom NO2 was higher. In homes that cooked 4 h or more with gas, self-reported use of kitchen exhaust was associated with lower NOX, NO2, and highest 1-h CO. Gas appliances were not associated with higher concentrations of formaldehyde or acetaldehyde.%B Indoor Air %8 03/2015 %R 10.1111/ina.12190 %0 Journal Article %J Urban Climate %D 2015 %T A Simple Tool for Estimating City-Wide Annual Electrical Energy Savings from Cooler Surfaces %A Melvin Pomerantz %A Pablo J. Rosado %A Ronnen M. Levinson %K albedo %K Cool Pavements %K Cool surface %K Electrical energy saving %K pavements %K urban heat island %K Urban heat island mitigation %X
We present a simple method to estimate the maximum possible electrical energy saving that might be achieved by increasing the albedo of surfaces in a large city. We restrict this to the "indirect effect", the cooling of outside air that lessens the demand for air conditioning (AC). Given the power demand of the electric utilities and data about the city, we can use a single linear equation to estimate the maximum savings. For example, the result for an albedo change of 0.2 of pavements in a typical warm city in California, such as Sacramento, is that the saving is less than about 2 kWh per m2 per year. This may help decision makers choose which heat island mitigation techniques are economical from an energy-saving perspective.%B Urban Climate %V 14 %P 315 - 325 %8 12/2015 %G eng %N 2 %2 LBNL-184804 %! Urban Climate %R 10.1016/j.uclim.2015.05.007 %0 Journal Article %J Solar Energy Materials and Solar Cells %D 2015 %T Soiling of building envelope surfaces and its effect on solar reflectance – Part III: Interlaboratory study of an accelerated aging method for roofing materials %A Mohamad Sleiman %A Sharon S. Chen %A Haley E. Gilbert %A Thomas W. Kirchstetter %A Paul H. Berdahl %A Erica Bibian %A Laura S. Bruckman %A Dominic Cremona %A Roger H. French %A Devin A. Gordon %A Marco Emiliani %A Justin Kable %A Liyan Ma %A Milena Martarelli %A Riccardo Paolini %A Matthew Prestia %A John Renowden %A Gian Marco Revel %A Olivier Rosseler %A Ming Shiao %A Giancarolo Terraneo %A Tammy Yang %A Lingtao Yu %A Michele Zinzi %A Hashem Akbari %A Ronnen M. Levinson %A Hugo Destaillats %K Aging %K cool roofs %K Interlaboratory study %K Soiling %K Solar reflectance %K thermal emittance %K Weathering %X
A laboratory method to simulate natural exposure of roofing materials has been reported in a companion article. In the current article, we describe the results of an international, nine-participant interlaboratory study (ILS) conducted in accordance with ASTM Standard E691-09 to establish the precision and reproducibility of this protocol. The accelerated soiling and weathering method was applied four times by each laboratory to replicate coupons of 12 products representing a wide variety of roofing categories (single-ply membrane, factory-applied coating (on metal), bare metal, field-applied coating, asphalt shingle, modified-bitumen cap sheet, clay tile, and concrete tile). Participants reported initial and laboratory-aged values of solar reflectance and thermal emittance. Measured solar reflectances were consistent within and across eight of the nine participating laboratories. Measured thermal emittances reported by six participants exhibited comparable consistency. For solar reflectance, the accelerated aging method is both repeatable and reproducible within an acceptable range of standard deviations: the repeatability standard deviation sr ranged from 0.008 to 0.015 (relative standard deviation of 1.2–2.1%) and the reproducibility standard deviation sR ranged from 0.022 to 0.036 (relative standard deviation of 3.2–5.8%). The ILS confirmed that the accelerated aging method can be reproduced by multiple independent laboratories with acceptable precision. This study supports the adoption of the accelerated aging practice to speed the evaluation and performance rating of new cool roofing materials.%B Solar Energy Materials and Solar Cells %V 143 %P 581-590 %8 12/2015 %R 10.1016/j.solmat.2015.07.031 %0 Report %D 2015 %T Wireless Advanced Lighting Controls Retrofit Demonstration %A Joy Wei %A Francis M. Rubinstein %A Jordan Shackelford %A Alastair Robinson %X
Awareness of the economic costs and environmental consequences of electric energy use in buildings is steadily growing. Implementing energy efficiency measures for reducing energy consumption in buildings can be an effective strategy for managing these impacts. Within commercial buildings in the United States, electricity use for lighting accounts for 26% (around 346 TWh in 2010) and represents a large potential energy savings source. Significant lighting energy savings have already been achieved through the widespread adoption of efficient fluorescent lamps and ballasts in the past several decades. Looking towards efficient lighting operations' innovations, wireless advanced lighting controls technology represents an increasingly viable option for capturing the next major level of lighting energy savings in new construction and building retrofits. Fundamentally, lighting is the most amenable building end use load for producing deep energy savings because of its dynamic controllability. Advanced lighting controls encompass control strategies from occupancy sensing to continuous dimming, institutional tuning and daylight harvesting. These strategies offer greater flexibility and higher granularity of control than traditional basic control methods. Historically, advanced control systems have required extensive control wiring, which has driven system costs. However, recently developed wireless lighting controls systems can be used to network lighting components, while potentially minimizing installation time and labor costs during retrofit in comparison to wired control systems.%8 04/2015 %2 LBNL-183791 %0 Journal Article %J Energy and Building %D 2014 %T Asset Rating with the Home Energy Scoring Tool %A Evan Mills %A Norman Bourassa %A Leo I. Rainer %A Gregory K. Homan %A Noel Market %A Danny S. Parker %A Glenn Dickey %A Joan Glickman %K Home rating %K residential %K validation %X
In 2010, as one of many energy initiatives within a broader economic stimulus program, the U.S. Department of Energy (DOE) and Lawrence Berkeley National Laboratory (LBNL) initiated development of a new web-based computer tool and method for providing an energy rating of existing single-family homes. The resulting Home Energy Scoring Tool is a key component of the DOE's Home Energy Score Program for residential building energy labeling, a voluntary national asset rating method that employs a simplified and standardized energy assessment process. The tool-development component of the program has been designed to support the energy audit marketplace by providing a substantially lower-cost, entry-level assessment method analogous to the fuel-economy ratings associated with vehicles. Averaged over a well-characterized sample of homes, the Home Energy Scoring tool is accurate to within 1% of mean weather-normalized energy bills (with 82% of homes having an absolute error of 25% or less), significantly better than two other popular methods known as SIMPLE and REM/Rate. This article presents technical details of the Home Energy Scoring Tool, and how it has evolved over time, including the calculation methodology, accuracy validation, and the web services feature that allows any qualified third-party software developer to integrate the methodology into their own web-based applications and market delivery strategy. As of April 2014, approximately 200 individuals had been qualified to deliver the assessments and had rated 10,600 homes in cooperation with 23 partner organizations across the United States.%B Energy and Building %V 80 %P 441-450 %8 09/2014 %G eng %R 10.1016/j.enbuild.2014.05.044 %0 Report %D 2014 %T Collaborative research to promote energy efficiency innovation towards significant reduction in buildings energy use in the United States and India %A Rajan Rawal %A Keyur Vadodaria %A Mona Galsar %A Girish Ghatikar %A Reshma Singh %A Diane Douglas %I Lawrence Berkeley National Laboratory %C Berkeley %8 03/2014 %2 LBNL-6862E %0 Journal Article %J Energy and Buildings %D 2014 %T Economic Comparison of White, Green, and Black Flat Roofs in the United States %A Julian Sproul %A Man-Pun Wan %A Benjamin H. Mandel %A Arthur H. Rosenfeld %K Building codes %K energy efficiency %K Green roofs %K Life-cycle cost analysis (LCCA) %K Stormwater management %K urban heat island %K White roofs %X
White and "green" (vegetated) roofs have begun replacing conventional black (dark-colored) roofs to mitigate the adverse effects of dark impervious urban surfaces. This paper presents an economic perspective on roof color choice using a 50-year life-cycle cost analysis (LCCA). We find that relative to black roofs, white roofs provide a 50-year net savings (NS) of $25/m2 ($2.40/ft2) and green roofs have a negative NS of $71/m2 ($6.60/ft2). Despite lasting at least twice as long as white or black roofs, green roofs cannot compensate for their installation cost premium. However, while the 50-year NS of white roofs compared to green roofs is $96/m2 ($8.90/ft2), the annualized cost premium is just $3.20/m2 -year ($0.30/ft2 -year). This annual difference is sufficiently small that the choice between a white and green roof should be based on preferences of the building owner. Owners concerned with global warming should choose white roofs, which are three times more effective than green roofs at cooling the globe. Owners concerned with local environmental benefits should choose green roofs, which offer built-in stormwater management and a "natural" urban landscape esthetic. We strongly recommend building code policies that phase out dark-colored roofs in warm climates to protect against their adverse public health externalities.%B Energy and Buildings %V 71 %P 20-27 %8 3/2014 %R 10.1016/j.enbuild.2013.11.058 %0 Report %D 2014 %T Effect of Fuel Wobbe Number on Pollutant Emissions from Advanced Technology Residential Water Heaters: Results of Controlled Experiments %A Vi H. Rapp %A Brett C. Singer %X
The research summarized in this report is part of a larger effort to evaluate the potential air quality impacts of using liquefied natural gas in California. A difference of potential importance between many imported liquefied natural gas blends and the natural gas blends that have been distributed in California in recent years is the higher Wobbe number of liquefied natural gas. Wobbe number is a measure of the energy delivery rate for appliances that use orifice- or pressure-based fuel metering. The effect of varying natural gas blends and associated Wobbe number on pollutant emissions from residential water heaters was evaluated in controlled experiments. Experiments were conducted on eight storage water heaters, including five with "ultra low-NOX" burners, and four on-demand (tankless) water heaters, all of which featured ultra low-NOX burners. Pollutant emissions were quantified as air-free concentrations in the appliance flue and fuel-based emission factors in units of nanogram of pollutant emitter per joule of fuel energy consumed. Emissions were measured for carbon monoxide (CO), nitrogen oxides (NOX), nitrogen oxide (NO), formaldehyde and acetaldehyde as the water heaters were operated through defined operating cycles using fuels with varying Wobbe number. The reference fuel was Northern California line gas with Wobbe number ranging from 1344 to 1365. Test fuels had Wobbe numbers of 1360, 1390 and 1420. The most prominent finding was an increase in NOX emissions with increasing Wobbe number: all five of the ultra low-NOX storage water heaters and two of the four ultra low-NOX on-demand water heaters had statistically discernible (p<0.10) increases in NOX with increasing fuel Wobbe number. The largest percentage increases occurred for the ultra low-NOX water heaters. There was a discernible change in CO emissions with changes in Wobbe number for all four of the on-demand devices tested. The on-demand water heater with the highest CO emissions also had the largest CO increase with increasing fuel Wobbe number.%2 LBNL-6626E %0 Journal Article %J Light & Engineering %D 2014 %T Field Study Methods and Results from a Market Trial of Night Market Vendors in Rural Kenya %A Alstone, P %A Radecsky, K %A Arne Jacobson %A Evan Mills %X
We evaluated the uptake of grid-independent LED lighting among night vendors in two small Kenyan towns during the "early days" of the solar- LED market. The methods we used combine social geography with energy and technology analysis to understand LED lighting adoption patterns in the context of a market that is getting its first exposure to LED technology, a situation that is repeating itself in villages and towns across the developing world. Of 23 night vendors to whom we offered LED lanterns at realistic market prices, 14 (61%) opted to purchase. We identified wide variations in baseline kerosene fuel use, significant fluctuations in the pricing of kerosene, an only partial degree to which kerosene was displaced, the value of highfrequency utilization information derived from embedded data loggers, consumer willingness to pay for improved lights, and significantly confounding effects of market spoiling due to prior experience with low-quality LED products. In a likely response to significant reductions in kerosene prices during the trial period, a non-adopter control group increased kerosene use by 70%.%B Light & Engineering %V 22 %G eng %U http://eds.b.ebscohost.com/abstract?site=eds&scope=site&jrnl=02362945&AN=96733129&h=qJCyBoRzBF%2b2zSEUC9HzfvkbOyJa7PqJkq6sR2%2bWEQ9tzkP9EoJQWxBG1%2fWbML%2b68y1JfLx7PUTpIxRWyobJhA%3d%3d&crl=f&resultLocal=ErrCrlNoResults&resultNs=Ehost&crlhashurl=login.aspx %N 2 %0 Report %D 2014 %T Formaldehyde and acetaldehyde exposure mitigation in US residences: In-home measurements of ventilation control and source control %A Erin L. Hult %A Henry Willem %A Phillip N. Price %A Toshifumi Hotchi %A Marion L. Russell %A Brett C. Singer %K acetaldehyde %K formaldehyde %K indoor air quality %K Indoor airPLUS %K LEED %K voc %X
Measurements were taken in new US residences to assess the extent to which ventilation and source control can mitigate formaldehyde exposure. Increasingventilation consistently lowered indoor formaldehyde concentrations. However, at a reference air exchange rate of 0.35 h-1, increasing ventilation was up to 60% less effective than would be predicted if the emission rate were constant. This is consistent with formaldehyde emission rates decreasing as air concentrations increase, as observed in chamber studies. In contrast, measurements suggest acetaldehyde emission was independent of ventilation rate. To evaluate the effectiveness of source control, formaldehyde concentrations were measured in Leadership in Energy and Environmental Design (LEED) certified/Indoor airPLUS homes constructed with materials certified to have low emission rates of volatile organic compounds (VOC). At a reference air exchange rate of 0.35 h-1, and adjusting for home age, temperature and relative humidity, formaldehyde concentrations in homes built with low-VOC materials were 42% lower on average than in reference new homes with conventional building materials. Without adjustment, concentrations were 27% lower in the low-VOC homes. The mean and standard deviation of formaldehyde concentration were 33 µg m-3 and 22 µg m-3 for low-VOC homes and 45 µg m-3 and 30 µ g m-3 for conventional.%2 LBNL-6886E %0 Journal Article %J Energy and Buildings %D 2014 %T Measured temperature reductions and energy savings from a cool tile roof on a central California home %A Pablo J. Rosado %A David Faulkner %A Douglas P. Sullivan %A Ronnen M. Levinson %K cool roof %B Energy and Buildings %V 80 %8 04/2014 %2 LBNL-1005104 %& 57 %R 10.1016/j.enbuild.1014.04.024 %0 Generic %D 2014 %T Reducing Residential Peak Electricity Demand with Mechanical Pre-Cooling of Building Thermal Mass %A William J. N. Turner %A Jordan Roux %A Iain S. Walker %K air conditioning %K Mechanical Cooling %K peak demand %K pre-cooling %K thermal mass %X
This study used an advanced airflow, energy and humidity modelling tool to evaluate the potential for residential mechanical pre-cooling strategies to reduce peak electricity demand. Simulations were performed for a typical new home in all US DOE Climate Zones. The results show that the effectiveness of pre-cooling is highly dependent on climate zone and the selected pre-cooling strategy. The expected energy trade-off between cooling peak energy savings and increased off-peak energy use is also shown. Best pre-cooling results for most climates were obtained using a short pre-cooling time window with a high pre-cooling set point temperature. All pre-cooling strategies caused the annual cooling energy demand of the simulated buildings to increase. However, pre-cooling for long time periods with a low temperature set point can eliminate up to 97% of the annual peak cooling load of the building%2 LBNL-180912 %0 Journal Article %J Solar Energy %D 2014 %T Reflectometer measurement of roofing aggregate albedo %A Ronnen M. Levinson %A Sharon S. Chen %A Paul H. Berdahl %A Pablo J. Rosado %A Medina, Louis A. %K albedo %K Pyranometer %K Roofing aggregate %K Solar reflectometer %X
A solar reflectometer is commonly used to determine the albedo of roofing products. This study validates against pyranometer measurements of albedo three new methods for solar reflectometer measurement of the albedo of the irregular surface presented by a bed of roofing aggregate. Method A determines the albedo of an aggregate bed by averaging many reflectometer readings of a small sample of aggregate. Method B relates the albedo of the aggregate bed to reflectometer measurements of the albedo of an opaquely thick pile of finely crushed aggregate. Method C relates the albedo of the aggregate bed to reflectometer measurements of the albedo of a faux roofing shingle surfaced with finely crushed aggregate. When applied to the 17 specimens tested in this study, Method A worked well for all but the largest aggregates; Methods B and C worked well for all aggregates. The absolute mean error of each method was less than 0.01, and the RMS error of each method did not exceed 0.021.
As an ancillary note, we find that beds of mineral particles have albedos that decrease with increasing particle size, up to sizes at which the particles become opaque to sunlight.%B Solar Energy %V 100 %P 159-171 %8 2/2014 %R 10.1016/j.solener.2013.11.006 %0 Journal Article %J Solar Energy Materials and Solar Cells %D 2014 %T Soiling of building envelope surfaces and its effect on solar reflectance – Part II: Development of an accelerated aging method for roofing materials %A Mohamad Sleiman %A Thomas W. Kirchstetter %A Paul H. Berdahl %A Haley E. Gilbert %A Quelen, Sarah %A Marlot, Lea %A Chelsea V. Preble %A Sharon S. Chen %A Amandine Montalbano %A Olivier Rosseler %A Hashem Akbari %A Ronnen M. Levinson %A Hugo Destaillats %K Accelerated aging %K cool roofs %K Natural exposure %K Soiling %K soot %K Weathering %X
Highly reflective roofs can decrease the energy required for building air conditioning, help mitigate the urban heat island effect, and slow global warming. However, these benefits are diminished by soiling and weathering processes that reduce the solar reflectance of most roofing materials. Soiling results from the deposition of atmospheric particulate matter and the growth of microorganisms, each of which absorb sunlight. Weathering of materials occurs with exposure to water, sunlight, and high temperatures. This study developed an accelerated aging method that incorporates features of soiling and weathering. The method sprays a calibrated aqueous soiling mixture of dust minerals, black carbon, humic acid, and salts onto preconditioned coupons of roofing materials, then subjects the soiled coupons to cycles of ultraviolet radiation, heat and water in a commercial weatherometer. Three soiling mixtures were optimized to reproduce the site-specific solar spectral reflectance features of roofing products exposed for 3 years in a hot and humid climate (Miami, Florida); a hot and dry climate (Phoenix, Arizona); and a polluted atmosphere in a temperate climate (Cleveland, Ohio). A fourth mixture was designed to reproduce the three-site average values of solar reflectance and thermal emittance attained after 3 years of natural exposure, which the Cool Roof Rating Council (CRRC) uses to rate roofing products sold in the US. This accelerated aging method was applied to 25 products–single ply membranes, factory and field applied coatings, tiles, modified bitumen cap sheets, and asphalt shingles–and reproduced in 3 days the CRRC's 3-year aged values of solar reflectance. This accelerated aging method can be used to speed the evaluation and rating of new cool roofing materials.%B Solar Energy Materials and Solar Cells %V 122 %P 271-281 %8 03/2014 %2 LBNL-6714E %& 271 %R 10.1016/j.solmat.2013.11.028 %0 Report %D 2013 %T Automated Measurement and Signaling Systems for the Transactional Network %A Mary Ann Piette %A Richard E. Brown %A Phillip N. Price %A Janie Page %A Jessica Granderson %A David Riess %A Stephen Czarnecki %A Girish Ghatikar %A Steven Lanzisera %X
The Transactional Network Project is a multi-lab activity funded by the US Department of Energy's Building Technologies Office. The project team included staff from Lawrence Berkeley National Laboratory, Pacific Northwest National Laboratory and Oak Ridge National Laboratory. The team designed, prototyped and tested a transactional network (TN) platform to support energy, operational and financial transactions between any networked entities (equipment, organizations, buildings, grid, etc.). PNNL was responsible for the development of the TN platform, with agents for this platform developed by each of the three labs. LBNL contributed applications to measure the whole-building electric load response to various changes in building operations, particularly energy efficiency improvements and demand response events. We also provide a demand response signaling agent and an agent for cost savings analysis. LBNL and PNNL demonstrated actual transactions between packaged rooftop units and the electric grid using the platform and selected agents. This document describes the agents and applications developed by the LBNL team, and associated tests of the applications.%I Lawrence Berkeley National Laboratory %C Berkeley %8 12/2013 %2 LBNL-6611E %0 Report %D 2013 %T Building Performance Simulation %A Tianzhen Hong %A Hung-Wen Lin %A Wen-Kuei Chang %A Liping Wang %A William J. N. Turner %A Da Yan %A Dandan Zhu %A Xin Zhou %A Chuang Wang %A Chen Peng %A Xiaoxin Ren %X
Buildings in the US and China consumed about 40% and 25% of the primary energy in both countries in 2010 respectively. Worldwide, the building sector is the largest contributor to the greenhouse gas emission. Better understanding and improving the energy performance of buildings is a critical step towards sustainable development and mitigation of global climate change.%8 06/2013 %2 LBNL-6418E %0 Generic %D 2013 %T The Business of High Performance: The USC Darla Moore School of Business %A Cynthia Regnier %A Kevin Settlemyre %2 LBNL-6904E %0 Generic %D 2013 %T Commercial Buildings Partnerships – Overview of Higher Education Projects %A Kristen Parrish %A Alastair Robinson %A Cynthia Regnier %8 02/2013 %2 LBNL-6903E %0 Journal Article %J Advances in Building Energy Research %D 2013 %T Cool roofs as a strategy to tackle global warming: economical and technical opportunities %A Federico Rossi %A Franco Cotana %A Mirko Filipponi %A Andrea Nicolini %A Surabi Menon %A Arthur H. Rosenfeld %K albedo %K CO2 offset %K cool roofs %K global warming %K high albedo surface %X
There is a growing consensus within the scientific community that the Earth's climate system is unequivocally warming and it is very likely (according to the formal uncertainty language used in the AR4, the term "very likely" refers to >90% assessed probability of occurrence) due to the increase in anthropogenic greenhouse gas concentrations. Urgent solutions need to be adopted, which are environmentally sustainable, in order to tackle global warming in the short term. At present, the most accredited global warming mitigation methods are represented by the emissions reduction technologies. Such technologies include energy from renewable sources such as solar and wind. A potential alternative is to modify the Earth's albedo by reflective surfaces (pavements and roofs), which are already employed to reduce building energy consumption and to mitigate heat island effects.
In this paper a procedure is proposed which evaluates the influence of changes in the Earth's albedo on the Earth's temperature and, as a consequence, quantifies the high albedo surface size required to compensate or offset global warming from changes in CO2. Additionally, a technical-economical comparison is carried out here between the proposed albedo system and the main technologies for the production of electric and thermal energy from renewable sources in order to evaluate its effectiveness in terms of cost of carbon dioxide equivalent (CO2eq) emission reduction.%B Advances in Building Energy Research %V 7 %P 254 - 268 %8 10/2013 %N 2 %& 254 %R 10.1080/17512549.2013.865555 %0 Report %D 2013 %T Data Analysis and Modeling of Lighting Energy Use in Large Office Buildings %A Xin Zhou %A Da Yan %A Xiaoxin Ren %A Tianzhen Hong %K building simulation %K energy use %K lighting %K modeling %K occupant behavior %K office buildings %K Poisson distribution %X
Lighting consumes about 20 to 40% of total electricity use in large office buildings in the U.S. and China. In order to develop better lighting simulation models it is crucial to understand the characteristics of lighting energy use. This paper analyzes the main characteristics of lighting energy use over various time scales, based on the statistical analysis of measured lighting energy use of 17 large office buildings in Beijing and Hong Kong. It was found that the daily 24-hour variations of lighting energy use were mainly driven by the schedule of the building occupants. Outdoor illumination levels have little impact on lighting energy use in large office buildings due to the lack of automatic daylighting controls and relatively small perimeter areas. A stochastic lighting energy use model was developed based on different occupant activities during six time periods throughout a day, and the annual distribution of lighting power across those periods. The model was verified using measured lighting energy use of one selected building. This study demonstrates how statistical analysis and stochastic modeling can be applied to lighting energy use. The developed lighting model can be adopted by building energy modeling programs to improve the simulation accuracy of lighting energy use.%0 Report %D 2013 %T Data Analysis and Modeling of Lighting Energy Use in Large Office Buildings %A Xin Zhou %A Da Yan %A Xiaoxin Ren %A Tianzhen Hong %K building simulation %K energy use %K lighting %K modeling %K occupant behavior %K office buildings %K Poisson distribution %X
Lighting consumes about 20 to 40% of total electricity use in large office buildings in the U.S. and China. In order to develop better lighting simulation models it is crucial to understand the characteristics of lighting energy use. This paper analyzes the main characteristics of lighting energy use over various time scales, based on the statistical analysis of measured lighting energy use of 17 large office buildings in Beijing and Hong Kong. It was found that the daily 24-hour variations of lighting energy use were mainly driven by the schedule of the building occupants. Outdoor illumination levels have little impact on lighting energy use in large office buildings due to the lack of automatic daylighting controls and relatively small perimeter areas. A stochastic lighting energy use model was developed based on different occupant activities during six time periods throughout a day, and the annual distribution of lighting power across those periods. The model was verified using measured lighting energy use of one selected building. This study demonstrates how statistical analysis and stochastic modeling can be applied to lighting energy use. The developed lighting model can be adopted by building energy modeling programs to improve the simulation accuracy of lighting energy use.%0 Conference Paper %B 2013 Energy Efficiency in Motor Driven Systems %D 2013 %T A Framework to Survey the Energy Efficiency of Installed Motor Systems %A Prakash Rao %A Ali Hasanbeigi %A Aimee T. McKane %K energy efficiency of motor systems %K motor systems %X
While motors are ubiquitous throughout the globe, there is insufficient data to properly assess their level of energy efficiency across regional boundaries. Furthermore, many of the existing data sets focus on motor efficiency and neglect the connected drive and system. Without a comprehensive survey of the installed motor system base, a baseline energy efficiency of a country or region's motor systems cannot be developed. The lack of data impedes government agencies, utilities, manufacturers, distributers, and energy managers when identifying where to invest resources to capture potential energy savings, creating programs aimed at reducing electrical energy consumption, or quantifying the impacts of such programs. This paper will outline a data collection framework for use when conducting a survey under a variety of execution models to characterize motor system energy efficiency within a country or region. The framework is intended to standardize the data collected ensuring consistency across independently conducted surveys. Consistency allows for the surveys to be leveraged against each other enabling comparisons to motor system energy efficiencies from other regions. In creating the framework, an analysis of various motor driven systems, including compressed air, pumping, and fan systems, was conducted and relevant parameters characterizing the efficiency of these systems were identified. A database using the framework will enable policymakers and industry to better assess the improvement potential of their installed motor system base particularly with respect to other regions, assisting in efforts to promote improvements to the energy efficiency of motor driven systems.%B 2013 Energy Efficiency in Motor Driven Systems %C Rio de Janeiro, Brazil %8 08/2013 %2 LBNL-1003886 %0 Journal Article %J Building Environment %D 2013 %T Indoor environmental quality benefits of apartment energy retrofits %A Federico Noris %A Gary Adamkiewicz %A William W. Delp %A Toshifumi Hotchi %A Marion L. Russell %A Brett C. Singer %A Michael Spears %A Kimberly Vermeer %A William J. Fisk %K apartments %K energy %K indoor environmental quality %K retrofit %K Selection %X
Sixteen apartments serving low-income populations in three buildings were retrofit with the goal of simultaneously reducing energy consumption and improving indoor environmental quality (IEQ). Retrofit measures varied among apartments and included, among others, envelope sealing, installation of continuous mechanical ventilation systems, upgrading bathroom fans and range hoods, attic insulation, replacement of heating and cooling systems, and adding wall-mounted particle air cleaners. IEQ parameters were measured, generally for two one-week periods before and after the retrofits. The measurements indicate an overall improvement in IEQ conditions after the retrofits. Comfort conditions, bathroom humidity, and concentrations of carbon dioxide, acetaldehyde, volatile organic compounds, and particles generally improved. Formaldehyde and nitrogen dioxide levels decreased in the building with the highest concentrations, were unchanged in a second building, and increased in a third building. IEQ parameters other than particles improved more in apartments with continuous mechanical ventilation systems installed. In general, but not consistently, larger percent increases in air exchange rates were associated with larger percent decreases in indoor levels of the pollutants that primarily come from indoor sources.%B Building Environment %V 68 %P 170–178 %8 10/2013 %2 LBNL-6373E %R 10.1016/j.buildenv.2013.07.003 %0 Journal Article %J Atmospheric Environment %D 2013 %T Investigation of formaldehyde and acetaldehyde sampling rate and ozone interference for passive deployment of Waters Sep-Pak XPoSure samplers %A Nasim A. Mullen %A Marion L. Russell %A Melissa M. Lunden %A Brett C. Singer %K Aldehyde %K exposure %K indoor air quality %K Passive sampler %K residential %X
This study investigated formaldehyde and acetaldehyde passive sampling rates and ozone interference for the DNPH-based Waters Sep-Pak XPoSure sampler. Previous studies have shown that ozone interferes with active sampling by this cartridge. Our study included one laboratory and six field experiments conducted in Northern California homes. Passive sampling rates of 1.10 ± 0.09 and 0.86 ± 0.10 mL/min determined for formaldehyde and acetaldehyde are lower than previously reported. In a controlled laboratory experiment there were small, statistically insignificant impacts of subsequent ozone exposure on formaldehyde and acetaldehyde mass passively collected on the samplers. This sampler is inexpensive, easy to deploy and to transport by mail, and has a high sampling capacity when used passively; it is suitable for a wide-range of monitoring applications. However, the passive sampling rate remains in question given the internally consistent, but different results obtained in our study and the previous study.%B Atmospheric Environment %V 80 %P 184-189 %8 12/2013 %R 10.1016/j.atmosenv.2013.07.074 %0 Generic %D 2013 %T Lights, Camera, Action ... and Cooling - The case for centralized low carbon energy at Fox Studios %A Alastair Robinson %A Cynthia Regnier %K low carbon %8 10/2013 %2 LBNL-182539 %0 Journal Article %J Advanced Optical Materials %D 2013 %T Near-Infrared Spectrally Selective Plasmonic Electrochromic Thin Films %A Guillermo Garcia %A Raffaella Buonsanti %A Anna Llordes %A Evan L. Runnerstrom %A Amy Bergerud %A Delia J. Milliron %K aluminum zinc oxide %K indium tin oxide %K nanocrystal %K spectroelectrochemistry %K surface plasmon %X
A plasmonic electrochromic effect in which electrochemical doping reversibly modulates near-infrared surface plasmon absorption of aluminium-doped zinc oxide and tin-doped indium oxide nanocrystals is reported. Optical performance, switching kinetics, and cycling durability point to high-performance NIR selective plasmonic electrochromic coatings based on earth-abundant materials.%B Advanced Optical Materials %V 1 %P 215 - 220 %8 03/2013 %N 3 %R 10.1002/adom.201200051 %0 Generic %D 2013 %T Oregon Sustainability Center: Weighing Approaches to Net Zero %A Cynthia Regnier %A Alastair Robinson %A Kevin Settlemyre %A Zorana Bosnic %K sustainabililty %8 10/2013 %2 LBNL-6916E %0 Report %D 2013 %T Predicting Backdrafting and Spillage for Natural-Draft Gas Combustion Appliances: Validating VENT-II %A Vi H. Rapp %A Albert Pastor-Perez %A Brett C. Singer %A Craig P. Wray %X
VENT-II is a computer program designed to provide detailed analysis of natural draft and induced draft combustion appliance vent-systems (i.e., furnace or water heater). This program is capable of predicting house depressurization thresholds that lead to backdrafting and spillage of combustion appliances; however, validation reports of the program being applied for this purpose are not readily available. The purpose of this report is to assess VENT-II's ability to predict combustion gas spillage events due to house depressurization by comparing VENT-II simulated results with experimental data for four appliance configurations.
The results show that VENT-II correctly predicts depressurizations resulting in spillage for natural draft appliances operating in cold and mild outdoor conditions, but not for hot conditions. In the latter case, the predicted depressurizations depend on whether the vent section is defined as part of the vent connector or the common vent when setting up the model. Overall, the VENTII solver requires further investigation before it can be used reliably to predict spillage caused by depressurization over a full year of weather conditions, especially where hot conditions occur.%8 04/2013 %2 LBNL-6193E %R 10.1080/10789669.2013.771948 %0 Generic %D 2013 %T Tips for Daylighting with Windows %A Alastair Robinson %A Stephen E. Selkowitz %2 LBNL-6902E %0 Report %D 2013 %T Tips for Daylighting with Windows: The Integrated Approach, 2nd Edition %A Jennifer Schumann %A Eleanor S. Lee %A Francis M. Rubinstein %A Stephen E. Selkowitz %A Alastair Robinson %X
These guidelines provide an integrated approach to the cost-effective design of perimeter zones in new commercial buildings and existing building retrofits. They function as a quick reference for building designers, through a set of easy steps and rules-of-thumb, emphasizing "how-to" practical details. References are given to more detailed sources of information, should the reader wish to go further.
The design method used in this document emphasizes that building decisions should be made within the context of the whole building as a single functioning system rather than as an assembly of distinct parts. This integrated design approach looks at the ramifications of each individual system decision on the whole building. For example, the decision on glazing selection will have an effect on lighting, mechanical systems, and interior design. Therefore, the entire design team should participate and influence this glazing decision—which typically rests with the architect alone. The benefit of an integrated design approach is a greater chance of success towards long-term comfort and sustained energy savings in the building.%0 Report %D 2013 %T Transforming BIM to BEM: Generation of Building Geometry for the NASA Ames Sustainability Base BIM %A James O'Donnell %A Tobias Maile %A Cody Rose %A Natasa Mrazovic %A Elmer Morrissey %A Cynthia Regnier %A Kristen Parrish %A Vladimir Bazjanac %8 01/2013 %2 LBNL-6033E %0 Report %D 2013 %T Ventilation Control of Volatile Organic Compounds in New U.S. Homes: Results of a Controlled Field Study in Nine Residential Units %A Henry Willem %A Erin L. Hult %A Toshifumi Hotchi %A Marion L. Russell %A Randy L. Maddalena %A Brett C. Singer %K formaldehyde %K residential %K ventilation %K vocs %X
In order to optimize strategies to remove airborne contaminants in residences, it is necessary to determine how contaminant concentrations respond to changes in the air exchange rate. The impact of air exchange rate on the indoor concentrations of 39 target volatile organic compounds (VOCs) was assessed by measuring air exchange rates and VOC concentrations at three ventilation settings in nine residences. Active sampling methods were used for VOC concentration measurements, and passive perfluorocarbon tracer gas emitters with active sampling were used to determine the overall air exchange rate corresponding to the VOC measurements at each ventilation setting. The concentration levels and emission rates of the target VOCs varied by as much as two orders of magnitude across sites. Aldehyde and terpene compounds were typically the chemical classes with highest concentrations, followed by alkanes, aromatics, and siloxanes. For each home, VOC concentrations tended to decrease as the air exchange rate was increased, however, measurement uncertainty was significant. The indoor concentration was inversely proportional to air exchange rate for most compounds. For a subset of compounds including formaldehyde, however, the indoor concentration exhibited a non-linear dependence on the timescale for air exchange.%2 LBNL-6022E %0 Report %D 2013 %T Zone Level Occupant-‐Responsive Building Energy Systems at the GSA %A Alastair Robinson %I Lawrence Berkeley National Laboratory %C Berkeley %8 03/2013 %2 LBNL-6887E %0 Conference Paper %B 2012 ACEEE Summer Study on Energy Efficiency in Buildings %D 2012 %T Accuracy of the Home Energy Saver Energy Calculation Methodology %A Danny S. Parker %A Evan Mills %A Leo I. Rainer %A Norman Bourassa %A Gregory K. Homan %X
The Home Energy Saver (HES) suite offers popular online simulation tools that enable U.S. homeowners and energy professionals to rigorously evaluate home energy use and develop recommendations on how energy can be saved across all end uses. The underlying analytical system is also available as a web service to power third-party energy analysis tools. Given the system's diverse uses, it is important that the simulation is robust and intrinsically accurate. While the engineering methods and assumptions are extensively documented and subjected to peer review, it is useful to evaluate how well HES predicts energy use in occupied homes. In this paper we compare measured to predicted energy use for 428 occupied homes in Oregon, Florida, and Wisconsin, representing a diversity building types, energy intensities, and occupant behaviors. We show how audit depth, knowledge of operational details, and submetered energy data can be valuable to the process of improving model accuracy—particularly for individual households, where energy use can vary three-fold for homes with virtually identical physical characteristics. Accuracy is strongly proportional to the quality and completeness of inputs, yet audit data are often deficient. Predictions are best—and the tendency of models to over-predict actual consumption is mitigated—when behavioral inputs match actual conditions. We find that Averaged across groups of homes, HES predicts energy use within 1% of actual consumption when physical characteristics and occupant behavior are well accounted for. New research findings are conferring even greater accuracy as they are incorporated into simulation tools.%B 2012 ACEEE Summer Study on Energy Efficiency in Buildings %I American Council for an Energy-Efficient Economy %C Washington, D.C. %G eng %0 Generic %D 2012 %T Achieving Energy Savings in Municipal Construction in Long Beach, CA %A Kristen Parrish %A Cynthia Regnier %K energy savings %8 11/2012 %2 LBNL-6921E %0 Journal Article %J Journal of Applied Physics %D 2012 %T Drifting localization of ionization runaway: Unraveling the nature of anomalous transport in high power impulse magnetron sputtering %A André Anders %A Pavel A Ni %A Albert Rauch %K Cameras %K ionization %K Magnetic fields %K Plasma density %K plasma ionization %X
The plasma over a magnetron's erosion "racetrack" is not azimuthally uniform but concentrated in distinct dense ionization zones which move in the E x B direction with about 10% of the electron E x B/B2 drift velocity. The ionization zones are investigated with a gated camera working in concert with a streak camera for Al, Nb, Cu, and W targets in Ar or Kr background gas. It is found that each ionization zone has a high plasma density edge, which is the origin of a plasma-generating electron jet leaving the target zone. Each region of strong azimuthal plasma density gradient generates an azimuthal electric field, which promotes the escape of magnetized electrons and the formation of electron jets and plasma flares. The phenomena are proposed to be caused by an ionization instability where each dense plasma zone exhibits a high stopping power for drifting high energy electrons, thereby enhancing itself.%B Journal of Applied Physics %V 111 %P 053304 %8 03/2012 %N 5 %! J. Appl. Phys. %R 10.1063/1.3692978 %0 Journal Article %J Journal of Combustion %D 2012 %T Extending Lean Operating Limit and Reducing Emissions of Methane Spark-Ignited Engines Using a Microwave-Assisted Spark Plug %A Vi H. Rapp %A Anthony DeFilippo %A Samveg Saxena %A Jyh-Yuan Chen %A Robert W. Dibble %A Atsushi Nishiyama %A Ahsa Moon %A Yuji Ikeda %X
A microwave-assisted spark plug was used to extend the lean operating limit (lean limit) and reduce emissions of an engine burning methane-air. In-cylinder pressure data were collected at normalized air-fuel ratios of λ=1.46, λ=1.51, λ=1.57, λ=1.68, and λ=1.75. For each λ, microwave energy (power supplied to the magnetron per engine cycle) was varied from 0 mJ (spark discharge alone) to 1600 mJ. At lean conditions, the results showed adding microwave energy to a standard spark plug discharge increased the number of complete combustion cycles, improving engine stability as compared to spark-only operation. Addition of microwave energy also increased the indicated thermal efficiency by 4% at λ=1.68. At λ=1.75, the spark discharge alone was unable to consistently ignite the air-fuel mixture, resulting in frequent misfires. Although microwave energy produced more consistent ignition than spark discharge alone at λ=1.75, 59% of the cycles only partially burned. Overall, the microwave-assisted spark plug increased engine performance under lean operating conditions (λ=1.68) but did not affect operation at conditions closer to stoichiometric.%B Journal of Combustion %V 2012 %8 07/2012 %R 10.1155/2012/927081 %0 Report %D 2012 %T Guide to Setting Thermal Comfort Criteria and Minimizing Energy Use in Delivering Thermal Comfort %A Cynthia Regnier %8 08/2012 %2 LBNL-6131E %0 Conference Proceedings %B 2012 ACEEE Summer Study on Energy Efficiency in Buildings %D 2012 %T The Home Energy Scoring Tool: A Simplified Asset Rating for Single Family Homes %A Norman Bourassa %A Leo I. Rainer %A Evan Mills %A Joan Glickman %X
In 2010, the U.S. Department of Energy (DOE) and Lawrence Berkeley National Laboratory (LBNL) initiated development of a new web-based computer tool and method for providing an energy asset rating of single-family homes. The resulting Home Energy Scoring Tool (http://homeenergyscore.lbl.gov) is a key component of the DOE's Home Energy Score Program (http://www.homeenergyscore.gov) for residential building energy labeling, a voluntary national asset rating method that uses a simplified and standardized energy assessment process. The Scoring Tool component of the program has been designed to support the existing energy analysis marketplace by providing a substantially lower-cost entry-level assessment method. This paper presents technical details of the Home Energy Scoring Tool itself, including the Scoring Tool's relationship to the Home Energy Saver building simulation engine, the Home Energy Score calculation methodology, and the web services feature that allows any qualified third-party software developer to integrate the Home Energy Score method into their own web based applications and market delivery strategy.%B 2012 ACEEE Summer Study on Energy Efficiency in Buildings %C Pacific Grove, CA, USA %8 05/2012 %2 LBNL-5714E %0 Generic %D 2012 %T Keeping Energy Savings in the LOOP %A Kristen Parrish %A Andrea C. Mercado %A Cynthia Regnier %K energy savings %K low-energy %K mixed-use %8 11/2012 %2 LBNL-6919E %0 Generic %D 2012 %T MIT - Mighty Steps for Energy Sustainability %A Alastair Robinson %A Cynthia Regnier %A Kevin Settlemyre %8 07/2012 %2 LBNL-6918E %0 Report %D 2012 %T Monitoring-based HVAC Commissioning of an Existing Office Building for Energy Efficiency %A Shankar Earni %A Spencer Woodworth %A Xiufeng Pang %A Jorge Hernandez-Maldonado %A Rongxin Yin %A Liping Wang %A Steve E. Greenberg %A John Fiegel %A Alma Rubalcava %K benchmarking %K commissioning %K energyplus %K fault detection and diagnostics %K functional testing %K trend data %X
The performance of Heating, Ventilation and Air Conditioning (HVAC) systems may fail to satisfy design expectations due to improper equipment installation, equipment degradation, sensor failures, or incorrect control sequences. Commissioning identifies and implements cost-effective operational and maintenance measures in buildings to bring them up to the design intent or optimum operation. An existing office building is used as a case study to demonstrate the process of commissioning. Building energy benchmarking tools are applied to evaluate the energy performance for screening opportunities at the whole building level. A large natural gas saving potential was indicated by the building benchmarking results. Faulty operations in the HVAC systems, such as improper operations of air-side economizers, simultaneous heating and cooling, and ineffective optimal start, were identified through trend data analyses and functional testing. The energy saving potential for each commissioning measure is quantified with a calibrated building simulation model. An actual energy saving of 10% was realized after the implementations of cost-effective measures.%8 10/2012 %2 LBNL-5940E %0 Report %D 2012 %T A Path to Successful Energy Retrofits: Early Collaboration Through Integrated Project Delivery Teams %A Kristen Parrish %A Cynthia Regnier %X
This document guides you through a process for the early design phases of retrofit projects to help you mitigate frustrations commonly experienced by building owners and designers. It outlines the value of forming an integrated project delivery team and developing a communication and information-sharing infrastructure that fosters collaboration. This guide does not present a complete process for designing an energy retrofit for a building. Instead, it focuses on the early design phase tasks related to developing and selecting energy efficiency measures (EEMs) that benefit from collaboration, and highlights the resulting advantages.%I Lawrence Berkeley National Laboratory %8 10/2012 %2 LBNL-6130E %0 Conference Paper %B IBPSA Building Simulation 2011 %D 2011 %T An Assessment of the use of Building Energy Performance Simulation in Early Design %A Vladimir Bazjanac %A Tobias Maile %A Cody Rose %A James O'Donnell %A Natasa Mrazovic %A Elmer Morrissey %A Welle, Benjamin %B IBPSA Building Simulation 2011 %C Sydney, Australia %8 11/2011 %G eng %0 Journal Article %J Energy and Buildings %D 2011 %T Calibrating whole building energy models: An evidence-based methodology %A Paul Raferty %A Marcus Keane %A James O'Donnell %K calibration %K Methodology %K retrofit %K simulation %K Version control %K Whole building energy model %X
This paper reviews existing case studies and methods for calibrating whole building energy models to measured data. This research describes a systematic, evidence-based methodology for the calibration of these models. Under this methodology, parameter values in the final calibrated model reference the source of information used to make changes to the initial model. Thus, the final model is based solely on evidence. Version control software stores a complete record of the calibration process, and the evidence on which the final model is based. Future users can review the changes made throughout the calibration process along with the supporting evidence. In addition to the evidence-based methodology, this paper also describes a new zoning process that represents the real building more closely than the typical core and four perimeter zone approach. Though the methodology is intended to apply to detailed calibration studies with high resolution measured data, the primary aspects of the methodology (evidence-based approach, version control, and zone-typing) are independent of the available measured data.%B Energy and Buildings %V 43 %P 2356-2364 %8 09/2011 %G eng %N 9 %& 2356 %R 10.1016/j.enbuild.2011.05.020 %0 Conference Paper %B Third ACM Workshop on Embedded Sensing Systems for Energy-Efficiency in Buildings %D 2011 %T Co-simulation based building controls implementation with networked sensors and actuators %A Yao-Jung Wen %A Dennis L. DiBartolomeo %A Francis M. Rubinstein %Y Ruzzelli, Antonio %X
The commercial building sector is one of the largest energy consumers in the U.S., and lighting, heating, ventilating and air conditioning contribute to more than half of the energy consumption and carbon emissions in buildings. Controls are the most effective way of increasing energy efficiency in building systems; however, the interdependencies among building subsystems must be taken into account to achieve deep energy savings. A networked sensing and actuation infrastructure shared among building systems is the key to optimal integrated control of the interdependent building elements in low energy and zero net energy buildings.
This paper presents a rapid-prototyping controls implementation platform based on the Building Controls Virtual Test Bed (BCVTB) framework that is capable of linking to building sensor and actuator networks for efficient controller design and testing. The platform creates a separation between the controls and the physical systems so that the controller can easily be implemented, tested and tuned with real performance feedback from a physical implementation. We realized an integrated lighting control algorithm using such a rapid-prototyping platform in a testing facility with networked sensors and actuators. This implementation has demonstrated an up to 57% savings in lighting electricity and 28% reduction in cooling demand.%B Third ACM Workshop on Embedded Sensing Systems for Energy-Efficiency in Buildings %I ACM Press %C Seattle, Washington %V Proceedings of BuildSys 2011 %P 55 %8 11/2011 %@ 9781450307499 %! BuildSys '11 %R 10.1145/2434020.2434040 %0 Conference Paper %B CIB W078-W102 %D 2011 %T Data Enviroments and Processing in Sem-Automated Simulation with EnergyPlus %A Vladimir Bazjanac %A Tobias Maile %A James O'Donnell %A Cody Rose %A Natasa Mrazovic %B CIB W078-W102 %C Sophia Antipolis, France %G eng %0 Journal Article %J Nano Letters %D 2011 %T Dynamically Modulating the Surface Plasmon Resonance of Doped Semiconductor Nanocrystals %A Guillermo Garcia %A Raffaella Buonsanti %A Evan L. Runnerstrom %A Rueben J. Mendelsberg %A Anna Llordes %A André Anders %A Thomas J. Richardson %A Delia J. Milliron %K doping %K indium tin oxide %K nanocrystal %K spectroelectrochemistry %K surface plasmon %X
Localized surface plasmon absorption features arise at high doping levels in semiconductor nanocrystals, appearing in the near-infrared range. Here we show that the surface plasmons of tin-doped indium oxide nanocrystal films can be dynamically and reversibly tuned by postsynthetic electrochemical modulation of the electron concentration. Without ion intercalation and the associated material degradation, we induce a > 1200 nm shift in the plasmon wavelength and a factor of nearly three change in the carrier density.%B Nano Letters %V 11 %P 4415 - 4420 %8 10/2011 %N 10 %! Nano Lett. %R 10.1021/nl202597n %0 Report %D 2011 %T Energy Information Handbook: Applications for Energy-Efficient Building Operations %A Jessica Granderson %A Mary Ann Piette %A Ben Rosenblum %A R. Lily Hu %A Daniel Harris %A Paul A. Mathew %A Phillip N. Price %A Geoffrey C. Bell %A Srinivas Katipamula %A Michael Brambley %K Building Operations %K Energy Information Handbook %K energy management %K Energy-Efficient %K Performance Tracking %X
There is a wealth of methods and tools to monitor and measure building energy use (both over the long haul and in real time) and to identify where best to focus your energy-efficiency efforts. But with so many options, where do you start? This handbook will give you the information you need to plan an energy-management strategy that works for your building, making it more energy efficient.%I Lawrence Berkeley National Laboratory %C Berkeley %8 12/2011 %G eng %2 LBNL-5272E %0 Report %D 2011 %T Extending the lean flammability limit of gasoline using a microwave assisted sparkplug %A A. DeFilippo %A Samveg Saxena %A Vi H. Rapp %A Jyh-Yuan Chen %A Robert W. Dibble %0 Conference Paper %B SC11 %D 2011 %T "Hot" for Warm Water Cooling %A Henry C. Coles %A Michael Ellsworth %A David J. Martinez %A Anna-Marie Bailey %A Farhad Banisadr %A Natalie Bates %A Susan Coghlan %A David E. Cowley %A Nicolas Dube %A Parks Fields %A Steve E. Greenberg %A Madhusudan Iyengar %A Peter R. Kulesza %A Josip Loncaric %A Tim McCann %A Greg Pautsch %A Michael K. Patterson %A Richard G. Rivera %A Greg K. Rottman %A Dale A. Sartor %A William F. Tschudi %A Wade Vinson %X
Liquid cooling is key to reducing energy consumption for this generation of supercomputers and remains on the roadmap for the foreseeable future. This is because the heat capacity of liquids is orders of magnitude larger than that of air and once heat has been transferred to a liquid, it can be removed from the datacenter efficiently. The transition from air to liquid cooling is an inflection point providing an opportunity to work collectively to set guidelines for facilitating the energy efficiency of liquid-cooled High Performance Computing (HPC) facilities and systems. The vision is to use non-compressor-based cooling, to facilitate heat re-use, and thereby build solutions that are more energy-efficient, less carbon intensive and more cost effective than their air-cooled predecessors. The Energy Efficient HPC Working Group is developing guidelines for warmer liquid-cooling temperatures in order to standardize facility and HPC equipment, and provide more opportunity for reuse of waste heat. This report describes the development of those guidelines.%B SC11 %C Seattle, WA %8 11/2011 %G eng %L LBNL-5128E %1
Applications Team%2 LBNL-5128E %0 Journal Article %J Applied Energy %D 2011 %T Potential benefits of solar reflective car shells: Cooler cabins, fuel savings and emission reductions %A Ronnen M. Levinson %A Heng Pan %A George A. Ban-Weiss %A Pablo J. Rosado %A Riccardo Paolini %A Hashem Akbari %K ADVISOR %K Cool Cars %K Cool colored car %K Heat Island %K Solar reflective shell %K Vehicle air conditioning %K Vehicle emission reduction %K Vehicle fuel economy %K windows and envelope materials group %X
Vehicle thermal loads and air conditioning ancillary loads are strongly influenced by the absorption of solar energy. The adoption of solar reflective coatings for opaque surfaces of the vehicle shell can decrease the "soak" temperature of the air in the cabin of a vehicle parked in the sun, potentially reducing the vehicle's ancillary load and improving its fuel economy by permitting the use of a smaller air conditioner. An experimental comparison of otherwise identical black and silver compact sedans indicated that increasing the solar reflectance (ρ) of the car's shell by about 0.5 lowered the soak temperature of breath-level air by about 5–6 °C. Thermal analysis predicts that the air conditioning capacity required to cool the cabin air in the silver car to 25 °C within 30 min is 13% less than that required in the black car. Assuming that potential reductions in AC capacity and engine ancillary load scale linearly with increase in shell solar reflectance, ADVISOR simulations of the SC03 driving cycle indicate that substituting a typical cool-colored shell (ρ = 0.35) for a black shell (ρ = 0.05) would reduce fuel consumption by 0.12 L per 100 km (1.1%), increasing fuel economy by 0.10 km L−1 [0.24 mpg] (1.1%). It would also decrease carbon dioxide (CO2) emissions by 2.7 g km−1 (1.1%), nitrogen oxide (NOx) emissions by 5.4 mg km−1 (0.44%), carbon monoxide (CO) emissions by 17 mg km−1 (0.43%), and hydrocarbon (HC) emissions by 4.1 mg km−1 (0.37%). Selecting a typical white or silver shell (ρ = 0.60) instead of a black shell would lower fuel consumption by 0.21 L per 100 km (1.9%), raising fuel economy by 0.19 km L−1 [0.44 mpg] (2.0%). It would also decrease CO2 emissions by 4.9 g km−1 (1.9%), NOx emissions by 9.9 mg km−1 (0.80%), CO emissions by 31 mg km−1 (0.79%), and HC emissions by 7.4 mg km−1 (0.67%). Our simulations may underestimate emission reductions because emissions in standardized driving cycles are typically lower than those in real-world driving.%B Applied Energy %V 88 %P 4343-4357 %8 12/2011 %N 12 %& 4343 %R 10.1016/j.apenergy.2011.05.006 %0 Conference Paper %B IBPSA Building Simulation 2011 %D 2011 %T SimModel: A domain data model for whole building energy simulation %A James O'Donnell %A Richard See %A Cody Rose %A Tobias Maile %A Vladimir Bazjanac %A Philip Haves %X
Many inadequacies exist within industry-standard data models as used by present-day whole-building energy simulation software. Tools such as EnergyPlus and DOE-2 use custom schema definitions (IDD and BDL respectively) as opposed to standardized schema definitions (defined in XSD, EXPRESS, etc.). Non-standard data modes lead to a requirement for application developers to develop bespoke interfaces. Such tools have proven to be error prone in their implementation – typically resulting in information loss.
This paper presents a Simulation Domain Model (SimModel) - a new interoperable XML-based data model for the building simulation domain. SimModel provides a consistent data model across all aspects of the building simulation process, thus preventing information loss. The model accounts for new simulation tool architectures, existing and future systems, components and features. In addition, it is a multi-representation model that enables integrated geometric and MEP simulation configuration data. The SimModel objects ontology moves away from tool-specific, non-standard nomenclature by implementing an industry-validated terminology aligned with Industry Foundation Classes (IFC).
The first implementation of SimModel supports translations from IDD, Open Studio IDD, gbXML and IFC. In addition, the EnergyPlus Graphic User Interface (GUI) employs SimModel as its internal data model. Ultimately, SimModel will form the basis for a new IFC Model View Definition (MVD) that will enable data exchange from HVAC Design applications to Energy Analysis applications. Extensions to SimModel could easily support other data formats and simulations (e.g. Radiance, COMFEN, etc.).%B IBPSA Building Simulation 2011 %8 10/2011 %G eng %2 LBNL-5566E %0 Report %D 2010 %T Achieving Energy Savings with Highly-Controlled Lighting in an Open-Plan Office %A Francis M. Rubinstein %A Abby I. Enscoe %X
An installation in a Federal building tested the effectiveness of a highly-controlled, workstation-specific lighting retrofit. The study took place in an open-office area with 86 cubicles and low levels of daylight. Each cubicle was illuminated by a direct/indirect pendant luminaire with three 32 watt lamps, two DALI ballasts, and an occupancy sensor. A centralized control system programmed all three lamps to turn on and off according to occupancy on a workstation-by-workstation basis. Field measurements taken over the course of several months demonstrated 40% lighting energy savings compared to a baseline without advanced controls that conforms to GSA's current retrofit standard. A photometric analysis found that the installation provided higher desktop light levels than the baseline, while an occupant survey found that occupants in general preferred the lighting system to the baseline. Simple payback is fairly high; projects that can achieve lower installation costs and/or higher energy savings and those in which greenhouse gas reduction and occupant satisfaction are significant priorities provide the ideal setting for workstation-specific lighting retrofits.%8 04/2010 %G eng %1
Windows and Daylighting Group%2 LBNL-3831E %0 Journal Article %J Journal of Building Performance Simulation %D 2010 %T A comparison of global optimization algorithms with standard benchmark functions and real-world applications using EnergyPlus %A Jérôme Henri Kämpf %A Michael Wetter %A Darren Robinson %K algorithm %K application using energyplus %K building energy minimization %K covariance matrix adaptation evolution strategy algorithm and hybrid differential evolution %K optimization %K particle swarm optimization and hooke-jeeves %X
There is an increasing interest in the use of computer algorithms to identify combinations of parameters which optimize the energy performance of buildings. For such problems, the objective function can be multi-modal and needs to be approximated numerically using building energy simulation programs. As these programs contain iterative solution algorithms, they introduce discontinuities in the numerical approximation to the objective function. Metaheuristics often work well for such problems, but their convergence to a global optimum cannot be established formally. Moreover, different algorithms tend to be suited to particular classes of optimization problems. To shed light on this issue we compared the performance of two metaheuristics, the hybrid CMA-ES/HDE and the hybrid PSO/HJ, in minimizing standard benchmark functions and real-world building energy optimization problems of varying complexity. From this we find that the CMA-ES/HDE performs well on more complex objective functions, but that the PSO/HJ more consistently identifies the global minimum for simpler objective functions. Both identified similar values in the objective functions arising from energy simulations, but with different combinations of model parameters. This may suggest that the objective function is multi-modal. The algorithms also correctly identified some non-intuitive parameter combinations that were caused by a simplified controls sequence of the building energy system that does not represent actual practice, further reinforcing their utility.%B Journal of Building Performance Simulation %V 3 %P 103-120 %G eng %N 2 %R 10.1080/19401490903494597 %0 Journal Article %J Environmental Research Letters %D 2010 %T Defining a standard metric for electricity savings %A Jonathan G. Koomey %A Hashem Akbari %A Carl Blumstein %A Marilyn A. Brown %A Richard E. Brown %A Chris Calwell %A Sheryl Carter %A Ralph Cavanagh %A Audrey Chang %A David Claridge %A Paul P. Craig %A Richard C. Diamond %A Joseph H Eto %A William Fulkerson %A Ashok J. Gadgil %A Howard S. Geller %A José Goldemberg %A Charles A. Goldman %A David B Goldstein %A Steve E. Greenberg %A David Hafemeister %A Jeffrey P. Harris %A Hal Harvey %A Eric Heitz %A Eric Hirst %A Holmes Hummel %A Daniel M. Kammen %A Henry Kelly %A John A. Laitner %A Mark D. Levine %A Amory Lovins %A Gil Masters %A James E. McMahon %A Alan K. Meier %A Michael Messenger %A John Millhone %A Evan Mills %A Steven M. Nadel %A Bruce Nordman %A Lynn K. Price %A Joseph J. Romm %A Marc Ross %A Michael Rufo %A Jayant A. Sathaye %A Leon J. Schipper %A Stephen H. Schneider %A James L. Sweeney %A Malcolm Verdict %A Diana Vorsatz %A Devra Wang %A Carl Weinberg %A Richard Wilk %A John Wilson %A Ernst Worrell %K energy efficiency %K energy policy %X
The growing investment by governments and electric utilities in energy efficiency programs highlights the need for simple tools to help assess and explain the size of the potential resource. One technique that is commonly used in that effort is to characterize electricity savings in terms of avoided power plants, because it is easier for people to visualize a power plant than it is to understand an abstraction like billions of kilowatt hours. Unfortunately, there is no standardization around the characteristics of such power plants. In this article we define parameters for a standard avoided power plant that have physical meaning and intuitive plausibility, for use in back-of-the-envelope calculations. For the prototypical plant this article settles on a 500-megawatt existing coal plant operating at a 70% capacity factor with 7% T&D losses. Displacing such a plant for one year would save 3 billion kWh/year at the meter and reduce emissions by 3 million metric tons of CO2 per year.The proposed name for this metric is the Rosenfeld, in keeping with the tradition among scientists of naming units in honor of the person most responsible for the discovery and widespread adoption of the underlying scientific principle in question – Dr. Arthur H. Rosenfeld.%B Environmental Research Letters %V 5 %8 03/2010 %G eng %N 1 %1
1.1%2 LBNL-2213E %! Environ. Res. Lett. %& 014017 %R 10.1088/1748-9326/5/1/014017 %0 Conference Paper %B Clima 2010 conference %D 2010 %T Energy Monitoring Systems value, issues and recommendations based on five case studies %A Paul Raferty %A Marcus Keane %A James O'Donnell %A Andrea Costa %B Clima 2010 conference %C Antalya, Turkey %G eng %0 Report %D 2010 %T Zero Net Energy Myths and Modes of Thought %A Nicholas B. Rajkovich %A Richard C. Diamond %A Bill Burke %X
The U.S. Department of Energy (DOE), the California Public Utilities Commission (CPUC), and a number of professional organizations have established a target of zero net energy (ZNE) in buildings by 2030. One definition of ZNE is a building with greatly reduced needs for energy through efficiency gains with the balance of energy needs supplied by renewable technologies. The push to ZNE is a response to research indicating that atmospheric concentrations of greenhouse gases have increased sharply since the eighteenth century, resulting in a gradual warming of the Earth's climate.
A review of ZNE policies reveals that the organizations involved frame the ZNE issue in diverse ways, resulting in a wide variety of myths and a divergent set of epistemologies. With federal and state money poised to promote ZNE, it is timely to investigate how epistemologies, meaning a belief system by which we take facts and convert them into knowledge upon which to take action, and the propagation of myths might affect the outcome of a ZNE program.
This paper outlines myths commonly discussed in the energy efficiency and renewable energy communities related to ZNE and describes how each myth is a different way of expressing "the truth." The paper continues by reviewing a number of epistemologies common to energy planning, and concludes that the organizations involved in ZNE should work together to create a "collaborative rationality" for ZNE. Through this collaborative framework it is argued that we may be able to achieve the ZNE and greenhouse gas mitigation targets.%I Lawrence Berkeley National Laboratory %C Berkeley %G eng %2 LBNL-3974E %0 Report %D 2009 %T Barrier Immune Radio Communications for Demand Response %A Francis M. Rubinstein %A Girish Ghatikar %A Jessica Granderson %A David S. Watson %A Paul Haugen %A Carlos Romero %X
Various wireless technologies were field-tested in a six-story laboratory building to identify wireless technologies that can scale for future DR applications through very low node density power consumption, and unit cost. Data analysis included analysis of the signal-to-noise ratio (SNR), packet loss, and link quality at varying power levels and node densities. The narrowband technologies performed well, penetrating the floors of the building with little loss and exhibiting better range than the wideband technology. 900 MHz provided full coverage at 1 watt and substantially complete coverage at 500 mW at the test site. 900 MHz was able to provide full coverage at 100 mW with only one additional relay transmitter, and was the highest-performing technology in the study. 2.4 GHz could not provide full coverage with only a single transmitter at the highest power level tested (63 mW). However, substantially complete coverage was provided at 2.4 GHz at 63 mW with the addition of one repeater node.%I Lawrence Berkeley National Laboratory %C Berkeley %8 02/2009 %G eng %2 LBNL-2294E %#
demand response%$
Commercial Building Systems%]
y%0 Generic %D 2009 %T Cool roofs could save money, save planet %A Hashem Akbari %A Arthur H. Rosenfeld %K cool roof %K Heat Island %B KGO-TV (abc7news) %8 03/2009 %G eng %U http://abclocal.go.com/kgo/story?section=news/drive_to_discover&id=6689052 %0 Journal Article %J Climatic Change %D 2009 %T Global cooling: increasing world-wide urban albedos to offset CO2 %A Hashem Akbari %A Surabi Menon %A Arthur H. Rosenfeld %K Advanced Very High Resolution Radiometer %K Global Cooling %K Heat Island %K Pave Surface %K Radiative Force %K Urban Surface %X
Increasing urban albedo can reduce summertime temperatures, resulting in better air quality and savings from reduced air-conditioning costs. In addition, increasing urban albedo can result in less absorption of incoming solar radiation by the surface-troposphere system, countering to some extent the global scale effects of increasing greenhouse gas concentrations. Pavements and roofs typically constitute over 60% of urban surfaces (roof 20–25%, pavements about 40%). Using reflective materials, both roof and pavement albedos can be increased by about 0.25 and 0.15, respectively, resulting in a net albedo increase for urban areas of about 0.1. On a global basis, we estimate that increasing the world-wide albedos of urban roofs and paved surfaces will induce a negative radiative forcing on the earth equivalent to offsetting about 44 Gt of CO2 emissions. At ~$25/tonne of CO2, a 44 Gt CO2 emission offset from changing the albedo of roofs and paved surfaces is worth about $1,100 billion. Furthermore, many studies have demonstrated reductions of more than 20% in cooling costs for buildings whose rooftop albedo has been increased from 10–20% to about 60% (in the US, potential savings exceed $1 billion per year). Our estimated CO2 offsets from albedo modifications are dependent on assumptions used in this study, but nevertheless demonstrate remarkable global cooling potentials that may be obtained from cooler roofs and pavements.%B Climatic Change %I Springer Netherlands %V 94 %P 275-286 %8 06/2009 %N 3-4 %R 10.1007/s10584-008-9515-9 %0 Journal Article %J Thin Solid Films %D 2009 %T High quality ZnO:Al transparent conducting oxide films synthesized by pulsed filtered cathodic arc deposition %A André Anders %A Sunnie H.N. Lim %A Kin Man Yu %A Joakim Andersson %A Johanna Rosén %A Mike McFarland %A Jeff Brown %X
Aluminum-doped zinc oxide, ZnO:Al or AZO, is a well-known n-type transparent conducting oxide with great potential in a number of applications currently dominated by indium tin oxide (ITO). In this study, the optical and electrical properties of AZO thin films deposited on glass and silicon by pulsed filtered cathodic arc deposition are systematically studied. In contrast to magnetron sputtering, this technique does not produce energetic negative ions, and therefore ion damage can be minimized. The quality of the AZO films strongly depends on the growth temperature while only marginal improvements are obtained with post-deposition annealing. The best films, grown at a temperature of about 200°C, have resistivities in the low to mid 10-4Ω cm range with a transmittance better than 85% in the visible part of the spectrum. It is remarkable that relatively good films of small thickness (60 nm) can be fabricated using this method.%B Thin Solid Films %G eng %L LBNL-1881E %1
Windows and Daylighting Group%2 LBNL-1881E %0 Conference Paper %B Building Simulation 2009 %D 2009 %T Key Factors - Methodology for Enhancement and Support of Building Energy Performance %A Andrea Costa %A Marcus Keane %A Paul Raferty %A James O'Donnell %X
This paper presents the Key Factors methodology that supports energy managers in determining the optimal building operation strategy in relation to both energy consumption and thermal comfort. The methodology is supported by the utilisation of calibrated building energy simulation models that match measured data gathered by an extensive measurement framework. The paper outlines the proposed methodology defining the underpinning concepts and illustrating the performance metrics required to capture the effect of different building operation strategies. A brief case study is discussed to demonstrate the application of the methodology.%B Building Simulation 2009 %C Glasgow, Scotland %G eng %U http://zuse.ucc.ie/iruse/papersNew/AndreaGlasgow.pdf %0 Conference Proceedings %B Silicon Valley Leadership Group Data Center Energy Efficiency Summit %D 2009 %T "The Monitoring," Panel: Chill-Off %A Dean Nelson %A Brian Day %A Geoffrey C. Bell %A Prajesh Bhattacharya %A Mike Ryan %B Silicon Valley Leadership Group Data Center Energy Efficiency Summit %C Sunnyvale, CA %8 10/2009 %G eng %0 Journal Article %J Optical Materials %D 2009 %T Optical characterization of fritted glass for architectural applications %A Jacob C. Jonsson %A Michael D. Rubin %A Annica M. Nilsson %A Andreas Jonsson %A Arne Roos %K BRDF %K BTDF %K Fritted glass %K Integrating sphere %K light scattering %X
Fritted glass is commonly used as a light diffusing element in modern buildings. Traditionally it has been used for aesthetic purposes but it can also be used for energy savings by incorporating it in novel daylighting systems? To answer such questions the light scattering properties must be properly characterized.
This paper contains measurements of different varieties of fritted glass, ranging from the simplest direct-hemispherical measurements to angle-resolved goniometer measurements. Modeling the light scattering to obtain the full bidirectional scattering distribution function (BSDF) extends the measured data, making it useful in simulation programs such as Window 6 and Radiance. Surface profilometry results and SEM micrographs are included to demonstrate the surface properties of the samples studied.%B Optical Materials %V 31 %P 949 - 958 %8 4/2009 %N 6 %! Optical Materials %R 10.1016/j.optmat.2008.10.050 %0 Generic %D 2009 %T Painting the town white: California Energy Commissioner, Art Rosenfeld, explains the benefits of cool roofs %A Arthur H. Rosenfeld %K cool roof %K Heat Island %B National Public Radio %G eng %U http://www.loe.org/shows/segments.htm?programID=09-P13-00007&segmentID=7 %0 Conference Paper %B 2008 ACEEE Summer Study on Energy Efficiency in Buildings, August 17-22, 2008 %D 2008 %T The Advantage of Highly Controlled Lighting for Offices and Commercial Buildings %A Francis M. Rubinstein %A Dmitriy Bolotov %A Mark S. Levi %A Kevin Powell %A Peter Schwartz %K demand response and distributed energy resources center %K demand response research center %K lighting %X
The paper presents results from pilot studies of new "workstation-specific" luminaires that are designed to provide highly, efficient, customized lighting for open-office cubicles. Workstation specific luminaires have the following characteristics: 1) they provide separate, dimming control of the cubicle's "ambient" and "task" lighting components, 2) occupancy sensors and control photosensors are integrated into the fixture's design and operation, 3) luminaires can be networked using physical cabling, microcontrollers and a PC running control software. The energy savings, demand response capabilities and quality of light from the two WS luminaires were evaluated and compared to the performance of a static, low-ambient lighting system that is uncontrolled. Initial results from weeks of operation provide strong indication that WS luminaires can largely eliminate the unnecessary lighting of unoccupied cubicles while providing IESNA-required light levels when the cubicles are occupied. Because each cubicle's lighting is under occupant sensor control, the WS luminaires can capitalize on the fact cubicles are often unoccupied during normal working hours and reduce their energy use accordingly.%B 2008 ACEEE Summer Study on Energy Efficiency in Buildings, August 17-22, 2008 %C Pacific Grove, CA %P 063901(1-5) %8 08/2008 %G eng %1
Lighting Systems Group%2 LBNL-2514E %0 Journal Article %J Environmental Science and Technology %D 2008 %T Carbonyl Emissions from Gasoline and Diesel Motor Vehicles %A Chris A. Jakober %A Michael A. Robert %A Sarah G. Riddle %A Hugo Destaillats %A M. Judith Charles %A Peter G. Green %A Michael J. Kleeman %X
Carbonyls from gasoline-powered light-duty vehicles (LDVs) and heavy-duty diesel-powered vehicles (HDDVs) operated on chassis dynamometers were measured by use of an annular denuder−quartz filter−polyurethane foam sampler with O-(2,3,4,5,6-pentafluorobenzyl)hydroxylamine derivatization and chromatography−mass spectrometry analyses. Two internal standards were utilized based on carbonyl recovery: 4-fluorobenzaldehyde for <C8 carbonyls and 6-fluoro-4-chromanone for ≥C8 compounds. Gas- and particle-phase emissions for 39 aliphatic and 20 aromatic carbonyls ranged from 0.1 to 2000 µg/L of fuel for LDVs and from 1.8 to 27 000 µg/L of fuel for HDDVs. Gas-phase species accounted for 81−95% of the total carbonyls from LDVs and 86−88% from HDDVs. Particulate carbonyls emitted from a HDDV under realistic driving conditions were similar to concentrations measured in a diesel particulate matter (PM) standard reference material. Carbonyls accounted for 19% of particulate organic carbon (POC) emissions from low-emission LDVs and 37% of POC emissions from three-way catalyst-equipped LDVs. This identifies carbonyls as one of the largest classes of compounds in LDV PM emissions. The carbonyl fraction of HDDV POC was lower, 3.3−3.9% depending upon operational conditions. Partitioning analysis indicates the carbonyls had not achieved equilibrium between the gas and particle phases under the dilution factors of 126−584 used in the present study.%B Environmental Science and Technology %V 42 %P 4697-4703 %8 05/2008 %G eng %N 13 %1
7.1%! Environ. Sci. Technol. %& 4697 %R 10.1021/es7029174 %0 Journal Article %J Thin Solid Films %D 2008 %T Electrochromically switched, gas-reservoir metal hydride devices with application to energy-efficient windows %A André Anders %A Jonathan L. Slack %A Thomas J. Richardson %X
Proof-of-principle gas-reservoir MnNiMg electrochromic mirror devices have been investigated. In contrast to conventional electrochromic approaches, hydrogen is stored (at low concentration) in the gas volume between glass panes of the insulated glass units (IGUs). The elimination of a solid state ion storage layer simplifies the layer stack, enhances overall transmission, and reduces cost. The cyclic switching properties were demonstrated and system durability improved with the incorporation a thin Zr barrier layer between the MnNiMg layer and the Pd catalyst. Addition of 9% silver to the palladium catalyst further improved system durability. About 100 full cycles have been demonstrated before devices slow considerably. Degradation of device performance appears to be related to Pd catalyst mobility, rather than delamination or metal layer oxidation issues originally presumed likely to present significant challenges.%B Thin Solid Films %C Eindhoven, Netherlands %V 1 %8 08/2003 %G eng %L LBNL-1089E %1
Windows and Daylighting Group%2 LBNL-1089E %0 Report %D 2008 %T Equivalent CO2 avoided by reflective roofs and pavements in California %A Hashem Akbari %A Surabi Menon %A Arthur H. Rosenfeld %K Global Cooling %K Heat Island %B Memo to California Air Resources Board %8 10/2008 %G eng %0 Conference Paper %B SPIE Optics+Photonics %D 2008 %T Light-scattering properties of a woven shade-screen material used for daylighting and solar heat-gain control %A Jacob C. Jonsson %A Eleanor S. Lee %A Michael D. Rubin %X
Shade-screens are widely used in commercial buildings as a way to limit the amount of direct sunlight that can disturb people in the building. The shade screens also reduce the solar heat-gain through glazing the system. Modern energy and daylighting analysis software such as EnergyPlus and Radiance require complete scattering properties of the scattering materials in the system.
In this paper a shade screen used in the LBNL daylighting testbed is characterized using a photogoniometer and a normal angle of incidence integrating sphere. The data is used to create a complete bi-directional scattering distribution function (BDSF) that used in simulation programs.
The resulting BDSF is compared to a model's BDSF, both directly and by calculating the solar heat-gain coefficient for a dual-pane system using Window 6.%B SPIE Optics+Photonics %C San Diego, CA %8 08/2008 %G eng %L LBNL-828E %1
Windows and Daylighting Group%2 LBNL-828E %0 Journal Article %J ASHRAE Journal %D 2008 %T Metrics and Benchmarks for Energy Efficiency in Laboratories %A Paul A. Mathew %A Steve E. Greenberg %A Dale A. Sartor %A Peter Rumsey %X
A wide spectrum of laboratory owners, ranging from universities to federal agencies, have explicit goals for energy efficiency in their facilities. For example, the Energy Policy Act of 2005 (EPACT 2005) requires all new federal buildings to exceed ASHRAE 90.1-2004 by at least 30%. A new laboratory is much more likely to meet energy efficiency goals if quantitative metrics and targets are specified in programming documents and tracked during the course of the delivery process. If not, any additional capital costs or design time associated with attaining higher efficiencies can be difficult to justify.
This article describes key energy efficiency metrics and benchmarks for laboratories, which have been developed and applied to several laboratory buildings — both for design and operation. In addition to traditional whole building energy use metrics (e.g. BTU/ft2.yr, kWh/m2.yr), the article describes HVAC system metrics (e.g. ventilation W/cfm, W/L.s-1), which can be used to identify the presence or absence of energy features and opportunities during design and operation.%B ASHRAE Journal %P 40-47 %G eng %L LBNL-357E %1
Applications Team%2 LBNL-357E %0 Journal Article %J Phase Transitions %D 2008 %T Phase transitions in non-hydride switchable mirror thin films %A Thomas J. Richardson %K electrochromism %K optoelectronics %K Switchable mirrors %K thin films %X
Switchable mirrors modulate incident light by changes in the reflectivity of thin films that are converted by chemical reactions from a metallic reflective state to a semiconducting transparent state. The reactions may be effected by exposure to a gas, by treatment with a liquid reagent, or by electrochemical means. The changes in optical properties coincide with phase transformations. In the examples reviewed here, the reactions are accompanied by substantial volume changes and atomic rearrangement. Bismuth, antimony, and antimony alloy films are switched by electrochemical lithiation. Copper films are electrochemically oxidized to Cu(I) and Cu(II) oxides, which are transparent and opaque, respectively. Morphological changes in all films during cycling lead to degradation in performance without loss of active material. Strategies to improve the cycling stability of these systems are discussed.%B Phase Transitions %V 81 %P 807 - 813 %8 07/2008 %N 7-8 %! Phase Transitions %R 10.1080/01411590801911406 %0 Conference Paper %B 16th Symposium on Improving Building Systems in Hot and Humid Climates, December 15-17, 2008 %D 2008 %T Reducing Energy Use In Florida Buildings %A Richard Raustad %A Mangesh Basarkar %A Robin K. Vieira %X
The 2007 Florida Building Code (ICC, 2008) requires building designers and architects to achieve a minimum energy efficiency rating for commercial buildings located throughout Florida. Although the Florida Building Code is strict in the minimum requirements for new construction, several aspects of building construction can be further improved through careful thought and design. This report outlines several energy saving features that can be used to ensure that new buildings meet a new target goal of 85% energy use compared to the 2007 energy code in order to achieve Governor Crist's executive order to improve the energy code by 15%.
To determine if a target goal of 85% building energy use is attainable, a computer simulation study was performed to determine the energy saving features available which are, in most cases, stricter than the current Florida Building Code. The energy savings features include improvements to building envelop, fenestration, lighting and equipment, and HVAC efficiency. The imp acts of reducing outside air requirements and employing solar water heating were also investigated. Th e purpose of the energy saving features described in this document is intended to provide a simple, prescriptive method for reducing energy consumption using the methodology outlined in ASHRAE Standard 90.1 (ASHRAE, 2007).
There are two difficulties in trying to achieve savings in non-residential structures. First, there is significant energy use caused by internal loads for people and equipment and it is difficult to use the energy code to achieve savings in this area relative to a baseline. Secondly, the ASHRAE methodology uses some of the same features that are proposed for the new building, so it may be difficult to claim savings for some strategies that will produce savings such as improved ventilation controls, reduced window area, or reduced plug loads simply because the methodology applies those features to the comparison reference building.
Several measures to improve the building envelope characteristics were simulated. Simply using the selected envelope measures resulted in savings of less than 10% for all building types. However, if such measures are combined with aggressive lighting reductions and improved efficiency HVAC equipment and controls, a target savings of 15% is easily attainable.%B 16th Symposium on Improving Building Systems in Hot and Humid Climates, December 15-17, 2008 %C Dallas, TX %8 12/2008 %G eng %0 Journal Article %J Journal of the Human-Environmental System %D 2008 %T Urban Surfaces and Heat Island Mitigation Potentials %A Hashem Akbari %A Leanna S. Rose %K Cool Pavements %K cool roofs %K Heat Island %K heat island mitigation %K land use/land cover %K orthophotography %K urban fabric %X
Data on materials and surface types that comprise a city, i.e. urban fabric, are needed in order to estimate the effects of light-colored surfaces (roofs and pavements) and urban vegetation (trees, grass, shrubs) on the meteorology and air quality of a city. We discuss the results of a semi-automatic statistical approach used to develop data on surface-type distribution and urban-fabric makeup using aerial color orthophotography, for four metropolitan areas of Chicago, IL, Houston, TX, Sacramento, CA, and Salt Lake City, UT. The digital high resolution (0.3 to 0.5-m) aerial photographs for each of these metropolitan areas covers representative urban areas ranging from 30 km2 to 52 km2.
Major land-use types examined included: commercial, residential, industrial, educational, and transportation. On average, for the metropolitan areas studied, vegetation covers about 29-41% of the area, roofs 19-25%, and paved surfaces 29-39%. For the most part, trees shade streets, parking lots, grass, and sidewalks. At ground level, i.e., view from below the tree canopies, vegetation covers about 20-37% of the area, roofs 20-25%, and paved surfaces 29-36%.%B Journal of the Human-Environmental System %V 11 %P 85-101 %G eng %N 2 %& 85 %R 10.1618/jhes.11.85 %0 Report %D 2008 %T White roofs cool the world, directly offset CO2 and delay global warming %A Hashem Akbari %A Arthur H. Rosenfeld %K cool roof %K Heat Island %B Research Highlights %8 11/2008 %G eng %0 Report %D 2008 %T WINDOW 6.2/THERM 6.2 Research Version User Manual %A Robin Mitchell %A Christian Kohler %A Joseph H. Klems %A Michael D. Rubin %A Dariush K. Arasteh %A Charlie Huizenga %A Tiefeng Yu %A Dragan C. Curcija %X
WINDOW 6 and THERM 6 Research Versions are software programs developed at Lawrence Berkeley National Laboratory (LBNL) for use by manufacturers, engineers, educators, students, architects, and others to determine the thermal and solar optical properties of glazing and window systems.
WINDOW 6 and THERM 6 are significant updates to LBNL's WINDOW 5 and THERM 5 computer program because of the added capability to model complex glazing systems, such as windows with shading systems, in particular venetian blinds. Besides a specific model for venetian blinds and diffusing layers, WINDOW 6 also includes the generic ability to model any complex layer if the Transmittance and Reflectance are known as a function of incoming and outgoing angles.
The algorithms used in these versions of the programs to determine the properties of windows with shading layers are relatively new and should be considered as informative but not definitive.
As such, for windows with shading layers, the results are intended for research purposes only. Pending further validation efforts, results for windows with sh ading layers should not be used for NFRC certified calculations of design decisions in real buildings.
All calculations for products without shading layers are identical to those from WINDOW 5.2.
WINDOW 6 Research Version includes all of the WINDOW 5 capabilities with the addition of shading algorithms from ISO15099 which are incorporated into the program, as well as an extension of those algorithms with the matrix calculation method.
THERM 6 Research Version includes all of the THERM 5 capabilities with the addition of being able to import and model WINDOW 6 glazing systems with shading devices. Those THERM 6 files with shading devices can them be imported into the WINDOW 6 Frame Library and whole windows with shading devices can then be modeled in WINDOW 6.%I Lawrence Berkeley National Laboratory %C Berkeley %P 1-126 %8 01/2008 %G eng %1
Windows and Daylighting Group%2 LBNL-813E %0 Report %D 2007 %T Controls for Solid-State Lighting %A Francis M. Rubinstein %X
This study predicts new hybrid lighting applications for LEDs. In hybrid lighting, LEDs provide a low-energy "standby" light level while another, more powerful, efficient light source provides light for occupied periods. Lighting controls will allow the two light sources to work together through an appropriate control strategy, typically motion-sensing. There are no technical barriers preventing the use of low through high CRI LEDs for standby lighting in many interior and exterior applications today.
The total luminous efficacy of LED systems could be raised by increasing the electrical efficiency of LED drivers to the maximum practically achievable level (94%). This would increase system luminous efficacy by 20-25%. The expected market volumes for many types of LEDs should justify the evolution of new LED drivers that use highly efficient ICs and reduce parts count by means of ASICs. Reducing their electronics parts count by offloading discrete components onto integrated circuits (IC) will allow manufacturers to reduce the cost of LED driver electronics.
LED luminaire manufacturers will increasingly integrate the LED driver and thermal management directly in the LED fixture. LED luminaires of the future will likely have no need for separable lamp and ballast because the equipment life of all the LED luminaire components will all be about the same (50,000 hours).
The controls and communications techniques used for communicating with conventional light sources, such as dimmable fluorescent lighting, are appropriate for LED illumination for energy management purposes. DALI has been used to control LED systems in new applications and the emerging ZigBee protocol could be used for LEDs as well. Major lighting companies are already moving in this direction.
The most significant finding is that there is a significant opportunity to use LEDs today for standby lighting purposes. Conventional light ing systems can be made more efficient still by using LEDs to provide a low-energy standby state when lower light levels are acceptable.%G eng %L LBNL-63249 %1
Lighting Systems Group%2 LBNL-63249 %0 Journal Article %J Building and Environment %D 2007 %T Cooler tile-roofed buildings with near-infrared-reflective non-white coatings %A Ronnen M. Levinson %A Hashem Akbari %A Joseph C. Reilly %K building simulation %K california %K Cool coating %K cool roof %K cooling energy %K Cooling power %K Heat Island %K Near-infrared reflectance %K Solar reflectance %K Tile roof %X
Owners of homes with pitched roofs visible from ground level often prefer non-white roofing products for aesthetic considerations. Non-white, near-infrared-reflective architectural coatings can be applied in situ to pitched concrete or clay tile roofs to reduce tile temperature, building heat gain, and cooling power demand, while simultaneously improving the roof's appearance. Scale-model measurements of building temperature and heat-flux were combined with solar and cooling energy use data to estimate the effects of such cool-roof coatings in various California climates. Under typical conditions—e.g., 1 kWm-2 summer afternoon insolation, R-11 attic insulation, no radiant barrier, and a 0.3 reduction in solar absorptance—absolute reductions in roof surface temperature, attic air temperature, and ceiling heat-flux are about 12, 6.2 K, and 3.7 Wm-2, respectively. For a typical 1,500 ft2 (139m2)house with R-11 attic insulation and no radiant barrier, reducing roof absorptance by 0.3 yields whole-house peak power savings of 230 W in Fresno, 210 W in San Bernardino, and 210 W in San Diego. The corresponding absolute and fractional cooling energy savings are 92 kWhyr-1 (5%), 67kWhyr-1 (6%), and 8kWhyr-1 (1%), respectively. These savings are about half those previously reported for houses with non-tile roofs. With these assumptions, the statewide peak cooling power and annual cooling energy reductions would be 240 MW and 63 GWhyr-1, respectively. Statewide energy savings would reduce annual emissions from California power plants by 35 kton CO2, 1.1 ton NOx, and 0.86 ton SOx. The economic value of cooling energy savings is well below the cost of coating a tile roof, but the simple payback times for using cool pigments in a roof tile coating are modest (5-7 yr) in the warm climates of Fresno and San Bernardino.%B Building and Environment %V 42 %P 2591-2605 %8 07/2007 %G eng %N 7 %& 2591 %R 10.1016/j.buildenv.2006.06.005 %0 Report %D 2007 %T Daylighting the New York Times Headquarters Building: Final Report: Commissioning Daylighting Systems and Estimation of Demand Response %A Eleanor S. Lee %A Glenn D. Hughes %A Robert D. Clear %A Luis L. Fernandes %A Sila Kiliccote %A Mary Ann Piette %A Francis M. Rubinstein %A Stephen E. Selkowitz %K automated daylighting controls %K automated window shades %K daylighting %K demand response %K energy-efficiency %K visual comfort %X
The technical energy-savings potential for smart integrated window-daylighting systems is excellent and can yield significant reductions in US commercial building energy use if adopted by a significant percentage of the market. However, conventional automated shades and daylighting controls have been commercially available for over two decades with less than 1-2% market penetration in the US. As with many innovations, the problem with accelerating market adoption is one of demonstrating real performance and decreasing risk and cost. The New York Times considered use of such daylighting systems for their new 139,426 m2 (1.5 Mft2) headquarters building in downtown Manhattan.
In the initial phase of work, The New York Times employed a unique approach to create a competitive marketplace for daylighting systems and to address their concerns about risk by building a full-scale daylighting mockup and evaluating commercially-available products. This field test formed the strategic cornerstone for accelerating an industry response to the building owners' challenge to a sleepy market. A procurement specification was produced and bids were received that met The Times cost-effective criteria. The Times decided to proceed with using these innovative systems in their new building.
This next phase of work consisted of two distinct tasks: 1) to develop and use commissioning tools and procedures to insure that the automated shade and daylighting control systems operate as intended prior to occupancy; and 2) to estimate the peak demand savings resulting from different levels of demand response (DR) control strategies (from moderate to severe load curtailment) and then determine the financial implications given various DR programs offered by the local utility and New York Independent System Operator in the area.
Commissioning daylighting control systems is mandatory to insure that design intent is met, that the systems are tuned to optimal performance, and to eliminate problems and errors before occupants move in. Commissioning tools were developed and procedures were defined and then used to verify that the daylighting systems operated according to the technical specifications. For both lighting control and shading systems, the Times and the manufacturers were able to resolve most of the bugs and fine-tune the systems prior to occupancy.
The demand response (DR) strategies at the New York Times building involve unique state-of-the-art systems with dimmable ballasts, movable shades on the glass facade, and underfloor air HVAC. The process to develop the demand response strategies, the results of the EnergyPlus model, the activities to implement the DR strategies in the controls design at the New York Times Headquarters building and the evaluation of economics of participating in DR programs are presented and discussed. The DR simulation iv efforts for this building design are novel, with an innovative building owner evaluating DR and future DR program participation strategies during the design and construction phase using advanced simulation tools.%C Berkeley %8 08/2007 %0 Conference Paper %B 2nd PALENC and 28th AIVC Conference %D 2007 %T Global cooling: effect of urban albedo on global temperature %A Hashem Akbari %A Surabi Menon %A Arthur H. Rosenfeld %K Global Cooling %K Heat Island %X
In many urban areas, pavements and roofs constitute over 60% of urban surfaces (roof 20-25%, pavements about 40%). The roof and the pavement albedo can be increased by about 0.25 and 0.10, respectively, resulting in a net albedo increase for urban areas of about 0.1.
Many studies have demonstrated building cooling-energy savings in excess of 20% upon raising roof reflectivity from an existing 10-20% to about 60%. We estimate U.S. potential savings in excess of $1 billion (B) per year in net annual energy bills. Increasing albedo of urban surfaces can reduce the summertime urban temperature and improve the urban air quality.
Increasing the urban albedo has the added benefit of reflecting more of the incoming global solar radiation and countering the effect of global warming. We estimate that increasing albedo of urban areas by 0.1 results in an increase of 3x10-4 in Earth albedo. Using a simple global model, the change in air temperature in lowest 1.8 km of the atmosphere is estimated at 0.01K. Modelers predict a warming of about 3K in the next 60 years (0.05K/year). Change of 0.1 in urban albedo will result in 0.01K global cooling, a delay of ~0.2 years in global warming. This 0.2 years delay in global warming is equivalent to 10 Gt reduction in CO2 emissions.%B 2nd PALENC and 28th AIVC Conference %C Crete %P 1-5 %8 09/2007 %G eng %U http://www.escholarship.org/uc/item/0pz748p6 %0 Report %D 2007 %T Green the Capitol Initiative, Final Report %A Daniel P. Beard %A Grant Scherling %A Perry Plumart %A Barbara A. Atkinson %A Peter J. Biermayer %A Richard E. Brown %A Richard C. Diamond %A Camilla Dunham %A Ryan M. Firestone %A Steve E. Greenberg %A Don Medley %A Anthony Ma %A Alan K. Meier %A Evan Mills %A Bruce Nordman %A Christopher T. Payne %A Mary Ann Piette %A Francis M. Rubinstein %A Stephen E. Selkowitz %A Craig P. Wray %A Peng Xu %A Mike Azarcon %A Jim Calendar %A Tom Costello %A Eric Goodman %A Greg Green %A Charles Iliff %A Brian Klein %A Mike Laser %A William Miller %A Dan Murphy %A Theon Parker %A Dave Pilkins %A Chris Potter %A Louis Scalfari %A Toby Virts %A John Williams %A Rick Wilmoth %A Beverly Wood %I Chief Administrative Officer of the U.S. House of Representatives %C Washington DC %8 06/2007 %G eng %2 LBNL-2605 %0 Journal Article %J Solar Energy Materials and Solar Cells %D 2007 %T Methods of creating solar-reflective nonwhite surfaces and their application to residential roofing materials %A Ronnen M. Levinson %A Paul H. Berdahl %A Hashem Akbari %A William A. Miller %A Ingo Joedicke %A Joseph C. Reilly %A Yoshi Suzuki %A Michelle Vondran %K absorption %K asphalt shingle %K clay tile %K coating %K concrete tile %K conversion coating %K Heat Island %K metal %K Methods & Protocols %K near infrared %K pigment %K reflective %K residential %K roofing %K scattering %K Solar %K treatment %K wood %X
We describe methods for creating solar-reflective nonwhite surfaces and their application to a wide variety of residential roofing materials, including metal, clay tile, concrete tile, wood, and asphalt shingle. Reflectance in the near-infrared (NIR) spectrum (0.7-2.5 μm) is maximized by coloring a topcoat with pigments that weakly absorb and (optionally) strongly backscatter NIR radiation, and by adding an NIR-reflective basecoat (e.g., one colored with titanium dioxide rutile white) if both the topcoat and the substrate weakly reflect NIR radiation. Coated steel and glazed clay-tile roofing products achieved NIR reflectances of up to 0.50 and 0.75, respectively, using only cool topcoats. Gray-cement concrete tiles achieved NIR reflectances as high as 0.60 with coatings colored by NIR-scattering pigments. Such tiles could attain NIR reflectances of up to 0.85 by overlaying a white basecoat with a topcoat colored by NIR-transparent organic pigments. Granule-surfaced asphalt shingles achieved NIR reflectances as high as 0.45 when the granules were covered with a white basecoat and a cool color topcoat.%B Solar Energy Materials and Solar Cells %V 91 %P 304-314 %8 02/2007 %G eng %N 4 %& 304 %R 10.1016/j.solmat.2006.06.062 %0 Conference Paper %B NFRC Conference %D 2007 %T NFRC Interlaboratory Comparison on Optical Properties %A Jacob C. Jonsson %A Michael D. Rubin %X
As part of the NFRC rating process, optical data on glazing materials is combined with other information to calculate various properties of a window product. The administrative procedure for gathering such optical data is governed by NFRC 3021, which in turn refers to NFRC 3002 and NFRC 3013 for the technical procedures by which the optical properties are determined in the solar and infrared ranges, respectively. In practice, the data is compiled by the Lawrence Berkeley National Laboratory (LBNL) and becomes part of the International Glazing Database (IGDB).
NFRC 302 specifies that submitters of optical data or their representatives must participate in a 'round robin' or ILC. Often, manufacturers of glazing materials have the optical equipment necessary to perform their own measurements. NFRC 302 allows manufacturers to submit their own measured data subject to a set of checks including peer review to ensure the accuracy of such data. In some cases the glazing manufacturer does not have the required equipment and so may choose to send the samples to a test laboratory. In other cases the manufacturer of the final product such as a laminate may ask a component supplier, often a glass manufacturer, to perform the measurements for them. In such cases the "representative" must have qualified by participating in the ILC. An ILC is only required every four years and it would be unfair to expect new product submitters to wait so long. Therefore, two interpretations are made on occasion: (1) a new data submitter does not have to wait for the next ILC if they submit a set of samples with their first dataset for comparison at LBNL (a mini ILC), or (2) if they have participated in an ILC conducted by some other reputable independent organization.%B NFRC Conference %C San Diego, CA %8 03/2006 %G eng %L LBNL-501E %1
Windows and Daylighting Group%2 LBNL-501E %0 Journal Article %J HVAC&R Research %D 2007 %T Review of Residential Ventilation Technologies %A Marion L. Russell %A Max H. Sherman %A Armin F. Rudd %X
This paper reviews current and potential ventilation technologies for residential buildings in North America and a few in Europe. The major technologies reviewed include a variety of mechanical systems, natural ventilation, and passive ventilation. Key parameters that are related to each system include operating costs, installation costs, ventilation rates, heat recovery potential. It also examines related issues such as infiltration, duct systems, filtration options, noise, and construction issues. This report describes a wide variety of systems currently on the market that can be used to meet ASHRAE Standard 62.2. While these systems generally fall into the categories of supply, exhaust or balanced, the specifics of each system are driven by concerns that extend beyond those in the standard and are discussed. Some of these systems go beyond the current standard by providing additional features (such as air distribution or pressurization control). The market will decide the immediate value of such features, but ASHRAE may wish to consider modifications to the standard in the future.%B HVAC&R Research %V 13 %P 325-348 %G eng %U http://www.tandfonline.com/doi/ref/10.1080/10789669.2007.10390957 %N 2 %1
2.3%2 LBNL-57730 %& 325 %0 Conference Paper %B 2006 ACEEE Summer Study on Energy Efficiency in Buildings %D 2006 %T Appliances, Lighting, Electronics, and Miscellaneous Equipment Electricity Use in New Homes %A Richard E. Brown %A William Rittelmann %A Danny S. Parker %A Gregory K. Homan %B 2006 ACEEE Summer Study on Energy Efficiency in Buildings %I Washington, DC: American Council for an Energy Efficient Economy %C Asilomar, CA %V 9 %P 9-37: 9-48 %8 08/2006 %G eng %2 LBNL-62440 %6 12 %0 Conference Proceedings %B 2006 ACEEE Summer Study on Energy Efficiency in Buildings %D 2006 %T Assessment of the Technical Potential for Achieving Zero-Energy Commercial Buildings %A Brent T. Griffith %A Paul A. Torcellini %A John Ryan %B 2006 ACEEE Summer Study on Energy Efficiency in Buildings %8 08/2006 %G eng %0 Conference Paper %B Fifteenth Symposium on Improving Building Systems in Hot and Humid Climates, July 24-26, 2006 %D 2006 %T Dehumidification Enhancement of Direct Expansion Systems through Component Augmentation of the Cooling Coil %A Douglas Kosar %A Don Shirey %A Mangesh Basarkar %A Muthasamy Swami %A Richard Raustad %X
Diverse air conditioning products with enhanced dehumidification features are being introduced to meet the increased moisture laden ventilation air requirements of ASHRAE Standard 62 in humid climates. In this evaluation, state point performance spreadsheet models for single path, mixed air packaged systems compare a conventional "off the shelf" direct expansion (DX) cooling system and its performance to systems that augment the DX coil with enhanced dehumidification components, such as heat exchangers and desiccant dehumidifiers. Using common performance metrics for comparisons at ARI rating conditions, these alternative systems define a best practice for enhanced dehumidification performance. The state point performance spreadsheet models combine available algorithms from the EnergyPlus™ simulation program for DX coils and heat exchangers with newly developed algorithms for desiccant dehumidifiers. All the models and their algorithms are applied in EnergyPlus™ for simulations of annual system cooling performance, including sensible and latent loads met, energy consumed, and humidity levels maintained, in select building types and climatic locations. Per this EnergyPlus™ analysis, these enhanced dehumidification systems present challenging decision-making tradeoffs between humidity control improvements over conventional DX systems, condensing (compressor) unit energy consumption reductions versus DX cool and reheat approaches, and fan energy use increases due to the additional component pressure drops.%B Fifteenth Symposium on Improving Building Systems in Hot and Humid Climates, July 24-26, 2006 %C Orlando, FL %G eng %0 Conference Proceedings %B SimBuild 2006 %D 2006 %T Low Energy Cooling Technologies for Sub-Tropical/Warm Humid Climate Building Systems %A Ashfaque Ahmed Chowdhury %A Mohammad Golam Rasul %A Mohammad Masud Kamal %B SimBuild 2006 %C Cambridge, MA, USA %8 08/2006 %G eng %0 Journal Article %J Solor Energy MaterialsSolar Energy Materials and Solar Cells %D 2006 %T Metal hydride switchable mirrors: Factors influencing dynamic range and stability %A Jonathan L. Slack %A James C.W. Locke %A Seung-Wan Song %A Jason Ona %A Thomas J. Richardson %K Metal hydrides %K Switchable mirrors %K thin films %X
Palladium-coated magnesium–manganese–nickel films behave as gasochromic switchable mirrors, becoming transparent on exposure to dilute hydrogen, and reverting to a mirror state on exposure to air. The cycling stability of the optical switching depends upon preservation of the integrity of the Pd catalyst overlayer. Alloying between Mg and Pd causes interdiffusion of the two elements, and leads to degradation in switching speed and eventual deactivation. Incorporation of a thin niobium oxide barrier layer between the active magnesium alloy film and the Pd layer substantially improves the cycling stability of the mirror.%B Solor Energy MaterialsSolar Energy Materials and Solar Cells %V 90 %P 485-490 %8 03/2006 %G eng %N 4 %& 485 %R 10.1016/j.solmat.2005.02.015 %F Batt %0 Conference Paper %B 2006 ACEEE Summer Study on Energy Efficiency in Buildings %D 2006 %T Space Heaters, Computers, Cell Phone Chargers: How Plugged In Are Commercial Buildings? %A Marla C. Sanchez %A Carrie A. Webber %A Richard E. Brown %A John F. Busch %A Margaret J. Pinckard %A Judy A. Roberson %B 2006 ACEEE Summer Study on Energy Efficiency in Buildings %I Washington, DC: American Council for an Energy Efficient Economy %C Asilomar, CA %V 9 %P 9-304: 9-315 %8 08/2006 %G eng %2 LBNL-62397 %6 12 %0 Journal Article %J Solar Energy %D 2005 %T Bi-Directional Transmission Properties of Venetian Blinds: Experimental Assessment Compared to Ray-Tracing Calculations %A Marilyn Andersen %A Michael D. Rubin %A Rebecca Powles %A Jean-Louis Scartezzini %X
An accurate evaluation of daylight distribution through advanced fenestration systems (complex glazing, solar shading systems) requires the knowledge of their Bidirectional light Transmission (Reflection) Distribution Function BT(R)DF. An innovative equipment for the experimental assessment of these bi-directional functions has been developed, based on a digital imaging detection system. An extensive set of BTDF measurements was performed with this goniophotometer on Venetian blinds presenting curved slats with a mirror coating on the upper side. In this paper, the measured data are compared with ray-tracing results achieved with a virtual copy of the device, that was constructed with a commercial ray-tracing software. The model of the blind was created by implementing the measured reflection properties of the slats coatings in the ray-tracing calculations. These comparisons represent an original and objective validation methodology for detailed bi-directional properties for a complex system; the good agreement between the two methods, yet presenting very different parameters and assessment methodologies, places reliance both on the digital-imaging detection system and calibration, and on the potentiality of a flexible calculation method combining ray-tracing simulations with simple components measurements.%B Solar Energy %V 78 %P 187-198 %G eng %L LBNL-58818 %1
Windows and Daylighting Group%2 LBNL-58818 %0 Report %D 2005 %T Evaluation of Alternative Field Buses for Lighting Control Applications %A Edward Koch %A Francis M. Rubinstein %X
This document is a report prepared in fulfillment of Task 1 of the Subcontract Statement of Work between Lawrence Berkeley National Laboratory and Broadata Communications, Inc. The statement of work that covers the requirements for this report is included in the following section.%G eng %L LBNL-57356 %1
Lighting Systems Group%2 LBNL-57356 %0 Conference Paper %B ASME International Mechanical Engineering Congress and Exposition, November 5-11, 2005 %D 2005 %T Experimental Determination of the Effect of Varying Base Fluid and Temperature on the Static Thermal Conductivity of Nanofluids %A S. Nara %A Prajesh Bhattacharya %A P. Vijayan %A W. Y. Lai %A W. Rosenthal %A Patrick E Phelan %A Ravi S. Prasher %A David W. Song %A Jinlin Wang %X
The heat transfer abilities of fluids can be improved by adding small particles of sizes of the order of nanometers. Recently a lot of research has been done in evaluating the thermal conductivity of nanofluids using various nanoparticles. In our present work we address this issue by conducting a series of experiments to determine the effective thermal conductivity of alumina-nanofluids by varying the base fluid with water and antifreeze liquids like ethylene glycol and propylene glycol. Temperature oscillation method is used to find the thermal conductivity of the nanofluid. The results show the thermal conductivity enhancement of nanofluids depends on viscosity of the base fluid. Finally the results are validated with a recently proposed theoretical model.%B ASME International Mechanical Engineering Congress and Exposition, November 5-11, 2005 %I ASME %C Orlando, FL %8 11/2005 %@ 0-7918-4221-5 %G eng %R 10.1115/IMECE2005-81494 %0 Conference Paper %B IBPSA Building Simulation 2005 %D 2005 %T Modeling Ground Source Heat Pump Systems in a Building Energy Simulation Program (EnergyPlus) %A Daniel E. Fisher %A Simon J. Rees %B IBPSA Building Simulation 2005 %C Montreal, canada %8 08/2005 %G eng %0 Journal Article %J Energy and Buildings %D 2005 %T Monitoring the energy-use effects of cool roofs on California commercial buildings %A Hashem Akbari %A Ronnen M. Levinson %A Leo I. Rainer %K california %K commercial buildings %K cool roof %K cool roofs %K energy %K envelope %K Heat Island %K monitoring %K peak demand %X
Solar-reflective roofs stay cooler in the sun than solar-absorptive roofs. Such "cool" roofs achieve lower surface temperatures that reduce heat conduction into the building and the building's cooling load. We monitored the effects of cool roofs on energy use and environmental parameters in six California buildings at three different sites: a retail store in Sacramento; an elementary school in San Marcos (near San Diego); and a four-building cold storage facility in Reedley (near Fresno). The latter included a cold storage building, a conditioning and fruit-palletizing area, a conditioned packing area, and two unconditioned packing areas.
Results showed that installing a cool roof reduced the daily peak roof surface temperature of each building by 33-42 K. In the retail store building in Sacramento, for the monitored period of 8 August-30 September 2002, the estimated savings in average air conditioning energy use was about 72 Wh/m2/day (52%). On hot days when the afternoon temperature exceeded 38 °C, the measured savings in average peak demand for peak hours (noon-5 p.m.) was about 10 W/m2 of conditioned area. In the school building in San Marcos, for the monitored period of 8 July-20 August 2002, the estimated savings in average air conditioning energy use was about 42-48 Wh/m2/day (17-18%). On hot days, when the afternoon temperature exceeded 32 °C, the measured savings in average peak demand for hours 10 a.m.-4 p.m. was about 5 W/m2 of conditioned area. In the cold storage facility in Reedley, for the monitored period of 11 July-14 September 2002, and 11 July-18 August 2003, the estimated savings in average chiller energy use was about 57-81 Wh/m2/day (3-4%). On hot days when the afternoon temperature exceeded 38 °C, the measured savings in average peak-period demand (average cooling-power demand during peak demand hours, typically noon-6 p.m.) was about 5-6 W/m2 of conditioned area.
Using the measured data and calibrated simulations, we estimated savings for similar buildings installing cool roofs in retrofit applications for all 16 California climate zones. For similar retail stores in climate zones 2 and 4-16, installing a cool roof can save about 6-15 kWh/m2/year of conditioned area. In climate zones 2-16, estimates of average peak demand savings for hours noon-5 p.m. range from 2.9 to 5.8 W/m2. For similar school buildings in climate zones 2-16, installing a cool roof can save from 3 to 6 kWh/m2/year of conditioned roof area. For all 16 climate zones estimates of average peak demand savings for hours noon-5 p.m. range from 2.6 to 3.8 W/m2. In similar cold storage buildings in all 16 climate zones, installing a cool roof can save about 4.5-7.4 kWh/m2/year of conditioned roof area. In all 16 climate zones, estimates of average peak demand savings for hours noon-5 p.m. range from 3.9 to 6.6 W/m2.%B Energy and Buildings %V 37 %P 1007-1016 %8 10/2005 %G eng %N 10 %& 1007 %R 10.1016/j.enbuild.2004.11.013 %0 Report %D 2004 %T After-hours Power Status of Office Equipment and Energy Use of Miscellaneous Plug-Load Equipment %A Judy A. Roberson %A Carrie A. Webber %A Marla C. McWhinney %A Richard E. Brown %A Margaret J. Pinckard %A John F. Busch %K Enduse %K Energy End-Use Forecasting %K EUF %X
This research was conducted in support of two branches of the EPA ENERGY STAR program, whose overall goal is to reduce, through voluntary market-based means, the amount of carbon dioxide emitted in the U.S. The primary objective was to collect data for the ENERGY STAR Office Equipment program on the afterhours power state of computers, monitors, printers, copiers, scanners, fax machines, and multi-function devices. We also collected data for the ENERGY STAR Commercial Buildings branch on the types and amounts of "miscellaneous" plug-load equipment, a significant and growing end use that is not usually accounted for by building energy managers. For most types of miscellaneous equipment, we also estimated typical unit energy consumption in order to estimate total energy consumption of the miscellaneous devices within our sample. This data set is the first of its kind that we know of, and is an important first step in characterizing miscellaneous plug loads in commercial buildings.
The main purpose of this study is to supplement and update previous data we collected on the extent to which electronic office equipment is turned off or automatically enters a low power state when not in active use. In addition, it provides data on numbers and types of office equipment, and helps identify trends in office equipment usage patterns. These data improve our estimates of typical unit energy consumption and savings for each equipment type, and enables the ENERGY STAR Office Equipment program to focus future effort on products with the highest energy savings potential.
This study expands our previous sample of office buildings in California and Washington DC to include education and health care facilities, and buildings in other states. We report data from sixteen commercial buildings in California, Georgia, and Pennsylvania: four education buildings, two medical buildings, two large offices (> 500 employees each), three medium offices (50-500 employees each), and five small business offices (< 50 employees each). Two buildings are in the San Francisco Bay area of California, nine (including the five small businesses) are in Pittsburgh, Pennsylvania, and five are in Atlanta, Georgia.%I Lawrence Berkeley National Laboratory %C Berkeley, CA %P 38 %8 05/2004 %@ LBNL-53729-Revised %G eng %2 LBNL-53729R %0 Journal Article %D 2004 %T After-hours Power Status of Office Equipment and Inventory of Miscellaneous Plug-Load Equipment %A Judy A. Roberson %A Carrie A. Webber %A Marla C. McWhinney %A Richard E. Brown %A Margaret J. Pinckard %A John F. Busch %K Enduse %K Energy End-Use Forecasting %K EUF %X
This research was conducted in support of two branches of the EPA ENERGY STAR program, whose overall goal is to reduce, through voluntary market-based means, the amount of carbon dioxide emitted in the U.S. The primary objective was to collect data for the ENERGY STAR Office Equipment program on the afterhours power state of computers, monitors, printers, copiers, scanners, fax machines, and multi-function devices. We also collected data for the ENERGY STAR Commercial Buildings branch on the types and amounts of "miscellaneous" plug-load equipment, a significant and growing end use that is not usually accounted for by building energy managers. This data set is the first of its kind that we know of, and is an important first step in characterizing miscellaneous plug loads in commercial buildings.
The main purpose of this study is to supplement and update previous data we collected on the extent to which electronic office equipment is turned off or automatically enters a low power state when not in active use. In addition, it provides data on numbers and types of office equipment, and helps identify trends in office equipment usage patterns. These data improve our estimates of typical unit energy consumption and savings for each equipment type, and enables the ENERGY STAR Office Equipment program to focus future effort on products with the highest energy savings potential.
This study expands our previous sample of office buildings in California and Washington DC to include education and health care facilities, and buildings in other states. We report data from twelve commercial buildings in California, Georgia, and Pennsylvania: two health care buildings, two large offices (> 500 employees each), three medium offices (50-500 employees), four education buildings, and one "small office" that is actually an aggregate of five small businesses. Two buildings are in the San Francisco Bay area of California, five are in Pittsburgh, Pennsylvania, and five are in Atlanta, Georgia.%I Lawrence Berkeley National Laboratory %C Berkeley, CA %P 33 %8 01/2004 %@ LBNL-53729 %G eng %2 LBNL-53729 %0 Journal Article %J Journal of Applied Physics %D 2004 %T Charge-State-Resolved Ion Energy Distributions of Aluminum Vacuum Arcs %A Johanna Rosén %A André Anders %A Stanislav Mráz %A Jochen M. Schneider %X
The charge-state-resolved ion energy distributions of metal ions present in a cathodic arc plasma have been measured and analyzed. Contrary to literature data, lower energies were observed for higher charged ions. The observations were explained by opposing acceleration by pressure gradient and electron-ion coupling, and deceleration by part of the discharge voltage. The distributions were well fitted by shifted Maxwellian distributions, giving additional information on plasma parameters. These results are of importance for an improved understanding of the evolution of ion energy distributions, and is hence instrumental for future progress in thin film growth modelling.%B Journal of Applied Physics %V 97 %G eng %1
Windows and Daylighting Group%2 LBNL-56327 %0 Conference Paper %B ACEEE Summer Study on Energy Efficiency in Buildings, August 22-27, 2004 %D 2004 %T Cool colored roofs to save energy and improve air quality %A Hashem Akbari %A Paul H. Berdahl %A Ronnen M. Levinson %A Stephen Wiel %A Andre Desjarlais %A William A. Miller %A Nancy Jenkins %A Arthur H. Rosenfeld %A Chris Scruton %K cool roof %K Heat Island %X
Raising the solar reflectance of a roof from a typical value of 0.1 – 0.2 to an achievable 0.6 can reduce cooling-energy use in buildings by more than 20%. Cool roofs also reduce ambient outside air temperature, thus further decreasing the need for air conditioning and retarding smog formation.
We are collaborating with pigment manufacturers to characterize colorants, and with manufacturers of roofing materials to produce cool colored products, including asphalt shingles, tiles, metal roofing, wood shakes, membranes, and coatings. Significant efforts are being devoted to the identification and characterization of pigments suitable for cool-colored coatings, and to the development of engineering methods for applying cool coatings to roofing materials. We are also measuring and documenting the laboratory and in-situ performances of roofing products. Demonstration of energy savings can accelerate the market penetration of cool-colored roofing materials. Early results from this program have yielded colored concrete, clay, and metal roofing products with solar reflectances exceeding 0.4. Obtaining equally high reflectances for roofing shingles is more challenging, but we expect manufacturers to soon have several cost-effective colored shingles with reflectances of at least 0.25.%B ACEEE Summer Study on Energy Efficiency in Buildings, August 22-27, 2004 %7 1 %I American Council for an Energy-Efficient Economy %V 1 %P 1-16 %8 08/2004 %G eng %U http://aceee.org/proceedings-paper/ss04/panel01/paper01 %6 11 %0 Journal Article %D 2004 %T Field Power Measurements of Imaging Equipment %A Marla C. McWhinney %A Gregory K. Homan %A Richard E. Brown %A Judy A. Roberson %A Bruce Nordman %A John F. Busch %K Enduse %K Energy End-Use Forecasting %K EUF %X
According to the U.S. Department of Energy, electricity use by non-PC commercial office equipment is growing at an annual rate of nearly 5% (AEO 2003). To help address this growth in consumption, U.S. EPA periodically updates its ENERGY STAR specifications as products and markets change. This report presents background research conducted to help EPA update the ENERGY STAR specification for imaging equipment, which covers printers, fax machines, copiers, scanners, and multifunction devices (MFDs). We first estimated the market impact of the current ENERGY STAR imaging specification, finding over 90% of the current market complies with the specification. We then analyzed a sample of typical new imaging products, including 11 faxes, 57 printers and 19 copiers/MFD. For these devices we metered power levels in the most common modes: active/ready/sleep/off, and recorded features that would most likely affect energy consumption. Our metering indicates that for many products and speed bins, current models consume substantially less power than the current specification. We also found that for all product categories, power consumption varied most considerably across technology (i.e. inkjet vs. laser). Although inkjet printers consumed less energy than laser printers in active, ready and sleep-mode, they consumed more power on average while off, mostly due to the use of external power supplies. Based on these findings, we developed strategies for the ENERGY STAR program to achieve additional energy reductions. Finally, we present an assessment of manufacturer's ENERGY STAR labeling practices.%I Lawrence Berkeley National Laboratory %C Berkeley, CA %8 05/2004 %@ LBNL-54202 %G eng %2 LBNL-54202 %0 Report %D 2004 %T Hardware/Software Solution Unifying DALI, IBECS, and BACnet Final Report %A Edward Koch %A Francis M. Rubinstein %A Sila Kiliccote %X
The goal of this project was to investigate broader building-level systems/strategies that enable further energy savings and control. This project investigated the potential savings offered by broader centralized control features and the potential advantages they may add to this system through such features as addressability and load shedding. This report documents the results of LBNL's work in this area.
This report focuses on building-level systems and strategies and a multi-protocol gateway solution that is indifferent to the specific choice of lighting control/communications technique used to control the office lighting. The elegance of the IEEE 1451 intelligent gateway proposed in this report is that the overall building communications system should work regardless of whether the office lighting is controlled by DALI, UPB, IBECS, ZigBee or any other accepted communications protocol.%G eng %L LBNL-57686 %1
Lighting Systems Group%2 LBNL-57686 %0 Journal Article %J Energy and Buildings %D 2004 %T Low-Cost Networking for Dynamic Window Systems %A Eleanor S. Lee %A Dennis L. DiBartolomeo %A Francis M. Rubinstein %A Stephen E. Selkowitz %X
A low-cost building communications network is needed that would allow individual window and lighting loads to be controlled fromsan existing enterprise LAN network. This building communications network concept, which we term Integrated Building EnvironmentalsCommunications System (IBECSTM), would enable both occupant-based and building-wide control of individual window, lighting, andssensor devices. IBECS can reduce the cost of systemic control because it allows a drastic cost reduction in per point networking costs. This kind of effort is needed to encourage the control industry to make the commitment to build this technology and to demonstratesto prospective customers that this breakthrough approach to more comprehensive systemic control will provide them with high-quality,sconvenient control while saving them money.
The development and demonstration of network interfaces to DC- and AC-motorized shades and to an electrochromic window aresdescribed. The network interfaces enable one to control and monitor the condition of these fenestration appliances from a variety of sources,sincluding a user?s personal computer. By creating a functional specification for an IBECS network interface and testing a prototype, thesability to construct such an interface was demonstrated and the cost-effective price per point better understood. The network interfacesswere demonstrated to be reliable in a full-scale test of three DC-motorized Venetian blinds in an open-plan office over 2 years and in limitedsbench-scale tests of an electrochromic window.%B Energy and Buildings %V 36 %P 503-513 %G eng %L LBNL-52198 %1
Windows and Daylighting Group%2 LBNL-52198 %0 Report %D 2004 %T Performance of Powerline-Controlled Luminaire Final Report %A Francis M. Rubinstein %A Pete Pettler %A Joel Snook %A Erik Engelking %A Sila Kiliccote %X
In previous work, LBNL with Vistron Corp, developed an innovative lighting control system using a communications technology called Phase Cut Carrier (PCC). This report describes the performance of the desktop demonstration system that was developed to test this new controls concept. More detailed information on this project is given. This report is in fulfillment of deliverable #1 "Report on Performance of Powerline-carrier Controlled Luminaire" from the FY2004 DOE Work Plan.%G eng %L LBNL-57687 %1
Lighting Systems Group%2 LBNL-57687 %0 Conference Paper %B CIE Session 2003 %D 2003 %T Analyzing Occupancy Profiles from a Lighting Controls Field Study %A Francis M. Rubinstein %A Nesrin Colak %A Judy D. Jennings %A Danielle Neils %X
Despite a number of published studies on the effectiveness of lighting controls in buildings, only one US study examines the occupancy patterns of building occupants. Occupancy profiles allow one to determine, for example, the probability that an office is occupied for each hour of the workday. Occupancy profiles are useful for many purposes including: 1) predicting the effectiveness of occupancy sensors for reducing peak demand, 2) evaluating the impact of human activity on building lighting and other electric loads and 3) providing lighting equipment manufacturers with detailed lighting operation data to help evaluate the impact of advanced lighting controls on equipment life. In this paper, we examine the occupancy profiles for 35 single person offices at a large office building in San Francisco and analyze the data to obtain average occupancy as a function of time of day. In addition, we analyzed the data to identify how the use of occupancy sensors may affect switching cycles and lamp life.%B CIE Session 2003 %C San Diego, CA %8 06/2003 %G eng %L LBNL-52344 %1
Lighting Systems Group%2 LBNL-52344 %0 Journal Article %J Landscape and Urban Planning %D 2003 %T Analyzing the land cover of an urban environment using high-resolution orthophotos %A Hashem Akbari %A Leanna S. Rose %A Haider Taha %K Analyzing high-resolution orthophotos %K Heat Island %K urban fabric %K urban heat island %K Urban LULC %X
To estimate the impact of light-colored surfaces (roofs and pavements) and urban vegetation (trees, grass, shrubs) on meteorology and air quality of a city, it is essential to accurately characterize various urban surfaces. Of particular importance is the characterization of the area fraction of various surface-types as well as the vegetative fraction. In this paper, a method is discussed for developing data on surface-type distribution and city-fabric (land cover) makeup (percentage of various surface-types) using high-resolution orthophtos. We devised a semi-automatic Monte Carlo method to sample the data and visually identify the surface-type for each pixel. The color aerial photographs for Sacramento covered a total of about 65 km2, at 0.3-m resolution.
Five major land-use types were examined: (1) downtown and city center, (2) industrial, (3) offices, (4) commercial, and (5) residential. In downtown Sacramento, the top view (above-the-canopy) shows that vegetation covers 30% of the area, whereas roofs cover 23% and paved surfaces (roads, parking areas, and sidewalks) 41%. In the industrial areas, vegetation covers 8–14% of the area, whereas roofs cover 19–23%, and paved surfaces 29–44%. The surface-type percentages in the office area were 21% trees, 16% roofs, and 49% paved areas. In commercial areas, vegetation covers 5–20%, roofs 19–20%, paved surfaces 44–68%. Residential areas exhibit a wide range of percentages among their various surface-types. On average, vegetation covers about 36% of the area, roofs about 20%, and paved surfaces about 28%. Trees mostly shade streets, parking lots, grass, and sidewalks. In most non-residential areas, paved surfaces cover 50–70% of the under-the-canopy area. In residential areas, on average, paved surfaces cover about 35% of the area.
Land-use/land cover (LULC) data from the United States Geological Survey (USGS) was used to extrapolate these results from neighborhood scales to metropolitan Sacramento. Of an area of roughly 800 km2, defining most urban areas of the metropolitan Sacramento, about half is residential. The total roof area comprises about 150 km2 and the total paved surfaces (roads, parking areas, sidewalks) are about 310 km2. The total vegetated area covers about 230 km2. The remaining 110 km2 consist of barren land and miscellaneous surfaces.%B Landscape and Urban Planning %V 63 %P 1-14 %8 03/2003 %G eng %N 1 %& 1 %R 10.1016/S0169-2046(02)00165-2 %0 Report %D 2003 %T Characterizing the fabric of the urban environment: a case study of greater Houston, Texas %A Leanna S. Rose %A Hashem Akbari %A Haider Taha %K Case Studies %K Heat Island %X
In this report, the materials and various surface types that comprise a city are referred to as the "urban fabric". Urban fabric data are needed in order to estimate the impact of light-colored surfaces (roofs and pavements) and urban vegetation (trees, grass, shrubs) on the meteorology and air quality of a city, and to design effective urban-environmental implementation programs. We discuss the results of a semi-automatic Monte-Carlo statistical approach used to develop data on surface-type distribution and city-fabric makeup (percentage of various surface-types) using aerial color orthophotography. The digital aerial photographs for Houston covered a total of about 52 km2 (20 mi2). At 0.30-m resolution, there were approximately 5.8 x 108 pixels of data.
Four major land-use types were examined: (1) commercial, (2) industrial, (3) educational, and (4) residential. On average, for the regions studied, vegetation covers about 39% of the area, roofs cover about 21%, and paved surfaces cover about 29%. For the most part, trees shade streets, parking lots, grass, and sidewalks. At ground level, i.e., view from below the vegetation canopies, paved surfaces cover about 32% of the study area.
GLOBEIS model data from University of Texas and land-use/land-cover (LULC) information from the United States Geological Survey (USGS) were used to extrapolate these results from neighborhood scales to Greater Houston. It was found that in an area of roughly 3,430 km2, defining most of Greater Houston, over 56% is residential. The total roof area is about 740 km2, and the total paved surface area (roads, parking areas, sidewalks) covers about 1000 km2. Vegetation covers about 1,320 km2.%8 01/2003 %G eng %U http://repositories.cdlib.org/lbnl/LBNL-51448 %2 LBNL-51448 %0 Journal Article %J Transportation Research Part D %D 2003 %T Comment on ''Statistical modelling of vehicle emissions from inspection/maintenance testing data: an explanatory analysis'' %A Thomas P. Wenzel %A Marc Ross %B Transportation Research Part D %V 8 %P 69-71 %8 01/2003 %G eng %N 1 %2 LBNL-48061 %& 69 %R 10.1016/S1361-9209(02)00009-3 %0 Journal Article %J Solar Energy %D 2003 %T Comparison Between Ray-Tracing Simulations and Bi-Directional Transmission Measurements on Prismatic Glazing %A Marilyn Andersen %A Michael D. Rubin %A Jean-Louis Scartezzini %X
Evaluation of solar heat gain and daylight distribution through complex window and shading systems requires the determination of the bi-directional transmission distribution function (BTDF). Measurement of BTDF can be timeconsuming, and inaccuracies are likely because of physical constraints and experimental adjustments. A general calculation methodology, based on more easily measurable component properties, would be preferable and would allow much more flexibility. In this paper, measurements and calculations are compared for the specific case of prismatic daylight-redirecting panels. Measurements were performed in a photogoniometer equipped with a digital-imaging detection system. A virtual copy of the photogoniometer was then constructed with commercial ray-tracing software. For the first time, an attempt is made to validate detailed bi-directional properties for a complex system by comparing an extensive set of experimental BTDF data with ray-tracing calculations. The results generally agree under a range of input and output angles to a degree adequate for evaluation of glazing systems. An analysis is presented to show that the simultaneously measured diffuse and direct components of light transmitted by the panel are properly represented. Calculations were also performed using a more realistic model of the source and ideal model of the detector. Deviations from the photogoniometer model were small and the results were similar in form. Despite the lack of an absolute measurement standard, the good agreement in results promotes confidence in both the photogoniometer and in the calculation method.%B Solar Energy %V 74 %P 157-173 %8 02/2003 %G eng %N 2 %1
Windows and Daylighting Group%2 LBNL-51169 %& 157 %R 10.1016/S0038-092X(03)00115-4 %0 Conference Paper %B DIGITAL DESIGN - 22nd International eCAADe Conference %D 2003 %T Decision-Making Through Performance Simulation and Code Compliance from the Early, Schematic Phases of Building Design %A Georg Reichard %A Konstantinos M. Papamichael %X
This paper is about the merging of two software applications that allows building decision makers to consider code compliance and to use performance simulation tools from the early, schematic phases of building design. By making the capabilities of a code compliance tool available at the early schematic phases of building design, the hope and expectation is that users will use this software to address the mandatory code compliance issues and thus have an opportunity to address other performance issues as well.%B DIGITAL DESIGN - 22nd International eCAADe Conference %C Graz, Austria %8 06/2003 %G eng %L LBNL-52964 %2 LBNL-52964 %3
September 17-20, 2003%#
Commercial Building Systems%]
y%0 Report %D 2003 %T Draft Photosensor Characterization Report %A Francis M. Rubinstein %A Mehry Yazdanian %A Jim Galvin %X
This report presents the results of laboratory measurements performed on The Watt Stopper's LS-201 photosensor at the Lawrence Berkeley National Laboratory in January, 2003. The purpose of these measurements was to characterize the spatial and spectral response function of the LS-201 photosensor. This work was performed in fulfillment of a Project 3.3 Deliverable for the California Energy Commission's Lighting Research Program.
The report has three sections. The first section describes the measurements performed to determine the spectral response function (sensitivity to light of different wavelengths) of the photosensor. The second section presents the results of our measurements of the sensitivity of the photosensor to light from different directions — the spatial response function. The third section presents our conclusions and preliminary suggestions for product improvement consistent with project goals and objectives.%G eng %L LBNL-56152 %1
Lighting Systems Group%2 LBNL-56152 %0 Conference Paper %B DIGITAL DESIGN - 22nd International eCAADe Conference %D 2003 %T Instructor: Let the Experts Guide the Use of Simulation Software %A Georg Reichard %A Adil Al-Mumin %A Konstantinos M. Papamichael %X
A new guidance concept is presented, which encourages third parties, like educators, to provide additional, comprehensive information to users of highly complex (e.g. simulation-) software, helping them to flatten the steep learning curve by understanding the impact of decisions made during the input/design process.%B DIGITAL DESIGN - 22nd International eCAADe Conference %C Graz, Austria %8 06/01/2003 %G eng %L LBNL-52965 %2 LBNL-52965 %3
September 17-20, 2003%#
Commercial Building Systems Group%]
y%0 Conference Paper %B 203rd Meeting of the Electrochemical Society %D 2003 %T Lithium-Based Electrochromic Mirrors %A Thomas J. Richardson %A Jonathan L. Slack %X
Antimony, antimony-copper, and antimony-silver thin films were prepared by DC magnetron sputtering on glass substrates. Their reflectance and transmittance in the visible range were measured before and after electrochemical lithiation. The mixed metal films exhibited larger changes in reflectance and small shifts in the optical absorption edge compared with pure antimony films. Electrochromic cycling speed and stability of the Sb-Li system were improved by the addition of copper and silver.%B 203rd Meeting of the Electrochemical Society %C Paris, France %8 04/2003 %G eng %L LBNL-52870 %1
Windows and Daylighting Group%2 LBNL-52870 %0 Conference Paper %B 2003 IEEE-IAS Conference %D 2003 %T Standardizing Communication Between Lighting Control Devices %A Francis M. Rubinstein %A Stephen Treado %A Pete Pettler %K BACnet %K building controls %K building equipment %K communication protocols %K DALI %K IBECS %K IEEE P1451 %K lighting controls %K networking %X
Integrated lighting controls can significantly improve building performance, increase energy efficiency, and enhance occupant comfort and satisfaction with the built environment. While previous research has shown that simple lighting controls such as occupancy sensors are effective at reducing the amount of electrical energy used for lighting in commercial buildings, advanced lighting control strategies have the potential to achieve even greater energy savings and offer many advantages over simple controls. But more advanced control strategies, such as daylighting or load shedding, which require a more systems-oriented approach, were less successful. Some of these difficulties are a result of the horizontal structure of the U.S. lighting controls market. While there are notable exceptions, the market is comprised largely of manufacturers of components (ballasts, switches and controls devices) rather than systems. Lighting controls components often do not work well together when specified as systems, especially in dimming applications where wiring is more elaborate. Lighting control equipment for implementing more complex strategies such as daylighting has proven difficult to commission in the field, leading to poor operation and user complaints. Finally, the lack of agreement on communications protocols was identified in as another market barrier.%B 2003 IEEE-IAS Conference %C Salt Lake City, UT %G eng %1
Lighting Systems Group%2 LBNL-53000 %0 Journal Article %J Applied Optics %D 2002 %T Aging of reflective roofs: soot deposition %A Paul H. Berdahl %A Hashem Akbari %A Leanna S. Rose %K cool roof %K Heat Island %B Applied Optics %V 41 %P 2355-2360 %G eng %U http://ao.osa.org/abstract.cfm?URI=ao-41-12-2355 %0 Report %D 2002 %T An Analysis of Traffic Deaths by Vehicle Type and Model %A Thomas P. Wenzel %A Marc Ross %X
This study compares the risk of death in traffic accidents, depending on type of vehicle and vehicle model. Here, risk is driver deaths per year per million vehicle sales, for model years 1995–1999. Two risks are evaluated: the risk to the driver of the vehicle model in question in all types of crashes and the risk to the drivers of other vehicles involved in crashes with the model in question. The sum of those risks is the combined risk. Our main results are that sport utility vehicles (SUVs) are not necessarily safer for their drivers than cars; on average they are as risky as the average midsize or large car, and no safer than many of the most popular compact and subcompact models. Minivans and import luxury cars have the safest records. If combined risk is considered, most cars are safer than the average SUV, while pickup trucks are much less safe than all other types. Characteristics of the drivers of certain vehicle types probably have a strong effect on safety. For example, sports cars as driven are extremely risky for their drivers, who tend to be young males, and minivans are extremely safe for their drivers, very few of whom are young males. However, there is no evidence that driver age and sex distributions increase the risk of the average SUV compared to the risk of the average midsize car or a safe smaller car model.%8 03/2002 %G eng %2 LBNL-49675 %0 Journal Article %J Journal of Applied Physics %D 2002 %T Calculation of Thermodynamic, Electronic, and Optical Properties of Monoclinic Mg2NiH4 %A Whittier R. Myers %A Lin-Wang Wang %A Thomas J. Richardson %A Michael D. Rubin %X
Ab initio total-energy density functional theory is used to investigate the low temperature (LT) monoclinic form of Mg2NiH4. The calculated minimum energy geometry of LT Mg2NiH4 is close to that determined from neutron diffraction data, and the NiH4 complex is close to a regular tetrahedron. The enthalpies of the phase change to high temperature (HT) pseudo-cubic Mg2NiH4 and of hydrogen absorption by Mg2Ni are calculated and compared with experimental values. LT Mg2NiH4 is found to be a semiconductor with an indirect band gap of 1.4 eV. The optical dielectric function of LT Mg2NiH4 differs somewhat from that of the HT phase. A calculated thin film transmittance spectrum is consistent with an experimental spectrum.%B Journal of Applied Physics %V 91 %P 4879-4885 %8 04/2002 %G eng %N 8 %1
Windows and Daylighting Group%2 LBNL-47519 %& 4879 %R 10.1063/1.1454206 %0 Conference Paper %B 2002 ACEEE Summer Study on Energy Efficiency in Buildings %D 2002 %T Dimming Every Light Cheaply %A Francis M. Rubinstein %A Pete Pettler %A Judy D. Jennings %X
This paper discusses the successful development and testing of the first ballast/IBECS network interface that will allow commercially-available controllable ballasts to be operated from the Internet via IBECS (Integrated Building Environmental Communications System). The interface, which is expected to cost original equipment manufacturers (OEMs) only about $1-2/unit, has been hardened so that it is impervious to electronic noise generated by most 0-10 VDC controllable ballasts.%B 2002 ACEEE Summer Study on Energy Efficiency in Buildings %C Pacific Grove, California %V 11 %8 08/2002 %G eng %L LBNL-49975 %1
Lighting Systems Group%2 LBNL-49975 %0 Report %D 2002 %T Energy Performance Analysis of Electrochromic Windows in New York Commercial Office Buildings %A Eleanor S. Lee %A L. Zhou %A Mehry Yazdanian %A Vorapat Inkarojrit %A Jonathan L. Slack %A Michael D. Rubin %A Stephen E. Selkowitz %X
A DOE-2.1E energy simulation analysis of a switchable electrochromic (EC) glazing with daylighting controls has been conducted for prototypical office buildings in New York (NY). The modeling included four types of office buildings: "old" and "new" vintages and large (10,405 m2, 112,000 ft2) and small (502m2, 5400 ft2) buildings. Five commercially available, base case windows with and without interior shades were modeled. Window area varied from 0 to 60% of the exterior floor-to-floor wall area. The electric lighting had either no controls or continuous daylighting controls. The prototypes were modeled in New York City or Buffalo.
Energy performance ata are given for each of the four perimeter zones. Data are presented as a function of window-to-wall ratio in order to better understand the interactions between 1) electric lighting energy use and daylight admission and 2) solar heat gains and space-conditioning energy use. Maximum and minimum reductions in energy use between the EC glazing and all other base case conditions are also presented. Projected energy use reductions relative to typical specified NY office buildings are presented as an indication of the potential impacts EC glazings might have in retrofit and new construction.
The energy and demand reductions provided by EC glazings with daylighting controls relative to what is typically specified in office buildings in NY are quite substantial. EC glazings will also dampen fluctuations in interior daylight levels and window brightness, potentially increasing visual comfort.%8 11/2002 %G eng %1
Windows and Daylighting Group%2 LBNL-50096 %0 Report %D 2002 %T Energy Use and Power Levels in New Monitors and Personal Computers %A Judy A. Roberson %A Gregory K. Homan %A Akshay Mahajan %A Bruce Nordman %A Carrie A. Webber %A Richard E. Brown %A Marla C. McWhinney %A Jonathan G. Koomey %K Enduse %K Energy End-Use Forecasting %K EUF %X
Our research was conducted in support of the EPA ENERGY STAR Office Equipment program, whose goal is to reduce the amount of electricity consumed by office equipment in the U.S. The most energy-efficient models in each office equipment category are eligible for the ENERGY STAR label, which consumers can use to identify and select efficient products. As the efficiency of each category improves over time, the ENERGY STAR criteria need to be revised accordingly.
The purpose of this study was to provide reliable data on the energy consumption of the newest personal computers and monitors that the EPA can use to evaluate revisions to current ENERGY STAR criteria as well as to improve the accuracy of ENERGY STAR program savings estimates. We report the results of measuring the power consumption and power management capabilities of a sample of new monitors and computers. These results will be used to improve estimates of program energy savings and carbon emission reductions, and to inform revisions of the ENERGY STAR criteria for these products.
Our sample consists of 35 monitors and 26 computers manufactured between July 2000 and October 2001; it includes cathode ray tube (CRT) and liquid crystal display (LCD) monitors, Macintosh and Intelarchitecture computers, desktop and laptop computers, and integrated computer systems, in which power consumption of the computer and monitor cannot be measured separately. For each machine we measured power consumption when off, on, and in each low-power level. We identify trends in and opportunities to reduce power consumption in new personal computers and monitors.
Our results include a trend among monitor manufacturers to provide a single very low low-power level, well below the current ENERGY STAR criteria for sleep power consumption. These very low sleep power results mean that energy consumed when monitors are off or in active use has become more important in terms of contribution to the overall unit energy consumption (UEC). Current ENERGY STAR monitor and computer criteria do not specify off or on power, but our results suggest opportunities for saving energy in these modes. Also, significant differences between CRT and LCD technology, and between field-measured and manufacturer-reported power levels reveal the need for standard methods and metrics for measuring and comparing monitor power consumption.%I Lawrence Berkeley National Laboratory %C Berkeley, CA %8 07/2002 %@ LBNL-48581 %G eng %2 LBNL-48581 %0 Report %D 2002 %T Enery Use and Power Management in New Personal Computers and Monitors %A Judy A. Roberson %A Gregory K. Homan %A Akshay Mahajan %A Bruce Nordman %A Carrie A. Webber %A Richard E. Brown %A Marla C. McWhinney %A Jonathan G. Koomey %X
Our research was conducted in support of the EPA ENERGY STAR Office Equipment program, whose goal is to reduce the amount of electricity consumed by office equipment in the U.S. The most energy-efficient models in each office equipment category are eligible for the ENERGY STAR label, which consumers can use to identify and select efficient products. As the efficiency of each category improves over time, the ENERGY STAR criteria need to be revised accordingly.
The purpose of this study was to provide reliable data on the energy consumption of the newest personal computers and monitors that the EPA can use to evaluate revisions to current ENERGY STAR criteria as well as to improve the accuracy of ENERGY STAR program savings estimates. We report the results of measuring the power consumption and power management capabilities of a sample of new monitors and computers. These results will be used to improve estimates of program energy savings and carbon emission reductions, and to inform revisions of the ENERGY STAR criteria for these products.
Our sample consists of 35 monitors and 26 computers manufactured between July 2000 and October 2001; it includes cathode ray tube (CRT) and liquid crystal display (LCD) monitors, Macintosh and Intelarchitecture computers, desktop and laptop computers, and integrated computer systems, in which power consumption of the computer and monitor cannot be measured separately. For each machine we measured power consumption when off, on, and in each low-power level. We identify trends in and opportunities to reduce power consumption in new personal computers and monitors.
Our results include a trend among monitor manufacturers to provide a single very low low-power level, well below the current ENERGY STAR criteria for sleep power consumption. These very low sleep power results mean that energy consumed when monitors are off or in active use has become more important in terms of contribution to the overall unit energy consumption (UEC). Current ENERGY STAR monitor and computer criteria do not specify off or on power, but our results suggest opportunities for saving energy in these modes. Also, significant differences between CRT and LCD technology, and between field-measured and manufacturer-reported power levels reveal the need for standard methods and metrics for measuring and comparing monitor power consumption.%I Lawrence Berkeley National Laboratory %C Berkeley, CA %P 36 %8 07/2002 %G eng %2 LBNL-48581 %0 Report %D 2002 %T How Low Can You Go? Low Pressure Drop Laboratory Design %A John Weale %A Peter Rumsey %A Dale A. Sartor %A Eng Lock Lee %X
Laboratory buildings are characterized by the production of potentially hazardous fumes within the occupied space. The primary objective of a laboratory ventilation system is to isolate and protect the occupants from the fumes, as well as provide minimum outside air at a comfortable temperature. Fume removal results in the need for a large volume of conditioned make-up air, typically a significantly greater volume than required for space temperature conditioning purposes. The high quantity of exhaust naturally results in a once through system, which is also often required by codes that prohibit any recirculation in a laboratory space. The high costs associated with high airflow systems are magnified by the 24 hours a day, 356 days a year ventilation operation often seen in laboratory situations. All too often, the common design approach taken to laboratory mechanical systems results in a traditional office ventilation system upsized to meet a laboratorys requirements.
Recognizing the unique aspects of laboratory requirements and operation is essential to optimizing the mechanical system. Figure 1 shows a breakdown of a laboratory buildings electricity use, based on a DOE 2 model of a baseline laboratory building design for Montana State University (Bozeman, MT).
In laboratory buildings, the largest and easiest target for energy use reduction is usually the ventilation energy. At about 50% of the buildings total electricity usage, a 15% reduction in the power required by the ventilation system would save more energy than eliminating all lighting energy. As the largest component of a laboratorys energy consumption, the ventilation system is the first target to reduce the energy bill. Significantly improving the standard design efficiency of a ventilation system requires a lower air pressure drop system on both the supply and exhaust system.
Implementing low-pressure drop design strategies from the early stages of the design process will result in much lower energy costs throughout the systems life with a minimal increase in first costs. The pressure drop in a laboratory ventilation system is influenced by many independent design challenges. Knowing what these design challenges are and how they can be answered to minimize pressure drop is critical in achieving an energy efficient laboratory.%G eng %L LBNL-49366 %1
Applications Team%2 LBNL-49366 %0 Conference Paper %B 2002 ACEEE Summer Study on Energy Efficiency in Buildings %D 2002 %T Hurdling barriers through market uncertainty: Case studies in innovative technology adoption %A Christopher T. Payne %A Anthony Radspieler Jr. %A Jack Payne %X
The crisis atmosphere surrounding electricity availability in California during the summer of 2001 produced two distinct phenomena in commercial energy consumption decision-making: desires to guarantee energy availability while blackouts were still widely anticipated, and desires to avoid or mitigate significant price increases when higher commercial electricity tariffs took effect. The climate of increased consideration of these factors seems to have led, in some cases, to greater willingness on the part of business decision-makers to consider highly innovative technologies. This paper examines three case studies of innovative technology adoption: retrofit of time-and-temperature signs on an office building; installation of fuel cells to supply power, heating, and cooling to the same building; and installation of a gas-fired heat pump at a microbrewery. We examine the decision process that led to adoption of these technologies. In each case, specific constraints had made more conventional energy-efficient technologies inapplicable. We examine how these barriers to technology adoption developed over time, how the California energy decision-making climate combined with the characteristics of these innovative technologies to overcome the barriers, and what the implications of hurdling these barriers are for future energy decisions within the firms.%B 2002 ACEEE Summer Study on Energy Efficiency in Buildings %C Asilomar, CA %8 08/2002 %2 LBNL-50982 %0 Journal Article %J Physical Review B %D 2002 %T In Situ X-Ray Absorption Spectroscopy Study of Hydrogen Absorption by Nickel-Magnesium Thin Films %A Baker Farangis %A Ponnusamy Nachimuthu %A Thomas J. Richardson %A Jonathan L. Slack %A Rupert C.C. Perera %A Eric M. Gullikson %A Dennis W. Lindle %A Michael D. Rubin %X
Structural and electronic properties of co-sputtered Ni-Mg thin films with varying Ni to Mg ratio were studied by in situ x-ray absorption spectroscopy in the Ni L-edge and Mg K-edge regions. Codeposition of the metals led to increased disorder and decreased coordination around Ni and Mg compared to pure metal films. Exposure of the metallic films to hydrogen resulted in formation of hydrides and increased disorder. The presence of hydrogen as a near neighbor around Mg caused a drastic reduction in the intensities of multiple scattering resonances at higher energies. The optical switching behavior and changes in the x-ray spectra varied with Ni to Mg atomic ratio. Pure Mg films with Pd overlayers were converted to MgH2: The H atoms occupy regular sites as in bulk MgH2. Although optical switching was slow in the absence of Ni, the amount of H2 absorption was large. Incorporation of Ni in Mg films led to an increase in the speed of optical switching but decreased maximum transparency. Significant shifts in the Ni L3 and L2 peaks are consistent with strong interaction with hydrogen in the mixed films.%B Physical Review B %V 67 %8 02/2003 %G eng %N 8 %1
Windows and Daylighting Group%2 LBNL-51067 %! Phys. Rev. B %R 10.1103/PhysRevB.67.085106 %0 Journal Article %J ASHRAE Journal %D 2002 %T Laboratory Low-Pressure Drop Design %A John Weale %A Peter Rumsey %A Dale A. Sartor %A Eng Lock Lee %X
Laboratory buildings are characterized by the production of potentially hazardous fumes within the occupied space. The primary objective of a laboratory ventilation system is to isolate and protect the occupants from the fumes, as well as provide minimum outside air at a comfortable temperature. Fume removal results in the need for a large volume of conditioned make-up air, typically a significantly greater volume than required for space temperature conditioning purposes. The high quantity of exhaust naturally results in a once through system, which is also often required by codes that prohibit any recirculation in a laboratory space. The high costs associated with high airflow systems are magnified by the 24 hours a day, 356 days a year ventilation operation often seen in laboratory situations. All too often, the common design approach taken to laboratory mechanical systems results in a traditional office ventilation system upsized to meet a laboratory's requirements.%B ASHRAE Journal %V 44 %P 38-43 %8 08/2002 %G eng %N 8 %1
Applications Team%2 LBNL-49364 %& 38 %0 Conference Paper %B Solid State Ionics %D 2002 %T New Electrochromic Mirror Systems %A Thomas J. Richardson %X
Variable reflectance coatings (switchable mirrors) have significant advantages over traditional absorbing devices for radiant energy control in a variety of architectural and aerospace applications due to their large dynamic ranges in both transmission and reflection in the visible and near infrared regimes. Although electrochromic and gasochromic metal hydride films have been the primary focus of recent research in this field, other systems merit consideration. Two of these, based on electrochemical conversion of copper to copper oxides and of pnicogens to lithium pnictides are discussed here. Three distinct states are available in the copper system: the highly reflecting metal, the transparent Cu(I) oxide, and the black, highly absorbing Cu(II) oxide. Metallic thin films of elemental antimony and bismuth are reversibly converted to transparent, semiconducting lithium pnictides by cathodic polarization in a non-aqueous lithium electrolyte. Like the metal hydrides, these systems provide substantial modulation of near infrared transmission and reflection, but have somewhat lower visible reflectance in their mirror states.%B Solid State Ionics %C Golden, CO %V 165 %P 305-308 %8 08/2002 %G eng %L LBNL-51416 %1
Windows and Daylighting Group%2 LBNL-51416 %0 Report %D 2002 %T Optics Version 5.1.01 %A Richard Versluis %A Rebecca Powles %A Michael D. Rubin %I Regents of the University of California %C Berkeley, CA %8 11/2002 %G eng %L LBNL-52148 %1
Windows and Daylighting Group%2 LBNL-52148 %0 Conference Paper %B Fifth International Meeting on Electrochromism %D 2002 %T Structural and Electronic Properties of Magnesium-3D Transition Metal Switchable Mirrors %A Baker Farangis %A Ponnusamy Nachimuthu %A Thomas J. Richardson %A Jonathan L. Slack %A Bruno K. Meyer %A Rupert C.C. Perera %A Michael D. Rubin %K EXAFS %K Hydrogen storage materials %K NEXAFS %K thin films %K x-ray diffraction %X
We have observed reversible mirror-to-transparent state switching in a variety of mixed metal thin films containing magnesium and first-row transition elements including Ni, Fe, Co, Mn, and Ti. The very large changes in both reflectance and transmittance on loading these films with hydrogen are accompanied by significant structural and electronic transformations. The valence states and coordination of metal atoms during hydrogen loading were followed using dynamic in situ transmissionmode X-ray absorption spectroscopy. Time-resolved Mg K-edge and Ni, Co, Mn, and Ti L-edge spectra reflect both reversible and irreversible changes in the metal environments. These spectra are compared to those of reference materials and to predictions from calculations.%B Fifth International Meeting on Electrochromism %C Golden, CO %8 12/2002 %G eng %1
Windows and Daylighting Group%2 LBNL-51415 %R 10.1016/j.ssi.2003.08.041 %0 Journal Article %J Journal of Alloys and Compounds %D 2002 %T X-Ray Absorption Spectroscopy of Transition Metal-Magnesium Hydride Thin Films %A Thomas J. Richardson %A Baker Farangis %A Jonathan L. Slack %A Ponnusamy Nachimuthu %A Rupert C.C. Perera %A Nobumichi Tamura %A Michael D. Rubin %K EXAFS %K Hydrogen storage materials %K NEXAFS %K thin films %K x-ray diffraction %X
Mixed metal thin films containing magnesium and a first-row transition element exhibit very large changes in both reflectance and transmittance on exposure to hydrogen gas. Changes in electronic structure and coordination of the magnesium and transition metal atoms during hydrogen absorption were studied using dynamic in situ transmission mode X-ray absorption spectroscopy. Mg K-edge and Ni, Co, and Ti L-edge spectra reflect both reversible and irreversible changes in the metal environments. A significant shift in the nickel L absorption edge shows it to be an active participant in hydride formation. The effect on cobalt and titanium is much less dramatic, suggesting that these metals act primarily as catalysts for formation of magnesium hydride.%B Journal of Alloys and Compounds %V 356-357 %P 204-207 %8 08/2003 %G eng %1
Windows and Daylighting Group%2 LBNL-50574 %& 204 %R 10.1016/S0925-8388(02)01237-9 %0 Report %D 2001 %T Characterizing the fabric of the urban environment: a case study of metropolitan Chicago, Illinois %A Hashem Akbari %A Leanna S. Rose %K Case Studies %K Heat Island %X
Urban fabric data are needed in order to estimate the impact of light-colored surfaces (roofs and pavements) and urban vegetation (trees, grass, shrubs) on the meteorology and air quality of a city, and to design effective implementation programs. In this report, we discuss the result of a semi-automatic Monte-Carlo statistical approach used to develop data on surface-type distribution and city-fabric makeup (percentage of various surface-types) using aerial color orthophotography. The digital aerial photographs for metropolitan Chicago covered a total of about 36 km2 (14 mi2). At 0.3m resolution, there were approximately 3.9 x 108 pixels of data.
Four major land-use types were examined: commercial, industrial, residential, and transportation/communication. On average, for the areas studied, at ground level vegetation covers about 29% of the area (ranging 4-80%); roofs cover about 25% (ranging 8-41%), and paved surfaces about 33% (ranging 12-59%). For the most part, trees shade streets, parking lots, grass, and side-walks. In commercial areas, paved surfaces cover 50-60% of the area. In residential areas, on average, paved surfaces cover about 27% of the area.
Land-use/land-cover (LULC) data from the United States Geological Survey was used to extrapolate these results from neighborhood scales to metropolitan Chicago. In an area of roughly 2500 km2, defining most of metropolitan Chicago, over 53 percent is residential. The total roof area is about 680 km2, and the total paved surfaces (roads, parking areas, sidewalks) are about 880 km2. The total vegetated area is about 680 km2.%8 10/2001 %G eng %U http://repositories.cdlib.org/lbnl/LBNL-49275 %2 LBNL-49275 %0 Report %D 2001 %T Characterizing the fabric of the urban environment: a case study of Salt Lake City, Utah %A Hashem Akbari %A Leanna S. Rose %K Case Studies %K Heat Island %X
Urban fabric data are needed in order to estimate the impact of light-colored surfaces (roofs and pavements) and urban vegetation (trees, grass, shrubs) on the meteorology and air quality of a city, and to design effective implementation programs. In this report, we discuss the result of a semi-automatic Monte-Carlo statistical approach used to develop data on surface-type distribution and city-fabric makeup (percentage of various surface-types) using aerial color orthophotography. The digital aerial photographs for Salt Lake City covered a total of about 34 km2 (13 mi2). At 0.50-m resolution, there were approximately 1.4 x 108 pixels of data.
Four major land-use types were examined: 1) commercial, 2) industrial, 3) educational, and 4) residential. On average, for the areas studied, vegetation covers about 46% of the area (ranging 44-51%), roofs cover about 21% (ranging 15-24%), and paved surfaces about 26%(ranging 21-28%). For the most part, trees shade streets, parking lots, grass, and sidewalks. In most non-residential areas, paved surfaces cover 46-66% of the area. In residential areas, on average, paved surfaces cover about 32% of the area.
Land-use/land-cover (LU/LC) data from the United States Geological Survey were used to extrapolate these results from neighborhood scales to metropolitan Salt Lake City. In an area of roughly 560 km2, defining most of metropolitan Salt Lake City, over 60% is residential. The total roof area is about 110 km2, and the total paved surface area (roads, parking areas, sidewalks) covers about 170 km2. The total vegetated area covers about 230 km2.%8 02/2001 %G eng %U http://repositories.cdlib.org/lbnl/LBNL-47851 %2 LBNL-47851 %0 Conference Paper %B 2001 ACEEE Summer Study on Energy Efficiency in Industry %D 2001 %T Cleanroom Energy Benchmarking in High-Tech and Biotech Industries %A William F. Tschudi %A Kathleen Benschine %A Stephen Fok %A Peter Rumsey %X
Cleanrooms, critical to a wide range of industries, universities, and government facilities, are extremely energy intensive. Consequently, energy represents a significant operating cost for these facilities. Improving energy efficiency in cleanrooms will yield dramatic productivity improvement. But more importantly to the industries which rely on cleanrooms, base load reduction will also improve reliability. The number of cleanrooms in the US is growing and the cleanroom environmental systems energy use is increasing due to increases in total square footage and trends toward more energy intensive, higher cleanliness applications. In California, many industries important to the States economy utilize cleanrooms. In California these industries utilize over 150 cleanrooms with a total of 4.2 million sq. ft. (McIlvaine). Energy intensive high tech buildings offer an attractive incentive for large base load energy reduction. Opportunities for energy efficiency improvement exist in virtually all operating cleanrooms as well as in new designs.
To understand the opportunities and their potential impact, Pacific Gas and Electric Company sponsored a project to benchmark energy use in cleanrooms in the electronics (high-tech) and biotechnology industries. Both of these industries are heavily dependent intensive cleanroom environments for research and manufacturing. In California these two industries account for approximately 3.6 million sq. ft. of cleanroom (McIlvaine, 1996) and 4349 GWh/yr. (Sartor et al. 1999). Little comparative energy information on cleanroom environmental systems was previously available. Benchmarking energy use allows direct comparisons leading to identification of best practices, efficiency innovations, and highlighting previously masked design or operational problems.%B 2001 ACEEE Summer Study on Energy Efficiency in Industry %C Tarrytown, NY %8 07/2001 %G eng %L LBNL-47729 %1
Applications Team%2 LBNL-47729 %0 Book %D 2001 %T Daylight in Buildings. A Source Book on Daylighting Systems and Components %A Nancy Ruck %A Øyvind Aschehoug %A Sirri Aydinli %A Jens Christoffersen %A Gilles Courret %A Ian Edmonds %A Roman Jakobiak %A Martin Kischkoweit-Lopin %A Martin Klinger %A Eleanor S. Lee %A Laurent Michel %A Jean-Louis Scartezzini %A Stephen E. Selkowitz %G eng %U https://facades.lbl.gov/daylight-buildings-source-book-daylighting-systems %L LBNL-47493 %1
Windows and Daylighting Group%2 LBNL-47493 %0 Conference Paper %B 2001 IESNA National Conference %D 2001 %T Daylighting, Dimming, and the Electricity Crisis in California %A Francis M. Rubinstein %A Danielle Neils %A Nesrin Colak %X
Dimming controls for electric lighting have been one of the mainstays of the effort to use daylighting to reduce annual lighting energy consumption. The coincidence of daylighting with electric utility peak demand makes daylighting controls an effective strategy for reducing commercial building peak electric loads. During times of energy shortage, there is a greatly increased need to reduce electricity use during peak periods, both to ease the burden on electricity providers and to control the operating costs of buildings. The paper presents a typical commercial building electric demand profile during summer, and shows how daylighting-linked lighting controls and load shedding techniques can reduce lighting at precisely those times when electricity is most expensive. We look at the importance of dimming for increasing the reliability of the electricity grid in California and other states, as well as examine the potential cost-effectiveness of widespread use of daylighting to save energy and reduce monthly electricity bills.%B 2001 IESNA National Conference %C Ottawa, Canada %8 08/2001 %G eng %L LBNL-49971 %1
Lighting Systems Group%2 LBNL-49971 %0 Conference Paper %B 2001 Conference of the Illuminating Engineering Society of North America (IES) %D 2001 %T Effect of Occupancy Sensors on Energy Usage and Peak Demand in Commercial Office Buildings: Part 1 %A David M. Keith %A Francis M. Rubinstein %B 2001 Conference of the Illuminating Engineering Society of North America (IES) %C Ottawa, Canada %8 08/2001 %G eng %L LBNL-48397 %1
Lighting Systems Group%2 LBNL-48397 %0 Journal Article %D 2001 %T Field Surveys of Office Equipment Operating Patterns %A Carrie A. Webber %A Judy A. Roberson %A Richard E. Brown %A Christopher T. Payne %A Bruce Nordman %A Jonathan G. Koomey %K Enduse %K Energy End-Use Forecasting %K EUF %X
This paper presents the results of 11 after-hours walk-throughs of offices in the San Francisco CA and Washington D.C. areas. The primary purpose of these walk-throughs was to collect data on turn-off rates for various types of office equipment (computers, monitors, printers, fax machines, copiers, and multifunction products). Each piece of equipment observed was recorded and its power status noted (e.g. on, off, low power). Whenever possible, we also recorded whether power management was enabled on the equipment. The floor area audited was recorded as well, which allowed us to calculate equipment densities. We found that only 44 percent of computers, 32 percent of monitors, and 25 percent of printers were turned off at night. Based on our observations we estimate success rates of 56 percent for monitor power management and 96 percent for enabling of power management on printers.%I Lawrence Berkeley National Laboratory %C Berkeley, CA %8 09/2001 %@ LBNL-46930 %G eng %2 LBNL-46930 %0 Report %D 2001 %T Final Report on Internet Addressable Light Switch %A Francis M. Rubinstein %A Pete Pettler %X
This report describes the work performed to develop and test a new switching system and communications network that is useful for economically switching lighting circuits in existing commercial buildings. The first section of the report provides the general background of the IBECS (Integrated Building Environmental Communications System) research and development work as well as the context for the development of the new switching system. The research and development effort that went into producing the first proof-of-concept (the IBECS Addressable Power Switch or APS) and the physical prototype of that concept is detailed in the second section. In the third section of the report, we detail the refined Powerline Carrier Based IBECS Title 24 Wall Switch system that evolved from the APS prototype. The refined system provided a path for installing IBECS switching technology in existing buildings that may not be already wired for light level switching control. The final section of the report describes the performance of the IBECS Title 24 Switch system as applied to a small demonstration in two offices at LBNLs Building 90. We learned that the new Powerline Carrier control systems (A-10 technology) that have evolved from the early X-10 systems have solved most of the noise problems that dogged the successful application of X-10 technologies in commercial buildings. We found that the new A-10 powerline carrier control technology can be reliable and effective for switching lighting circuits even in electrically noisy office environments like LBNL. Thus we successfully completed the task objectives by designing, building and demonstrating a new switching system that can provide multiple levels of light which can be triggered either from specially designed wall switches or from a digital communications network. By applying commercially available powerline carrier based technologies that communicate over the in-place lighting wiring system, this type of control can be economically installed even in existing buildings that were not wired for dual-level lighting.%G eng %L LBNL-49974 %1
Lighting Systems Group%2 LBNL-49974 %0 Report %D 2001 %T IBECS Network/Ballast Interface - Final Report %A Francis M. Rubinstein %A Pete Pettler %X
This report describes the work performed to design, develop, and demonstrate an IBECS network/ballast interface that is useful for economically dimming controllable ballasts in commercial buildings. The first section of the report provides the general background of the IBECS (Integrated Building Environmental Communications System) research and development work as well as the context for the development of the network/ballast interface. The research and development effort that went into producing the first proof-of-concept circuit and the physical prototype of that concept is detailed in the second section. In the third section of the report, we describe the lessons learned from the first demonstration of the network/ballast interface at an office at LBNL. The fourth section describes how electrical noise interference encountered with the first generation of interface led to design changes for a refined prototype that hardened the interface from electrical noise generated by the ballast. The final section of the report discusses the performance of refined prototype after we replaced the proof-of-concept prototype with the refined prototypes in the demonstration office at LBNL.%G eng %L LBNL-49973 %1
Lighting Systems Group%2 LBNL-49973 %0 Report %D 2001 %T Losing Weight to Save Lives: A Review of the Role of Automobile Weight and Size in Traffic Fatalities %A Thomas P. Wenzel %A Marc Ross %8 07/2001 %G eng %2 LBNL-48009 %0 Journal Article %J Energy and Buildings %D 2001 %T A Method for Simulating the Performance of Photosensor-Based Lighting Controls %A Charles K. Ehrlich %A Konstantinos M. Papamichael %A Judy Lai %A Kenneth L. Revzan %X
The unreliability of photosensor-based lighting controls continues to be a significant market barrier that prevents widespread acceptance of daylight dimming controls in commercial buildings. Energy savings from the use of daylighting in commercial buildings is best realized through the installation of reliable photoelectric lighting controls that dim electric lights when sufficient daylight is available to provide adequate background and/or task illumination. In prior work, the authors discussed the limitations of current simulation approaches and presented a robust method to simulate the performance of photosensor-based controls using an enhanced version of the radiance lighting simulation package. The method is based on the concept of multiplying two fisheye images: one generated from the angular sensitivity of the photosensor and the other from a 180 or 360 deg. fisheye image of the space as seen by the photosensor. This paper includes a description of the method, its validation and possible applications for designing, placing, calibrating and commissioning photosensor-based lighting controls.%B Energy and Buildings %V 34 %P 883-889 %G eng %L LBNL-49018 %1
Windows and Daylighting Group%2 LBNL-49018 %0 Journal Article %J Applied Physics Letters %D 2001 %T Mixed Metal Films with Switchable Optical Properties %A Thomas J. Richardson %A Jonathan L. Slack %A Baker Farangis %A Michael D. Rubin %X
Thin, Pd-capped metallic films containing magnesium and first row transition metals (Mn, Fe, Co) switch reversibly from their initial reflecting state to visually transparent states when exposed to gaseous hydrogen or following reduction cathodic polarization in an alkaline electrolyte. Reversion to the reflecting state is achieved by exposure to air or by anodic polarization. The films were prepared by co-sputtering from one magnesium target and one manganese, iron, or cobalt target. Both the dynamic optical switching range and the speed of the transition depend on the magnesium-transition metal ratio. Infrared spectra of films in the transparent, hydrided (deuterided) states support the presence of the intermetallic hydride phases Mg3MnH7, Mg2FeH6, and Mg2CoH5.%B Applied Physics Letters %V 80 %P 1349-1351 %8 02/2002 %G eng %N 8 %1
Windows and Daylighting Group%2 LBNL-49043 %R 10.1063/1.1454218 %0 Journal Article %J Building and Environment %D 2001 %T A Nodal Model for Displacement Ventilation and Chilled Ceiling Systems in Office Spaces %A Simon J. Rees %A Philip Haves %K Chilled ceilings %K commercial buildings %K Displacement ventilation %K energy %K Heat Transfer %K Nodal model %K simulation %X
A nodal model has been developed to represent room heat transfer in displacement ventilation and chilled ceiling systems. The model uses precalculated air flow rates to predict the air temperature distribution and the division of the cooling load between the ventilation air and the chilled ceiling. The air movements in the plumes and the rest of the room are represented separately using a network of ten air nodes. The values of the capacity rate parameters are calculated by solving the heat and mass balance equations for each node using measured temperatures as inputs. Correlations between parameter values for a range of cooling loads and supply air flow rates are presented.%B Building and Environment %V 36 %P 753-762 %8 07/2001 %G eng %U http://www.ibpsa.org/proceedings/BS1999/BS99_D-05.pdf %N 6 %& 753 %R 10.1016/S0360-1323(00)00067-6 %0 Journal Article %J International Journal of Heat and Mass Transfer %D 2001 %T Numerical Investigation of Transient Buoyant Flow in a Room with a Displacement Ventilation and Chilled Ceiling System %A Simon J. Rees %A James J. McGuirk %A Philip Haves %X
The air flow in the office ventilation system known as displacement ventilation is dominated by a gravity current from the inlet and buoyant plumes above internal heat sources. Calculations of the flow and heat transfer in a typical office room have been made for this type of ventilation system used in conjunction with chilled ceiling panels. These calculations have been made in parallel with full size test chamber experiments. It has been found that with higher values of internal load (45 and 72 W m−2 of floor area) the flow becomes quasi-periodic in nature. Complex lateral oscillations are seen in the plumes above the heat sources which impinge on the ceiling and induce significant recirculating flows in the room. The frequency spectra of the transient calculations show good agreement with those of the experimental results. Comparison is also made between calculated mean room air speeds and temperature profiles and measured values.%B International Journal of Heat and Mass Transfer %V 44 %P 3067-3080 %8 08/2001 %G eng %U http://www.sciencedirect.com/science/article/pii/S0017931000003483 %N 16 %& 3067 %R 10.1016/S0017-9310(00)00348-3 %0 Journal Article %J Journal of the Illuminating Engineering Society %D 2001 %T Occupancy and Time-Based Lighting Controls in Open Offices %A Judy D. Jennings %A Nesrin Colak %A Francis M. Rubinstein %X
We present analyses of two years lighting data in open office areas, controlled by occupant sensors, time scheduling, or wall switches alone. We compare the energy savings using a before-after analysis of time scheduling and a conservative moving baseline analysis of both occupant sensing and time scheduling. We found that both techniques saved energy effectively when no occupants were present compared with wall switches alone. Time scheduling saved from 0.7 to 6.6% or an average of about 5%. Occupant sensors in similar areas saved from 9.0 to 14.6%, with an average of about 10%. False triggering of occupant sensors (by passersby) that would have caused energy waste was avoided by the presence of wall switches that positively turned lights off. Variations in occupant schedules and habits affected overall lighting energy use and the appropriateness of different control types. Little savings were found during the normal 8am to 5pm workday from either technology in large offices, but significant savings occurred after hours and on weekends. Our findings contrast with previous results for private offices in which only a single occupant is present, strengthening the evidence that different types of office space can be controlled appropriately with different types of control systems. However, small percentage savings in open areas result in larger actual savings due to the large number of fixtures controlled.%B Journal of the Illuminating Engineering Society %V 31 %P 86-100 %G eng %L LBNL-47022 %1
Lighting Systems Group%2 LBNL-47022 %0 Report %D 2001 %T A Sensitivity Analysis of the Treatment of Wind Energy in the AEO99 Version of NEMS %A Julie G. Osborn %A Frances Wood %A R. Cooper Richey %A Sandy Sanders %A Walter Short %A Jonathan G. Koomey %K AEO99 %K electricity markets and policy group %K Enduse %K energy analysis and environmental impacts department %K Energy End-Use Forecasting %K EUF %K nems %K wind energy %X
This study investigates the effect of modeling assumptions about levelized costs and market penetration on the U.S. Department of Energy's Annual Energy Outlook (AEO) forecast for wind technologies. The AEO's annual report of energy supply, demand, and prices through 2020 is based on results from the Energy Information Administration (EIA) National Energy Modeling System (NEMS). NEMS predicts the market penetration of individual energy technologies based on a variety of inputs and assumed changes in these base values over time. The NEMS forecast of technology adoption and use is influenced most strongly by the model's assumptions about the levelized cost of energy for the various technologies. For each year, NEMS allocates a share of the energy market to least-cost technologies; this allocation affects forecasts for future years. NEMS uses cost multipliers and constraints to represent potential physical and economic limitations on growth in capacity; these limitations include depletion of resources, costs of rapid manufacturing expansion, and the stability or instability of the power grid when high levels of generation come from intermittent resources. Wind power was chosen as a case study because it is found over a relatively wide geographic range and is the closest of the renewable technologies to being economically competitive. Because wind power is modeled similarly to some of the other renewable technologies, such as solar thermal and photovoltaics (PV), our findings may be applicable to these areas of NEMS as well. Our sensitivity analysis focused on relaxing assumptions (not including capital cost) to make them less restrictive to wind development. In our initial explorations, we conducted a limited set of runs with more restrictive assumptions and found that those scenarios did not differ much from the Reference Case results. Therefore, we concluded that further restricting the assumptions would not be very instructive. In this report, we first review the NEMS model structure and input data for wind power. We then present the results of a sensitivity analysis of wind development in NEMS to the assumptions other than capital cost that are used by the model for economic and physical conditions that affect wind resource development.%I LBNL %C Berkeley %P 43 %8 01/2001 %2 LBNL-44070 %0 Conference Paper %B 2001 Building Simulation 7th International Building Performance Simulation Association Conference %D 2001 %T Simulating the Operation of Photosensor-Based Lighting Controls %A Charles K. Ehrlich %A Konstantinos M. Papamichael %A Judy Lai %A Kenneth L. Revzan %X
Energy savings from the use of daylighting in commercial buildings are realized through implementation of photoelectric lighting controls that dim electric lights when sufficient daylight is available to provide adequate workplane illumination. The dimming level of electric lighting is based on the signal of a photosensor. Current simulation approaches for such systems are based on the questionable assumption that the signal of the photosensor is proportional to the task illuminance. This paper presents a method that simulates the performance of photosensor controls considering the acceptance angle, angular sensitivity, placement of the photosensor within a space, and color correction filter. The method is based on the multiplication of two fisheye images: one generated from the angular sensitivity of the photosensor and the other from a 180- or 360-degree fisheye image of the space as seen by the photosensor. The paper includes a detailed description of the method and its implementation, example applications, and validation results based on comparison with measurements in an actual office space.%B 2001 Building Simulation 7th International Building Performance Simulation Association Conference %C Rio de Janeiro, Brazil %8 08/2001 %G eng %L LBNL-47544 %1
Windows and Daylighting Group%2 LBNL-47544 %0 Journal Article %J Applied Physics Letters %D 2001 %T Switchable Mirrors Based on Nickel-Magnesium Films %A Thomas J. Richardson %A Jonathan L. Slack %A Robert D. Armitage %A Robert Kostecki %A Baker Farangis %A Michael D. Rubin %X
An electrochromic mirror electrode based on reversible uptake of hydrogen in nickel magnesium alloy films is reported. Thin, magnesium-rich Ni-Mg films prepared on glass substrates by cosputtering from Ni and Mg targets are mirror-like in appearance and have low visible transmittance. Upon exposure to hydrogen gas or on cathodic polarization in alkaline electrolyte, the films take up hydrogen and become transparent. When hydrogen is removed, the mirror properties are recovered. The transition is believed to result from reversible formation of Mg2NiH4 and MgH2. A thin overlayer of palladium was found to enhance the kinetics of hydrogen insertion and extraction, and to protect the metal surface against oxidation.%B Applied Physics Letters %V 78 %P 3047-3049 %8 05/2001 %G eng %N 20 %1
Windows and Daylighting Group%2 LBNL-47180 %& 3047 %R 10.1063/1.1371959 %0 Journal Article %J Journal of the Illuminating Engineering Society %D 2000 %T Comparison of Control Options in Private Offices in an Advanced Lighting Controls Testbed %A Judy D. Jennings %A Francis M. Rubinstein %A Dennis L. DiBartolomeo %A Steven L. Blanc %X
In a major test of different lighting control technologies in a typical office building, we present analyses of seven months results from five control scenarios in private offices. We compare the energy savings and effectiveness of various combinations of occupant detection, daylight dimming, and switching techniques. Comparing measured energy use with occupant sensors against baseline energy use calculated using wall switch operation only, we found that occupant sensors saved 20-26% lighting energy compared to manual switching alone. In offices where light sensor controls were installed and properly commissioned, additional savings up to 27% for a total of 46% were obtained over a seven-month period, even in an area with unusually high minimum lighting requirements. Dimming the lighting system to desired task levels (task tuning) also resulted in significant (23% additional, 43% total) energy savings in overlit areas. On the base case floor, where only bi-level switches were installed, we found significant usage of only one switch resulting in an additional 23% savings over single-level switches-an unexpected result withimplications for building code requirements. We found that the energy savings due to occupant sensing vs. dimming depended on the behavior of occupants. In offices whose occupants tended to stay at their desks all day, dimming controls saved more energy, and vice versa. The lighting requirements of occupants appear to depend on their type of work.%B Journal of the Illuminating Engineering Society %G eng %L LBNL-43096 Rev. %1
Lighting Systems Group%2 LBNL-43096R %0 Journal Article %J Building Services Engineering Research & Technology %D 2000 %T Comparison of Peak Load Predictions and Treatment of Solar Gains in the Admittance and Heat Balance Load Calculation Procedures %A Simon J. Rees %A Jeffrey D. Spitler %A Michael J. Holmes %A Philip Haves %X Calculation of design cooling loads is of critical concern to designers of HVAC systems. The work reported here has been carried out under a joint ASHRAE-CIBSE research project to compare design cooling calculation methods. Peak cooling loads predicted by the ASHRAE heat balance method are compared with those predicted by a number of implementations of the admittance method using different window models. The results presented show the general trends in overprediction or underprediction of peak load. Particular attention is given to different window modelling practices. The performance of the methods is explained in terms of some of the underlying assumptions in the window models, and by reference to specific inter-model comparisons. %B Building Services Engineering Research & Technology %V 21 %G eng %U http://bse.sagepub.com/content/21/2/125 %N 2 %R 10.1177/014362440002100207 %0 Journal Article %J Macmillan Encyclopedia of Energy %D 2000 %T Cool communities %A Hashem Akbari %A Arthur H. Rosenfeld %K Heat Island %K urban heat island %X
As modern urban areas have grown, there has been a corresponding growth in darker surfaces and a decline in vegetation, affecting urban climate, energy use, and habitability. Dark roofs heat up more and thus raise the summertime cooling demands of buildings, collectively with reduced vegetation, warming the air over urban areas and creating "heat islands." On a clear summer afternoon, the air temperature in a typical city can be as much as 2.5ºC (4.5ºF) higher than in surrounding rural areas. (The peak heat island effect occurs during cold winter evenings and is caused primarily by the rapid cooling of the rural areas - the thermal storage of pavements and dark-roofed buildings is much greater than greenery.) Peak urban electric demand rises by 2 to 4 percent for each 1ºC (1.8ºF) rise in daily maximum temperature above 15 to 20ºC (59 to 68ºF), so the additional airconditioning
use caused by higher urban air temperature is responsible for 5 to 10 percent of urban peak electric demand, costing U.S. ratepayers several billion dollars annually. Temperatures in cities are increasing. Figure I depicts summertime monthly maximum
and minimum temperatures between 1877 and 1997 in downtown Los Angeles, clearly indicating that these maximum temperatures are now about 2.5ºC (4.5ºF) higher than in 1920. Minimum temperatures are about 4ºC (7.2ºF) higher than in 1880. In California from 1965 to 1989, the average urban-rural temperature differences, measured at thirtyone pairs of urban and rural stations, have increased by about 1ºC (1.8ºF). In Washington, D.C., temperatures rose 2ºC (3.6ºF) between 1871 and 1987. This recent warming trend is typical of most U.S. metropolitan areas and exacerbates demand for energy. In Los Angeles, we estimate a heat-island induced increase in power consumption of 1 to 1.5 GW, costing ratepayers $100 million per year. Besides increasing systemwide cooling loads, summer heat islands increase smog production. Smog production is a highly temperature-sensitive process. At maximum daily temperatures below 22ºC (71.6ºF), maximum ozone concentration in Los Angeles is below the California standard of 90 parts per billion. At 35ºC (95ºF), practically all days in Los Angeles are smoggy (see Figure 2).%B Macmillan Encyclopedia of Energy %V 1 %P 305-8 %G eng %2 LBL-44129 %0 Conference Paper %B 4th International Meeting on Electrochromism %D 2000 %T Electrochromism in Copper Oxide Thin Films %A Thomas J. Richardson %A Jonathan L. Slack %A Michael D. Rubin %X
Transparent thin films of copper(I) oxide prepared on conductive SnO2:F glass substrates by anodic oxidation of sputtered copper films or by direct electrodeposition of Cu2O transformed reversibly to opaque metallic copper films when reduced in alkaline electrolyte. In addition, the same Cu2O films transform reversibly to black copper(II) oxide when cycled at more anodic potentials. Copper oxide-to-copper switching covered a large dynamic range, from 85% and 10% photopic transmittance, with a coloration efficiency of about 32 cm2/C. Gradual deterioration of the switching range occurred over 20 to 100 cycles. This is tentatively ascribed to coarsening of the film and contact degradation caused by the 65% volume change on conversion of Cu to Cu2O. Switching between the two copper oxides (which have similar volumes) was more stable and more efficient (CE = 60 cm2/C), but covered a smaller transmittance range (60% to 44% T). Due to their large electrochemical storage capacity and tolerance for alkaline electrolytes, these cathodically coloring films may be useful as counter electrodes for anodically coloring electrode films such as nickel oxide or metal hydrides.%B 4th International Meeting on Electrochromism %C Uppsala, Sweden %8 08/2000 %G eng %L LBNL-46510 %1
Windows and Daylighting Group%2 LBNL-46510 %0 Conference Paper %B 2000 ACEEE Summer Study on Energy Efficiency in Buildings %D 2000 %T IBECS: An Integrated Building Environmental Communications System--Its Not Your Fathers Network %A Francis M. Rubinstein %A Stephen G. Johnson %X
The paper presents the technical design concept for a low-cost building communications network that will allow most building equipment loads, including individual light fixtures, operable window blinds, motors and environmental sensors, to be controlled and monitored from an existing Ethernet. IBECS (Integrated Building Environmental Communications System) is a practical networking system that will provide building managers with an unprecedented degree of control over most building electrical loads, allowing them to implement load shedding, real time pricing and aggregated building load strategies with confidence. At the same time, IBECS will let individual occupants exert appropriate control over their environmental conditions (light and, ultimately, heat), initially using a virtual control panel served from their web browser, and eventually through voice command. Recent developments in hardware and software have enabled this new networking concept. New manufacturing techniques can produce semiconductor devices that incorporate a microprocessor, unique IP address, controller, and simple LAN communications for $0.25/chip. The private sector is already hugely invested in software that makes appliances, peripherals and telecommunications devices addressable via the Internet (e.g., Sun Microsystems Jini technology - a software infrastructure for providing services on a network). Because it directly exploits recent developments in hardware and software that are far beyond the development capabilities of the building industry, IBECS could provide the infrastructure that, for the first time, truly integrates the operation of building equipment to improve both human and building performance.%B 2000 ACEEE Summer Study on Energy Efficiency in Buildings %C Pacific Grove, CA %8 08/2000 %G eng %L LBNL-46009 %1
Lighting Systems Group%2 LBNL-46009 %0 Conference Paper %B Electrochimica Acta %D 2000 %T Liquid Phase Deposition of Electrochromic Thin Films %A Thomas J. Richardson %A Michael D. Rubin %X
Thin films of titanium, zirconium and nickel oxides were deposited on conductive SnO2:F glass substrates by immersion in aqueous solutions. The films are transparent, conformal, of uniform thickness and appearance, and adhere strongly to the substrates. On electrochemical cycling, TiO2, mixed TiO2-ZrO2, and NiOx films exhibited stable electrochromism with high coloration efficiencies. These nickel oxide films were particularly stable compared with films prepared by other non-vacuum techniques. The method is simple, inexpensive, energy efficient, and readily scalable to larger substrates.%B Electrochimica Acta %C Uppsala, Sweden %V 46 %P 2119-2123 %8 08/2000 %G eng %L LBNL-46612 %1
Windows and Daylighting Group%2 LBNL-46612 %0 Report %D 2000 %T Measured energy savings from the application of reflective roofs in 3 AT&T regeneration buildings %A Hashem Akbari %A Leo I. Rainer %K Case Studies %K Heat Island %X
Energy use and environmental parameters were monitored in three AT&T regeneration buildings during the summer of 2000. These buildings are constructed with concrete and are about 14.9 m2 (160 f2; 10x16 ft) in size. The buildings were initially monitored for about 1 1/2 months to establish a base condition. Then, the roofs of the buildings were painted with a white coating and the monitoring was continued. The original roof reflectances were about 26 percent; after the application of roof coatings the reflectivities increased to about 72 percent.
In two of these buildings, we monitored savings of about 0.5kWh per day (8.6 kWh/m2 [0.8 kWh/ft2]). The third building showed a reduction in air-conditioning energy use of about 13kWh per day. These savings probably resulted from the differences in the performance (EER) of the two dissimilar AC units in this building.
The estimated annual savings for two of the buildings are about 125kWh per year; at a cost of $0.1/kWh, savings are about $12.5 per year. Obviously, it costs significantly more than this amount to coat the roofs with reflective coating, particularly because of the remote location of the buildings. However, since the prefabricated roofs are already painted green at the factory, painting them with white (reflective) color would bring no additional cost. Hence the payback time for having reflective roofs is nil, and the reflective roofs save an accumulated 370kWh over 30 years of the life of the roof.%I Lawrence Berkeley National Laboratory %C Berkeley %8 11/2000 %G eng %2 LBNL-47075 %0 Report %D 2000 %T National Energy Use of Consumer Electronics in 1999 %A Karen Rosen %A Alan K. Meier %A Stefan Zandelin %X
The major consumer electronics in U.S. homes accounted for nearly 7% of U.S. residential electricity consumption in 1999. We attribute more than half of this figure (3.6%) to televisions, videocassette recorders, and DVD players, and nearly one-third (1.8%) to audio products. Set-top boxes currently account for a relatively small fraction of residential electricity use (0.7%), but we expect this end-use to grow quickly with the proliferation of digital set-top boxes, which currently use 40% more energy per unit than the average TV set. In all, these consumer electronics plus telephony products consumed 75 TWh in the U.S. in 1999, half of which was consumed while the products were not in use. This energy use is expected to grow as products with new or advanced functionality hit the market.%8 06/2000 %2 LBNL-45988 %0 Conference Paper %B Revista della Statzione Sperimentale del Vetro %D 2000 %T Optical Properties of Glazing Materials at Normal Incidence %A Michael D. Rubin %A Rebecca Powles %X
Measurements of spectral transmittance T and reflectance R at normal incidence continue to be the most common and accurate source of energy performance data for glazing materials. Prediction of these radiometric properties from more fundamental materials data is often confounded by the complexity and uncertainty of coating structures. Angle-dependent radiometric properties of coated glazing will probably be predicted from normal-incidence data rather than being measured at many angles. The general error level demonstrated in round-robin tests is on the order 1-2%; it is often necessary to achieve better levels of performance. Based on results obtained following the round-robin tests, it is expected that accuracy of better than 0.5% can be generally achieved. A new type of absolute standard reference is described and tested with promising results.%B Revista della Statzione Sperimentale del Vetro %C Paris, France %P 13-16 %8 10/2000 %G eng %L LBNL-48322 %1
Windows and Daylighting Group%2 LBNL-48322 %0 Journal Article %J International Journal of Heating, Ventilating, Air-Conditioning and Refrigeration Research %D 2000 %T Qualitative Comparison of North American and U.K. Cooling Load Calculation Procedures %A Simon J. Rees %A Jeffrey D. Spitler %A Morris G. Davies %A Philip Haves %X
A qualitative comparison is presented between three current North American and U.K. design cooling load calculation methods. The methods compared are the ASHRAE Heat Balance Method, the Radiant Time Series Method and the Admittance Method, used in the U.K. The methods are compared and contrasted in terms of their overall structure. In order to generate the values of the 24 hourly cooling loads, comparison was also made in terms of the processing of the input data and the solution of the equations required. Specific comparisons are made between the approximations used by the three calculation methods to model some of the principal heat transfer mechanisms. Conclusions are drawn regarding the ability of the simplified methods to correctly predict peak-cooling loads compared to the Heat Balance Method predictions. Comment is also made on the potential for developing similar approaches to cooling load calculation in the U.K. and North America in the future.%B International Journal of Heating, Ventilating, Air-Conditioning and Refrigeration Research %V 6 %P 75-99 %G eng %N 1 %& 75 %R 10.1080/10789669.2000.10391251 %0 Conference Proceedings %B Healthy Buildings 2000 %D 2000 %T Research Needs and Approaches Pertaining to the Indoor Climate and Productivity %A David P. Wyon %A William J. Fisk %A Sari Rautio %E Olli Seppänen %E Marianna Tuomainen %E Jorma Säteri %X
The indoor environment affects the health, comfort and performance of occupants. All three are important, but the cost of improved design, operation, maintenance and energy use in buildings must usually be justified in terms of the expected effects on productivity. While there is no doubt that effects on health, comfort and performance translate into effects on productivity, there is an urgent need to discover which of the hypothesised mechanisms of cause and effect are valid to quantify how much each mechanism affects productivity in different work situations, and to validate predictions in the field.%B Healthy Buildings 2000 %I SIY Indoor Air Information %C Helsinki, Finland %V 2 %P 327-332 %G eng %1
1.2%2 LBNL-48219 %& Chapter %0 Report %D 2000 %T Whole-House Measurements of Standby Power Consumption %A J.P. Ross %A Alan K. Meier %X
We investigated the variation in standby power consumption in ten California homes. Total standby power in the homes ranged from 14–169 W, with an average of 67 W. This corresponded to 5%–26% of the homes' annual electricity use. The appliances with the largest standby losses were televisions, set-top boxes and printers. The large variation in the standby power of appliances providing the same service demonstrates that manufacturers are able to reduce standby losses without degrading performance. Replacing existing units with appliances with 1 W or less of standby power would reduce standby losses by 68%.%8 06/2000 %G eng %2 LBNL-45967 %0 Report %D 1999 %T Characterizing the fabric of the urban environment: a case study of Sacramento, California %A Hashem Akbari %A Leanna S. Rose %A Haider Taha %K Case Studies %K Heat Island %X
To estimate the impact of light-colored surfaces (roofs and pavements) and urban vegetation (trees, grass, shrubs) on meteorology and air quality of a city, it is essential to accurately estimate the fraction of various urban surfaces. In this report, we estimate the fabric of Sacramento by analyzing high-resolution (0.30-m) aerial color photographs of about 65 square km of the urban area. The analysis show that in downtown Sacramento, vegetation as seen from above the canopy covers 30% of the area, whereas roofs cover 23% and paved surface 41%. Under-the-canopy fabric consists of 52% paved surfaces, 26% roofs, and 12% grass. In the industrial areas, vegetation covers 8-14% of the area, roofs cover 19-23%, and paved surfaces cover 29-44%. The surface-type percentages in the office areas are 21% trees, 16% roofs, and 49% paved surfaces. In commercial areas,vegetation covers 5-20%, roofs 19-20%, paved surfaces 44-68%. Residential areas exhibit a wide range of percentages of surface-types . On average, vegetation covers about 36% of the area, roofs cover about 20%, and paved surfaces about 28%. Trees mostly shade streets, parking lots, grass, and sidewalks. Under the canopy the percentage of paved surfaces is significantly higher. In most non-residential areas, paved surfaces cover 50-70% of the area. In residential areas, on average, paved surfaces cover about 35% of the area. For an area of roughly 800 sq. km, defining most of metropolitan Sacramento, about half is residential. The total roof area is about 150 sq. km and the total paved surfaces (roads, parking areas, sidewalks) is about 310 sq. km. The total vegetated area is about 230 sq. km.%G eng %R 10.2172/764362 %0 Conference Proceedings %B Proceedings of the Indoor Air 99, Edinburgh, Scotland %D 1999 %T Effect of Reversible, Diffusion-Controlled Sinks on VOC Concentrations in Buildings %A Dongye Y Zhao %A Julien Rouques %A John C. Little %A Alfred T. Hodgson %B Proceedings of the Indoor Air 99, Edinburgh, Scotland %I Construction Research Communications, Ltd., London %V 5 %P 264-269 %G eng %1 2.6 %2 LBNL-43848 %& Chapter %0 Journal Article %J IEEE Transactions on Plasma Science %D 1999 %T Evaluation of the Plasma Distribution of a Quasi-Linear Constricted Plasma Source %A André Anders %A Robert A. MacGill %A Michael D. Rubin %K Constricted plasma source %K gas plasma flow %K plasma diagnostics %K plasma processing of materials %X
The quasi-linear constricted plasma source is a downstream plasma source with ten linearly aligned discharge cells. Each cell operates on the basis of a constricted glow discharge. The plasma output can easily be monitored by the plasma-emitted light. The information is not only intuitive but can also be used to operate on-line feedback control of the plasma source which is important for large-area plasma processing of materials.%B IEEE Transactions on Plasma Science %V 27 %P 82-83 %8 02/1999 %G eng %N 1 %1
Windows and Daylighting Group%2 LBNL-42016 %& 82 %0 Report %D 1999 %T Lighting Recommendations for the Social Security Administration Frank Hagel Federal Building in Richmond CA %A Francis M. Rubinstein %X
Specific recommendations are made to improve the lighting quality and energy efficiency of the lighting system at the Social Security Administration Frank Hagel Building in Richmond, CA. The main recommendation is to replace the recessed fluorescent lighting system in the general office area with indirect lighting. Indirect lighting will improve lighting quality, will provide an energy efficient solution and will be about the same cost as the direct lighting system originally proposed.%G eng %L LBNL-46101 %1
Lighting Systems Group%2 LBNL-46101 %0 Conference Proceedings %B Building Simulation '99 %D 1999 %T A Nodal Model for Displacement Ventilation and Chilled Ceiling Systems in Office Spaces %A Simon J. Rees %A Philip Haves %X
A nodal model has been developed to represent room heat transfer in displacement ventilation and chilled ceiling systems. The model uses precalculated air flow rates to predict the air temperature distribution and the division of the cooling load between the ventilation air and the chilled ceiling. The air movements in the plumes and the rest of the room are rep- resented separately using a network of ten air nodes. The values of the capacity rate parameters are calculated by solving the heat and mass balance equations for each node using measured temperatures as inputs. Correlations between parameter values for a range of cooling loads and supply air flow rates are presented.%B Building Simulation '99 %C Kyoto, Japan %8 09/1999 %G eng %U http://www.ibpsa.org/proceedings/BS1999/BS99_D-05.pdf %0 Report %D 1999 %T Performance Assessment and Adoption Processes of an Information Monitoring and Diagnostic System Prototype %A Mary Ann Piette %A Satkartar Kinney %A Philip Haves %A Peter Rumsey %A Kristopher L. Kinney %A Eng Lock Lee %A Anthony Sebald %A Kumar Chellapilla %A Christine Shockman %X
This report addresses the problem that buildings do not perform as well as anticipated during design. We partnered with an innovative building operator to evaluate a prototype Information Monitoring and Diagnostic System (IMDS). The IMDS consists of high-quality measurements archived each minute, a data visualization tool, and a web-based capability. The operators recommend similar technology be adopted in other buildings. The IMDS has been used to identify and correct a series of control problems. It has also allowed the operators to make more effective use of the building control system, freeing up time to take care of other tenant needs. They believe they have significantly improved building comfort, potentially improving tenant health, and productivity. The reduction in hours to operate the building are worth about $20,000 per year, which could pay for the IMDS in about five years. A control system retrofit based on findings from the IMDS is expected to reduce energy use by 20 percent over the next year, worth over $30,000 per year. The main conclusion of the model-based chiller fault detection work is that steady-state models can be used as reference models to monitor chiller operation and detect faults. The ability of the IMDS to measure cooling load and chiller power to one-percent accuracy with a one-minute sampling interval permits detection of additional faults. Evolutionary programming techniques were also evaluated, showing promise in the detection of patterns in building data. We also evaluated two technology adoption processes, radical and routine. In routine adoption, managers enhance features of existing products that are already well understood. In radical adoption, innovative building managers introduce novel technology into their organizations without using the rigorous payback criteria used in routine innovations.%I CEC/CIEE %8 10/1999 %G eng %2 LBNL-44453 %3
Commissioning & Diagnostics%$
Commercial Building Systems Group%]
y%0 Report %D 1999 %T Phillip Burton Federal Building: EMCS Retrofit Analysis %A Richard C. Diamond %A Tim I. Salsbury %A Geoffrey C. Bell %A Yu Joe Huang %A Osman Sezgen %A Richard Mazzucchi %A Jeff Romberger %X
This report presents the interim results of analyses carried out in the Phillip Burton Federal Building in San Francisco from 1996 to 1998. The building is the site of a major demonstration of the BACnet communication protocol. The energy management and control systems (EMCS) in the building were retrofitted with BACnet compatible controllers in order to integrate certain existing systems on one common network. In this respect, the project has been a success. Interoperability of control equipment from different manufacturers has been demonstrated in a real world environment.
Besides demonstrating interoperability, the retrofits carried out in the building were also intended to enhance control strategies and capabilities, and to produce energy savings. This report presents analyses of the energy usage of HVAC systems in the building, control performance, and the reaction of the building operators. The report does not present an evaluation of the performance capabilities of the BACnet protocol. A monitoring system was installed in the building that parallels many of the EMCS sensors and data were archived over a three-year period. We defined pre-retrofit and post-retrofit periods and analyzed the corresponding data to establish the changes in building performance resulting from the retrofit activities.
We also used whole-building energy simulation (DOE-2) as a tool for evaluating the effect of the retrofit changes. The results of the simulation were compared with the monitored data. Changes in operator behavior were assessed qualitatively with questionnaires.
The report summarizes the findings of the analyses and makes several recommendations as to how to achieve better performance. We maintain that the full potential of the EMCS and associated systems is not being realized. The reasons for this are discussed along with possible ways of addressing this problem. We also describe a number of new technologies that could benefit systems of the type found in the Philip Burton Federal Building.%8 03/1999 %G eng %1
1.1%2 LBNL-43256 %& Chapter %0 Journal Article %J Philosophical Magazine Part B %D 1999 %T Reflective surfaces for cooler buildings and cities %A Melvin Pomerantz %A Hashem Akbari %A Paul H. Berdahl %A Steven J. Konopacki %A Haider Taha %A Arthur H. Rosenfeld %K cool roof %K Heat Island %X
Many roofs and pavements are dark coloured. In warm and sunny climates these surfaces become hot by absorbing sunlight. This can have the undesirable consequences of increasing the heat flow into the building beneath the hot roofs, which then increases the demand for air conditioning. The hot surfaces also heat the outside air, again increasing air conditioning demand but also increasing the concentration of ozone (smog). We estimate the benefits of replacing (as part of routine maintenance) the present dark surfaces with more reflective surfaces. We conclude that it is a practical way to save energy and to reduce smog in warm climates.%B Philosophical Magazine Part B %V 79 %P 1457-1476 %G eng %R 10.1080/13642819908216984 %0 Journal Article %J Journal of Applied Physics %D 1999 %T Refractive Index Changes of Pd-Coated Magnesium Ianthanide Switchable Mirrors Upon Hydrogen Insertion %A Klaus von Rottkay %A Michael D. Rubin %A Peter A. Duine %X
The optical effect upon insertion of hydrogen into Pd-coated magnesium lanthanide switchable mirrors is investigated in terms of the changes of their complex refractive indices. A significant change in the optical constants of LnMg layers is seen between the as-deposited state and the dehydrided state after one cycle. Furthermore, the optical effect of switching the Pd cap layer to a PdH cap layer was determined. It is shown that the Pd layer mainly limits the visible transmittance of the hydrided stack to about 35%-40%. Whereas the extinction coefficient of dehydrided LnMg layers at 550 nm is between 2.2 and 3.1, it is as low 10-4 as in the transparent state. This is of great promise to applications requiring large optical contrast (e.g., optical switches).%B Journal of Applied Physics %V 85 %P 408-413 %8 01/1999 %G eng %N 1 %1
Windows and Daylighting Group%2 LBNL-41976 %& 408 %R 10.1063/1.369399 %0 Journal Article %J Applied Physics Letters %D 1999 %T Solid State Gadolinium-Magnesium Hydride Optical Switch %A Robert D. Armitage %A Michael D. Rubin %A Thomas J. Richardson %A Nada O'Brien %A Yong Chen %X
The optical switching properties of gadolinium-magnesium hydride have been demonstrated in a solid-state electrochromic device. With positive polarization of the hydride electrode, the visible reflectance approaches 35% with virtually zero transmission, while with negative polarization, the visible transmission exceeds 25% at 650 nm. The switching is reversible, with intermediate optical properties between the transparent and reflecting states.%B Applied Physics Letters %V 75 %P 1863-1865 %8 09/1999 %G eng %U http://dx.doi.org/10.1063/1.124853 %N 13 %1
Windows and Daylighting Group%2 LBNL-43417 %& 1863 %0 Report %D 1998 %T Advanced Lighting Program Development (BG9702800) Final Report %A Francis M. Rubinstein %A Stephen G. Johnson %X
The report presents a long-range plan for a broad-based, coordinated research, development and market transformation program for reducing the lighting energy intensities in commercial and residential buildings in California without compromising lighting quality. An effective program to advance lighting energy efficiency in California must be based on an understanding that lighting is a mature field and the lighting industry has developed many specialized products that meet a wide variety of light needs for different building types. Above all else, the lighting field is diverse and there are applications for a wide range of lighting products, systems, and strategies. Given the range of existing lighting solutions, an effective energy efficient lighting research portfolio must be broad-based and diverse to match the diversity of the lighting market itself. The belief that there is one solution — a magic bullet, such as a better lamp, for example — that will propel lighting efficiency across all uses to new heights is, in our opinion, an illusion. A multi-path program is the only effective means to raising lighting efficiency across all lighting applications in all building types.
This report presents a list of 27 lighting technologies and concepts (key activities) that could form the basis of a coordinated research and market transformation plan for significantly reducing lighting energy intensities in California buildings. The total 27 key activities into seven broad classes as follows:
Each of the above technology classes is discussed in terms of background, key activities, and the energy savings potential for the state. The report concludes that there are many possibilities for targeted research, development, and market transformation activities across all sectors of the building lighting industry. A concerted investment by the state to foster efficiency improvements in lighting systems in commercial and residential buildings would have a major positive impact on energy use and environmental quality in California.%G eng %L LBNL-41679 %1
Lighting Systems Group%2 LBNL-41679 %0 Journal Article %J ASHRAE Transactions %D 1998 %T Comparison of North American and U.K. Cooling Load Calculation Procedures - Methodology %A Jeffrey D. Spitler %A Simon J. Rees %A Philip Haves %X This paper describes the methodology used in a quanti- tative comparison between the current North American and United Kingdom cooling load calculation methods. Three calculation methods have been tested as part of a joint ASHRAE/CIBSE research project: the ASHRAE heat balance method and radiant time series method and the admittance method, used in the U.K. A companion paper (Rees et al.1998) describes the results of the study. The quantitative comparison is primarily organized as a parametric study—each building zone/weather day combination compared may be thought of as a combination of various parameters, e.g., exterior wall type, roof type, glazing area, etc. Specifically, this paper describes the overall organization of the study, the parameters and parameter levels that can be varied, and the tools developed to create input files, automate the load calculations, and extract the results. A brief descrip- tion of the cooling load calculation procedure implementa- tions is also given. The methodology presented and the tools described could also be used to make comparisons between other calculation methods. %B ASHRAE Transactions %V 104 %P 47-61 %G eng %N 2 %& 47 %0 Journal Article %J ASHRAE Transactions %D 1998 %T Comparison of North American and U.K. Cooling Load Calculation Procedures - Results %A Simon J. Rees %A Jeffrey D. Spitler %A Philip Haves %X Calculation of design cooling loads is of critical concern to designers of HVAC systems. The work reported here has been carried out under a joint ASHRAE/CIBSE research project to compare design cooling calculation methods. Three calculation methods have been tested, the ASHRAE heat balance method and radiant time series method, and the admit- tance method, used in the U.K. The results presented in this paper show the general trends in over/underprediction of peak load in the simplified methods compared to the heat balance method. The performance of the simplified methods is explained in terms of some of the underlying assumptions in the methods and by reference to specific examples. %B ASHRAE Transactions %V 104 %P 36-46 %G eng %N 2 %& 36 %0 Journal Article %J Energy and Buildings %D 1998 %T Cool communities: strategies for heat island mitigation and smog reduction %A Arthur H. Rosenfeld %A Hashem Akbari %A Joseph J. Romm %A Melvin Pomerantz %K Heat Island %K urban heat island %X
Adopting our 'cool communities' strategies of reroofing and repaying in lighter colors and planting shade trees can effect substantial energy savings, directly and indirectly. In our target city of Los Angeles, annual residential air-conditioning (A/C) bills can be reduced directly by about US$100 M and, because these strategies serve to cool the air in the Los Angeles basin and reduce smog exceedance levels by about 10%, an additional savings of US$70 M in indirect cooling and US$360 M in smog-reduction benefits—a total savings of about US$1/2 B per year—is possible. Trees are most effective if they shade buildings, but the savings are significant even if they merely cool the air by evapotranspiration. In Los Angeles, avoided peak power for air conditioning can reach about 1.5 GW (more than 15% of the city's air conditioning). Generalized to the entire US, we estimate that 25 GW can be avoided with potential annual benefits of about US$5B by the year 2015. Recent steps taken by cities in the warm half of US towards adoption of cool communities include
Other step underway include
A fundamental premise of lighting is that light has value. This is easy to show when the choice is between no light and some light. When the choice is between some light and more light, it is much more difficult to demonstrate. Because of this difficulty, lighting recommendations have been based on consensus judgments of the value of light. There is no formal connection between these judgments and the basic premise upon which they are founded so they are not guaranteed optimal.
In this paper, we report on a successful attempt to formally analyze a practical problem: an evaluation of the relative economics of lumen maintenance control system vs the standard no-controls system. We digress briefly to describe a lumen maintenance control system.%B Journal of the Illuminating Engineering Society %V 28 %P 113-126 %G eng %L LBNL-40945 %1
Lighting Systems Group%2 LBNL-40945 %0 Conference Paper %B 1998 ACEEE Summer Study on Energy Efficiency in Buildings %D 1998 %T Creating Markets for New Products to Replace Incandescent Lamps: The International Experience %A Francis M. Rubinstein %A Nils Borg %A Noah Horowitz %A Tracy Narel %A E. Thomas Morehouse Jr. %X
Since the summer of 1995, several organizations have been in pursuit of what many consider the Holy Grail of lighting technology — a low-cost, drop-in, energy-efficient replacement for the incandescent lamp. This paper summarizes the international experience in attempting to catalyze the commercialization of a mass-market replacement product that could have a major impact on residential lighting energy consumption in U.S. and EU homes.
The technology procurement effort was originally spearheaded by the U.S. Federal Government through a loose collaboration between the Department of Defense (DOD), the Environmental Protection Agency (EPA) and the Department of Energy (DOE). The DOD agreed to serve as the anchor buyer for a low-cost, drop-in replacement product for standard-sized light bulbs that provide at least 30% energy savings compared to traditional incandescent lamps. In parallel to the U.S. effort, the International Energy Agency launched a cooperative technology procurement effort by assembling large buyers groups in Finland, the Netherlands, Sweden, and the United Kingdom to pull a similar efficient lighting product into the European market. The lukewarm response from lamp manufacturers to these two technology procurement efforts illustrates the challenges of transforming residential lighting from incandescent to efficient lighting.%B 1998 ACEEE Summer Study on Energy Efficiency in Buildings %C Pacific Grove, California %8 08/1998 %G eng %L LBNL-43782 %1
Lighting Systems Group%2 LBNL-43782 %0 Report %D 1998 %T Demonstration of energy savings of cool roofs %A Steven J. Konopacki %A Lisa M. Gartland %A Hashem Akbari %A Leo I. Rainer %K Case Studies %K Heat Island %X
Dark roofs raise the summertime air-conditioning demand of buildings. For highly-absorptive roofs, the difference between the surface and ambient air temperatures can be as high as 90 °F, while for highly-reflective roofs with similar insulative properties, the difference is only about 20 °F. For this reason, cool roofs are effective in reducing cooling energy use. Several experiments on individual residential buildings in California and Florida show that coating roofs white reduces summertime average daily air-conditioning electricity use from 2-63%.
This demonstration project was carried out to address some of the practical issues regarding the implementation of reflective roofs in a few commercial buildings. The authors monitored air-conditioning electricity use, roof surface temperature, plenum, indoor, and outdoor air temperatures, and other environmental variables in three buildings in California: two medical office buildings in Gilroy and Davis and a retail store in San Jose.
Coating the roofs of these buildings with a reflective coating increased the roof albedo from an average of 0.20-0.60. The roof surface temperature on hot sunny summer afternoons fell from 175 °F-120 °F after the coating was applied. Summertime average daily air-conditioning electricity use was reduced by 18% (6.3 kWh/1000ft2) in the Davis building, 13% (3.6 kWh/1000ft2) in the Gilroy building, and 2% (0.4 kWh/1000ft2) in the San Jose store.
In each building, a kiosk was installed to display information from the project in order to educate and inform the general public about the environmental and energy-saving benefits of cool roofs. They were designed to explain cool-roof coating theory and to display real-time measurements of weather conditions, roof surface temperature, and air-conditioning electricity use.%8 06/1998 %G eng %2 LBNL-40673 %R 10.2172/296885 %0 Conference Paper %B 1998 ACEEE Summer Study on Energy Efficiency in Buildings %D 1998 %T Developing Energy-Efficiency Packages for New Production Homes %A Richard E. Brown %A Celina S. Atkinson %A Jeffrey L. Warner %A Judy A. Roberson %A Marla C. Sanchez %A Sarah E. Bretz %A Jonathan G. Koomey %B 1998 ACEEE Summer Study on Energy Efficiency in Buildings %I American Council for an Energy Efficient Economy, Washington DC %C Asilomar, CA %8 08/1998 %G eng %2 LBNL-41561 %0 Conference Paper %B 1998 ACEEE Summer Study on Energy Efficiency in Buildings %D 1998 %T Development and Testing of an Information Monitoring and Diagnostics System for Large Commercial Buildings %A Mary Ann Piette %A Lisa M. Gartland %A Satkartar T. Khalsa %A Peter Rumsey %A Eng Lock Lee %A Anthony Sebald %A Christine Shockman %X
Large commercial buildings generally do not operate at economically achievable levels of energy efficiency. Performance monitoring projects have shown whole-building energy savings of 20% or more through improved operation and maintenance practices. The opportunity for O&M savings is related to systemic problems associated with the lack of feedback available from current Energy Management and Control Systems (EMCS). Today's EMCS are designed for control, with limited capabilities in sensing, archiving, data analysis, diagnostics, and data visualization. This paper discusses a multi-year, multi-institutional project to develop and demonstrate an Information Monitoring and Diagnostics System (IMDS). The system is designed to address common O&M problems and the needs of office building owners and property managers to address these problems. The IMDS includes about 50 points of whole-building and cooling plant data, plus a set of standard diagnostics plots to evaluate key performance metrics and curves. Five unique features of the project are (1) sophisticated building operators and engineers as users, (2) permanent installation, (3) high-quality sensing, (4) high-frequency data archives, and (5) top-down design (i.e., whole building, system, and component data). The system does not provide control functions. We review the installation and early results from the use of the IMDS. An office building demonstration site was selected because of the technical reputation and interest of the chief engineer and on-site operator. We also discuss the technology adoption process and decisions involved in such innovations.%B 1998 ACEEE Summer Study on Energy Efficiency in Buildings %S Proceedings of the 1998 ACEEE Summer Study on Energy Efficiency in Buildings %C Pacific Grove, CA %G eng %L LBNL-41926 %2 LBNL-41926 %4
August 23-28, 1998%$
Commercial Building Systems%]
y%0 Report %D 1998 %T Early Results and Field Tests of an Information Monitoring and Diagnostic System for Commercial Buildings: Phase 2 Project Report %A Mary Ann Piette %A Satkartar T. Khalsa %A Peter Rumsey %A Kristopher L. Kinney %A Eng Lock Lee %A Anthony Sebald %A Christine Shockman %X
Large commercial buildings generally do not operate at optimal levels of energy efficiency. Performance monitoring projects have shown whole-building energy savings of 20% or more through improved operation and maintenance (O&M) practices. The opportunity for O&M savings is related to many problems, such as the lack of initial commissioning and the lack of feedback available from controls systems on the performance of building systems and components. Even greater energy savings can be achieved with aggressive retrofits.
This report discusses Phase 2 of a multi-year, multi-institutional project to develop and demonstrate an Information Monitoring and Diagnostics System (IMDS). The first phase of the project was a detailed scoping study which included identifying both a group of innovative property managers for collaboration and their most important O&M problems. The key problem we identified is that building operators lack good information on major building systems. Phase 1 concluded that information tools currently in use in these buildings limit building managers' ability to assess their O&M practices in a comprehensive manner. We found systemic problems associated with the lack of feedback available from current Energy Management and Control Systems (EMCS). Today's EMCSs are designed for control, with extremely limited capabilities in sensing, archiving, data analysis, diagnostics, and data visualization.
Based on Phase 1 we defined the following objectives for the remainder of the project:
Commissioning & Diagnostics%$
Commercial Building Systems Group%]
y%0 Journal Article %J Electrochimica Acta %D 1998 %T Effect of Hydrogen Insertion on the Optical Properties of PD-Coated Magnesium Lanthanides %A Klaus von Rottkay %A Michael D. Rubin %A Franck Michalak %A Robert D. Armitage %A Thomas J. Richardson %A Jonathan L. Slack %A Peter A. Duine %X
Metallic magnesium lanthanide thin films upon insertion of hydrogen transform to a highly transparent hydride phase. With a Pd overlayer, the transformation can be produced either by electrochemical insertion of hydrogen or by exposing the film to hydrogen gas. Unlike amorphous oxide electrochromics, the transformation is accompanied by a large change in visible reflectance (about 50%). The optical switching effect in these materials is investigated in terms of changes in the complex refractive index as determined by variable-angle spectroscopic ellipsometric and normal-incidence radiometric measurements over the solar spectrum. Furthermore the optical effect of converting the Pd caplayer to Pd-H was determined. It is shown that the pd layer limits the visible transmittance of the hyrdrided stack to about 35-40%. Whereas the extinction coefficient of the dehydrided LnMg-layers at 550 nm is between 2.2 and 3.1, it is as low as 10-4 in the transparent state.%B Electrochimica Acta %C London, U.K. %8 9/1998 %G eng %L LBNL-42277 %1
Windows and Daylighting Group%2 LBNL-42277 %0 Journal Article %J Solar Energy Materials and Solar Cells %D 1998 %T Electrochromic lithium nickel oxide by pulsed laser deposition and sputtering %A Michael D. Rubin %A Shi-Jie Wen %A Thomas J. Richardson %A John B. Kerr %A Klaus von Rottkay %A Jonathan L. Slack %K Lithium nickel oxide %K pulsed laser deposition %K sputtering %X
Thin films of lithium nickel oxide were deposited by sputtering and pulsed laser deposition (PLD) from targets of pressed LiNiO2 powder. The composition and structure of these films were analyzed using a variety of techniques, such as nuclear-reaction analysis, Rutherford backscattering spectrometry (RBS), X-ray diffraction, infrared spectroscopy, and atomic-force microscopy. Crystalline structure, surface morphology and chemical composition of LixNi1−xO thin films depend strongly on deposition oxygen pressure, temperature as well as substrate–target distance. The films produced at temperatures lower than 600°C spontaneously absorb CO2 and H2O at their surface once they are exposed to the air. The films deposited at 600°C proved to be stable in air over a long period. Even at room temperature the PLD films are denser and more stable than sputtered films. RBS determined the composition of the best films to be Li0.5Ni0.5O deposited by PLD at 60 mTorr O2 pressure. Electrochemical tests show that the films exhibit excellent reversibility in the range 1.0–3.4 V versus lithium. Electrochemical formatting which is used to develop electrochromism in other films is not needed for the stoichiometric films. The optical transmission range is almost 70% at 550 nm for 150 nm-thick films. Devices made from these films were analyzed using novel reference electrodes and by disassembling after cycling.%B Solar Energy Materials and Solar Cells %V 54 %P 59-66 %8 07/1998 %G eng %N 1-4 %1
Windows and Daylighting Group%2 LBNL-39411 %& 59 %R 10.1016/S0927-0248(97)00223-7 %0 Journal Article %J Electrochimica Acta %D 1998 %T Electrochromic Lithium Nickel Oxide Thin Films by RF-Sputtering from a LiNiO2 Target %A Franck Michalak %A Klaus von Rottkay %A Thomas J. Richardson %A Jonathan L. Slack %A Michael D. Rubin %X
Thin films of lithium nickel oxide were deposited by rf sputtering from a stoichiometric LiNiO2 target. The composition and structure of these films depended on the oxygen pressure during deposition (sputtering gas is Argon), and, to a certain extent, the target history. The sputtering geometry, i.e. the substrate to target distance and the sputtering angle were also critical. the films exhibit excellent reversibility in the potential range 1.1V to 3.8 V vs Li/Li+ and could be cycled in a liquid electrolyte half cell for more than 3000 cycles with a switching range ΔTvis close to 70%. The coloration efficiency in the visible was typically -30 to -40 cm2 C-1. The switching performance of a device utilizing a lithium nickel oxide film as counter electrode for a tungsten oxide electrochromic film is reported.%B Electrochimica Acta %V 44 %P 3085-3092 %G eng %L LBNL-42276 %1
Windows and Daylighting Group%2 LBNL-42276 %0 Journal Article %J Applied Optics %D 1998 %T Ellipsometry on Sputter Deposited Tin Oxide Films: Optical Constants Versus Stoichiometry Hydrogen Content, and Amount of Electrochemically Intercalated Lithium %A Jan Isidorsson %A Claes G. Granqvist %A Klaus von Rottkay %A Michael D. Rubin %X
Tin oxide thin films were deposited by reactive radio-frequency magnetron sputtering onto In2O3:Sn coated and bare glass substrates. Optical constants in the 300-2500 nm wavelength range were determined by a combination of variable-angle spectroscopic ellipsometry and spectrophotometric transmittance measurements. Surface roughness was modeled from optical measurements and compared with atomic-force microscopy. The two techniques gave consistent results. The fit between experimental optical data and model results could be significantly improved when it was assumed that the refractive index of the Sn oxide varied across the film thickness. Varying the oxygen partial pressure during deposition made it possible to obtain films whose complex refractive index changed at the transition from SnO to SnO2. An addition of hydrogen gas during sputtering led to lower optical constants in the full spectral range in connection with a blue shift of the band gap. Electrochemical intercalation of lithium ions into the Sn oxide films raised their refractive index and enhanced their refractive-index gradient.%B Applied Optics %V 37 %P 7734-7741 %G eng %L LBNL-41820 %1
Windows and Daylighting Group%2 LBNL-41820 %0 Conference Paper %B ASHRAE/DOE/BTECC Conference, Thermal Performance of the Exterior Envelopes of Buildings VII %D 1998 %T Energy and Daylight Performance of Angular Selective Glazings %A Robert Sullivan %A Liliana O. Beltran %A Eleanor S. Lee %A Michael D. Rubin %A Stephen E. Selkowitz %X
This paper presents the results of a study investigating the energy and daylight performance of anisotropic angular selective glazings. The DOE-2.1E energy simulation program was used to determine the annual cooling, lighting and total electricity use, and peak electric demand. RADIANCE, a lighting simulation program, was used to determine daylight illuminance levels and distribution. We simulated a prototypical commercial office building module located in Blythe, California. We chose three hypothetical conventional windows for comparison: a single-pane tinted window, a double-pane low-E window, and a double-pane spectrally selective window. Daylighting controls were used. No interior shades were modeled in order to isolate the energy effects of the angular selective glazing. Our results show that the energy performance of the prototype angular selective windows is about the same as conventional windows for a 9.14 m (30 ft) deep south-facing perimeter zone with a large-area window in the hot, sunny climate of Blythe. It is theoretically possible to tune the angular selectivity of the glazing to achieve annual cooling energy reductions of 18%, total electricity use reductions of 15%, and peak electric demand reductions of 11% when compared to a conventional glazing with the same solar-optical properties at normal incidence. Angular selective glazings can provide more uniformly distributed daylight, particularly in the area next to the window, which will result in a more visually comfortable work environment.%B ASHRAE/DOE/BTECC Conference, Thermal Performance of the Exterior Envelopes of Buildings VII %C Clearwater Beach, FL %8 12/1998 %G eng %L LBNL-41694 %1
Windows and Daylighting Group%2 LBNL-41694 %0 Conference Proceedings %B ACEEE %D 1998 %T The ENERGY STAR Purchasing Initiative %A Jennifer R. Dolin %A Ned R. Raynolds %X
Federal, state, and local governments could save at least $139 million annually by reducing energy waste through the purchase and use of energy-efficient products. Reducing this waste would reduce annual greenhouse gas emissions by 4.1 million metric tons of carbon (MMTCs) by the year 2010; the equivalent of planting an area of trees the size of Yellowstone National Park. In addition, with $50-70 billion in purchasing power for energy-related products, specifying energy efficiency could significantly shift the market for these products.
The Federal government recently launched the ENERGY STAR® Purchasing Initiative to channel the purchasing power of state and local governments -and its environmental impact- in the direction of energy-efficient products to capture significant environmental benefits and increase the demand in the marketplace. Part of this effort studied why governments don't currently procure the most efficient products, and attempted to identify the changes that would be necessary to allow many governments to do so. Some of the initial barriers to energy-efficient procurement that were found are:
• Lack of information about the availability of energy-efficient products;
• Split incentives, where the agency purchasing the products do not pay for the utility bills directly and, therefore, have little interest, or incentive, to save energy;
• Misinformation about the benefits of energy efficiency;
• Energy efficiency not seen as a value-added aspect of procurement;
• Budget constraints; and
• Lowest first-cost bias.
This paper will present the results of this study and describe the mechanisms that will be put into place to address each of these barriers.%B ACEEE %S ACEEE 1998 Summer Study on Energy Efficiency in Buildings %V Volume 7 %2 LBNL-187936 %0 Journal Article %J Solar Energy %D 1998 %T Models for the Angle-Dependent Optical Properties of Coated Glazing Materials %A Michael D. Rubin %A Rebecca Powles %A Klaus von Rottkay %X
Optical transmittance and reflectance of window materials can be measured accurately at normal incidence using standard equipment. Sunlight often strikes at angles for which the transmittance and reflectance are significantly different from their values at normal incidence. A reliable procedure for extrapolating from normal properties to oblique properties is thus needed for accurate annual energy performance calculations and product comparisons. The structural models for the materials are greatly constrained by the limited amount of data that is usually available. For monolithic materials such as uncoated glass or plastic substrates it is possible to solve directly for the optical indices and then apply Fresnels equation to obtain the oblique properties. For coated glass, the situation is more complex, but a numerical solution is often possible. First, detailed optical models were constructed and accurate angle-dependent data were generated for a wide selection of coated glazing materials. Then, a set of very simple thin-film models were chosen that would converge given a limited amount of data. At 60 degree incidence, the monolithic model was often accurate to within 2% but frequently deviated farther up to 8%. The single-layer thin-film model fared little better. Highly constrained multilayer models often deviated less than 1% although convergence became increasingly specific to similar coating types.%B Solar Energy %V 66 %P 267-276 %G eng %L LBNL-40705 %1
Windows and Daylighting Group%2 LBNL-40705 %0 Journal Article %J Applied Optics %D 1998 %T Optical Constants of Sputter-Deposited Ti-Ce Oxide and Zr-Ce Oxide Films %A Monica Veszelei %A Lisen Kullman %A Claes G. Granqvist %A Klaus von Rottkay %A Michael D. Rubin %X
Films of Ti oxide, Zr oxide, Ce oxide, Ti-Ce oxide, and Zr-Ce oxide were made by means of reactive dc magnetron sputtering in a multitarget arrangement. The films were characterized by x-ray diffraction and electrochemical measurements, both techniques being firmly connected to stoichiometric information. The optical constants n and k were evalued from spectrophotometry and from variable-angle spectroscopic ellipsometry. The two analyses gave consistent results. It was found that n for the mixed-oxide films varied smoothly between the values for the pure oxides, whereas k in the band-gap range showed characteristic differences between Ti-Ce oxide and Zr-Ce oxide. It is speculated that this difference is associated with structural effects.%B Applied Optics %V 37 %P 5993-6001 %8 09/1998 %G eng %N 25 %1
Windows and Daylighting Group%2 LBNL-42059 %& 5993 %R 10.1364/AO.37.005993 %0 Journal Article %J Atmospheric Environment %D 1998 %T Practical issues for using solar-reflective materials to mitigate urban heat islands %A Sarah E. Bretz %A Hashem Akbari %A Arthur H. Rosenfeld %K Cool Pavements %K Heat Island %X
Solar-reflective or high-albedo, alternatives to traditionally absorptive urban surfaces such as rooftops and roadways can reduce cooling energy use and improve urban air quality at almost no cost. This paper presents information to support programs that mitigate urban heat islands with solar-reflective surfaces: estimates of the achievable increase in albedo for a variety of surfaces, issues related to the selection of materials and costs and benefits of using them. As an example, we present data for Sacramento, California. In Sacramento, we estimate that 20% of the 96 square mile area is dark roofing and 10% is dark pavement. Based on the change in albedo that is achievable for these surfaces, the overall albedo of Sacramento could be increased by 18%, a change that would produce significant energy savings and increase comfort within the city. Roofing market data indicate which roofing materials should be targeted for incentive programs. In 1995, asphalt shingle was used for over 65% of residential roofing area in the U.S. and 6% of commercial. Built-up roofing was used for about 5% of residential roofing and about 30% of commercial roofing. Single-ply membranes covered about 9% of the residential roofing area and over 30% of the commercial area. White, solar-reflective alternatives are presently available for these roofing materials but a low-first-cost, solar-reflective alternative to asphalt shingles is needed to capture the sloped-roof market. Since incoming solar radiation has a large non-visible component, solar-reflective materials can also be produced in a variety of colors.%B Atmospheric Environment %V 32 %P 95-101 %G eng %R 10.1016/S1352-2310(97)00182-9 %0 Conference Paper %B IESNA 1998 Annual Conference %D 1998 %T Preliminary Results from an Advanced Lighting Controls Testbed %A Francis M. Rubinstein %A Judy D. Jennings %A Doug A. Avery %A Steven L. Blanc %X
Preliminary results from a large-scale testbed of advanced lighting control technologies at the Phillip Burton Federal Building at 450 Golden Gate Ave. in San Francisco are presented. The first year objective of this project is to determine the sustainable energy savings and cost-effectiveness of different lighting control technologies compared to a portion of the building where only minimal controls are installed. The paper presents the analyzed results from six months of tests focused on accurately characterizing the energy savings potential of one type of daylight-linked lighting controls compared to the lighting in similar open-planned areas without dimming controls. After analyzing a half years data, we determined that the annual energy savings for this type of daylight-linked controls was 41% and 30% for the outer rows of lights on the South and North sides of the building, respectively. The annual energy savings dropped to 22% and 16% for the second row of lights for the South and North, respectively, and was negligible for the third rows of lights.%B IESNA 1998 Annual Conference %C San Antonio, TX %8 08/1998 %G eng %1
Lighting Systems Group%2 LBNL-41633 %0 Report %D 1998 %T Recommended Ventilation Strategies for Energy-Efficient Production Homes %A Judy A. Roberson %A Richard E. Brown %A Jonathan G. Koomey %A Steve E. Greenberg %K Enduse %K Energy End-Use Forecasting %K energy star homes %K EUF %K ventilation %X
This report evaluates residential ventilation systems for the U.S. Environmental Protection Agency's (EPA's) ENERGY STAR® Homes program and recommends mechanical ventilation strategies for new, low-infiltration, energy-efficient, single-family, ENERGY STAR production (site-built tract) homes in four climates: cold, mixed (cold and hot), hot humid, and hot arid. Our group in the Energy Analysis Department at Lawrence Berkeley National Lab compared residential ventilation strategies in four climates according to three criteria: total annualized costs (the sum of annualized capital cost and annual operating cost), predominant indoor pressure induced by the ventilation system, and distribution of ventilation air within the home. The mechanical ventilation systems modeled deliver 0.35 air changes per hour continuously, regardless of actual infiltration or occupant window-opening behavior. Based on the assumptions and analysis described in this report, we recommend independently ducted multi-port supply ventilation in all climates except cold because this strategy provides the safety and health benefits of positive indoor pressure as well as the ability to dehumidify and filter ventilation air. In cold climates, we recommend that multi-port supply ventilation be balanced by a single-port exhaust ventilation fan, and that builders offer balanced heatrecovery ventilation to buyers as an optional upgrade. For builders who continue to install forced-air integrated supply ventilation, we recommend ensuring ducts are airtight or in conditioned space, installing a control that automatically operates the forced-air fan 15-20 minutes during each hour that the fan does not operate for heating or cooling, and offering ICM forced-air fans to home buyers as an upgrade.%I Lawrence Berkeley National Laboratory %C Berkeley, CA %8 12/1998 %@ LBNL-40378 %G eng %2 LBNL-40378 %0 Conference Paper %B 1998 ACEEE Summer Study on Energy Efficiency in Buildings %D 1998 %T Recommended Ventilation Strategies for New Energy-Efficient Production Homes %A Judy A. Roberson %A Richard E. Brown %A Jonathan G. Koomey %A Jeffrey L. Warner %A Steve E. Greenberg %B 1998 ACEEE Summer Study on Energy Efficiency in Buildings %I American Council for an Energy Efficient Economy, Washington DC %C Asilomar, CA %8 08/1998 %G eng %2 LBNL-42680 %0 Conference Paper %B ACEEE 1998 Summer Study on Energy Efficiency in Buildings %D 1998 %T State-of-the-Art Software for Window Energy-Efficiency Rating and Labeling %A Dariush K. Arasteh %A Elizabeth U. Finlayson %A Yu Joe Huang %A Charlie Huizenga %A Robin Mitchell %A Michael D. Rubin %X
Measuring the thermal performance of windows in typical residential buildings is an expensive proposition. Not only is laboratory testing expensive, but each window manufacturer typically offers hundreds of individual products, each of which has different thermal performance properties. With over a thousand window manufacturers nationally, a testing-based rating system would be prohibitively expensive to the industry and to consumers.
Beginning in the early 1990s, simulation software began to be used as part of a national program for rating window U-values. The rating program has since been expanded to include Solar Hear Gain Coefficients and is now being extended to annual energy performance.
This paper describes four software packages available to the public from Lawrence Berkeley National Laboratory (LBNL). These software packages are used to evaluate window thermal performance: RESFEN (for evaluating annual energy costs), WINDOW (for calculating a products thermal performance properties), THERM (a preprocessor for WINDOW that determines two-dimensional heat-transfer effects), and Optics (a preprocessor for WINDOWs glass database).
Software not only offers a less expensive means than testing to evaluate window performance, it can also be used during the design process to help manufacturers produce windows that will meet target specifications. In addition, software can show small improvements in window performance that might not be detected in actual testing because of large uncertainties in test procedures.%B ACEEE 1998 Summer Study on Energy Efficiency in Buildings %C Pacific Grove, CA %8 08/1998 %G eng %L LBNL-42151 %1
Windows and Daylighting Group%2 LBNL-42151 %0 Report %D 1998 %T Technology and greenhouse gas emissions: An integrated analysis using the LBNL-NEMS model %A Jonathan G. Koomey %A R. Cooper Richey %A John A. Laitner %A Robert J. Markel %A Chris Marnay %K Enduse %K Energy End-Use Forecasting %K EUF %X
The common perception among many policy makers and industry leaders is that the twin objectives of reducing greenhouse gas emissions and promoting a more competitive economy are inherently contradictory. Many believe that anything done to lower such emissions will necessarily restrict economic activity. Others argue that if the economy moves forward at current levels of efficiency, growth in greenhouse gas emissions will be inevitable and the global climate will be seriously damaged. Because of the "unavoidable tradeoff" between these two objectives, the various industry, government and environmental groups wage a constant policy battle over which objective merits the greater support. From a perspective of cost-effective investments in technology, however, it becomes increasingly clear that these two goals are not at all contradictory. The reason is that the U.S. economy falls short of an optimal level of overall carbon efficiency. Figure ES-1 on the following page illustrates the different points of view in a schematic way. The curves on this graph represent different "Production Possibility Frontiers" that characterize the relationship between carbon emissions mitigation and economic activity. The frontier defines the outer boundary of what is feasible given a set of technologies and economic activity levels. Most modeling of the costs of reducing carbon emissions assumes that the reference case carbon intensity is on the frontier, and that any increase in carbon mitigation must also result in a decrease in Gross Domestic Product (this point of view corresponds to the curve labeled "Assumed Year 2010 Business-As-Usual Case Frontier"). Our analysis demonstrates that the "Actual Year 2010 Business-As-Usual Case Frontier" is further out than the assumed frontier, which means that both carbon mitigation and GDP can be increased at the same time, given the right set of policies and programs. In addition, since the frontier is a function of technology, and the cost of that technology is a function of policy choices made between now and 2010, taking aggressive actions now to reduce carbon emissions can actually move the frontier further out than it would be given the technologies that exist in the reference case. This possibility is represented by the curve labeled "Year 2010 Aggressive Implementation Case Frontier". This report describes an analysis of possible technology-based scenarios for the U.S. energy system that would result in both carbon savings and net economic benefits. We use a modified version of the Energy Information Administration's National Energy Modeling System (LBNL-NEMS) to assess the potential energy, carbon, and bill savings from a portfolio of carbon saving options. This analysis is based on technology resource potentials estimated in previous bottom-up studies, but it uses the integrated LBNL-NEMS framework to assess interactions and synergies among these options.%I Ernest Orlando Lawrence Berkeley National Laboratory %C Berkeley, CA %8 09/1998 %@ LBNL-42054, UC-000, EPA 430-R-98-021 %G eng %2 LBNL-42054 %0 Conference Paper %B Electrochemical Society: Molecular Functions of Electroactive Thin Films %D 1998 %T Tungsten-Vanadium Oxide Sputtered Films for Electrochromic Devices %A Thomas J. Richardson %A Klaus von Rottkay %A Jonathan L. Slack %A Franck Michalak %A Michael D. Rubin %X
Mixed vanadium and tungsten oxide films with compositions ranging from 0 to 100% vanadium (metals basis) were prepared by reactive sputtering from metallic vanadium and tungsten targets in an atmosphere of argon and oxygen. The vanadium content varied smoothly with the fraction of total power applied to the vanadium target. Films containing vanadium were more color neutral than pure tungsten oxide films, tending to gray-brown at high V fraction. The electrochromic switching performance of these films was investigated by in situ monitoring of their visible transmittance during lithium insertion/extraction cycling in a non-aqueous electrolyte (1M LiClO4 in PC). the solar transmittance and reflectance was measured ex-situ. Films with vanadium content greater than about 15%, exhibited a marked decrease in switching range. The coloration efficiencies followed a similar trend.%B Electrochemical Society: Molecular Functions of Electroactive Thin Films %C Boston, MA %V 98-26 %8 11/1998 %G eng %L LBNL-42381 %1
Windows and Daylighting Group%2 LBNL-42381 %0 Journal Article %J Thin Solid Films %D 1997 %T Analysis of Binary Electrochromic Tungsten Oxides with Effective Medium Theory %A Klaus von Rottkay %A Nilgün Özer %A Michael D. Rubin %A Thomas J. Richardson %X
Multicomponent oxides are of increasing interest for electrochromic electrodes. To reduce the large number of permutations in composition it would be useful to be able to predict the properties of the mixtures from the pure oxide components. WO3 mixed with V2O5 has been produced by a sol-gel technique in order to increase durability and color neutrality of conventional WO3 electrochromic coatings. Chemical composition was confirmed by Rutherford backscattering spectrometry (RBS). Surface morphology was analyzed by atomic force microscopy (AFM). Electrochromic performance of the films was tested by cyclic voltammetry with in-situ transmission control. Optical constants of vanadium tungsten oxides were determined over the whole solar spectrum. The measurements included variable angle spectroscopic ellipsometry and spectral transmittance and reflectance. An attempt is made to treat doped tungsten oxide as an effective medium consisting of a mixture of WO3 with V2O5. In the clear state, comparison of optical constants and thickness directly determined on the samples yields qualitative agreement with results from effective-medium analysis. The resulting component fraction also agrees as long as the film density does not deviate too much from the linearly interpolated value between the pure components. For the colored state, preferential trapping of electrons at one atom species hinders the application of effective medium theory.%B Thin Solid Films %V 308-309 %P 50-55 %G eng %L LBNL-40096 %1
Windows and Daylighting Group%2 LBNL-40096 %0 Conference Paper %B 4th European Conference on Energy-Efficient Lighting %D 1997 %T On the Calibration and Commissioning of Lighting Controls %A Francis M. Rubinstein %A Doug A. Avery %A Judy D. Jennings %A Steven L. Blanc %X
Lighting controls have the potential to capture significant energy savings in commercial buildings if properly specified, installed, commissioned and maintained. Proper commissioning is often absent in lighting projects and the lack of commissioning can significantly reduce a projects energy savings potential. The paper focuses on the importance of good commissioning practice for obtaining satisfactory performance from lighting control systems and discusses the difficulties of commissioning todays systems. Some practical suggestions for commissioning lighting controls is offered as well as advice to specifiers and early adopters to aid them in selecting controls that are most appropriate to their requirements.%B 4th European Conference on Energy-Efficient Lighting %C Copenhagen, Denmark %8 11/1997 %G eng %L LBNL-41010 %1
Lighting Systems Group%2 LBNL-41010 %0 Conference Proceedings %B Proceedings of the Second International Conference on Buildings and the Environment %D 1997 %T Cool buildings and cool communities %A Hashem Akbari %A Arthur H. Rosenfeld %K energy savings %K Heat Island %X
Analysis of temperature trends for the last 100 years in several large U. S. cities has indicated that since -1940 there has been a steady increase in downtown temperatures of 0.1-0.5DC per decade (-0.5°C for larger cities like Los Angeles and 0.1°C for smaller cities). Typically, electricity demand in cities increases by 2-4%/°C, hence, about 5-10% of the current urban electricity demand is spent to cool buildings just to compensate for the urban heat island effect. Downtown Los Angeles, for example, is now 3°C warmer than in 1940 leading to an increase in electricity demand of 1500 MW. In L.A., smoggy episodes are absent below about 21°C, but smog becomes unacceptable by 32°C, so a rise of 3°C, because of the heat island effects, can be significant. Urban trees and high-albedo surfaces can offset or reverse the heat island effect, and can potentially reduce the national energy use of air conditioning by 10% and save over $4B per year. The albedo of a city may be increased gradually if high-albedo surfaces are chosen to replace darker materials during routine maintenance of roofs and roads. Incentive programs, product labeling, and standards could promote the use of high-albedo materials for buildings and roads. Similar incentive-based programs need to be developed for urban trees.%B Proceedings of the Second International Conference on Buildings and the Environment %V 2 %P 301-308 %8 1997/june 9--12 %G eng %0 Conference Paper %B SPIE Proceedings %D 1997 %T Effective Medium Approximation of the Optical properties of electrochromic cerium-titanium oxide compounds %A Klaus von Rottkay %A Thomas J. Richardson %A Michael D. Rubin %A Jonathan L. Slack %K cerium titanium oxide %K effective medium theory %K electrochromic %K optical constants %X
Cerium titanium oxide samples derived from a solution have been compared against sputtered films over a wide range of different compositions. X-ray diffraction was used to investigate the structural properties of the compound material existing in a two-phase mixture MAO2-MBO2. The optical properties were evaluated over the whole solar spectrum by variable angle spectroscopic ellipsometry combined with spectrophutometry. The spectral complex refractive index was determined for CeO2 and TiO2, as well as for their compounds. To reduce the large number of permutations in composition of multi-component oxides it would be useful to be able to predict the properties of the mixtures from the pure oxide components. Therefore these results were compared to those obtained by effective medium theory utilizing the optical constants of CeO2 and TiO2. In order to investigate the performance as passive counter-electrode in Li+ based electrochromic devices the films were tested by cyclic voltammetry with in-situ transmission control. Chemical composition was measured by Rutherford backscattering spectrometry. Surface morphology was analyzed by atomic force microscopy.%B SPIE Proceedings %C San Diego, CA %V 3138 %P 19-Sep %8 07/1997 %G eng %L LBNL-40668 %1
Windows and Daylighting Group%2 LBNL-40668 %0 Report %D 1997 %T Energy Data Sourcebook for the U.S. Residential Sector %A Thomas P. Wenzel %A Jonathan G. Koomey %A Gregory J. Rosenquist %A Marla C. Sanchez %A James W. Hanford %K Enduse %K Energy End-Use Forecasting %K EUF %X
Analysts assessing policies and programs to improve energy efficiency in the residential sector require disparate input data from a variety of sources. This sourcebook, which updates a previous report, compiles these input data into a single location. The data provided include information on end-use unit energy consumption (UEC) values of appliances and equipment; historical and current appliance and equipment market shares; appliance and equipment efficiency and sales trends; appliance and equipment efficiency standards; cost vs. efficiency data for appliances and equipment; product lifetime estimates; thermal shell characteristics of buildings; heating and cooling loads; shell measure cost data for new and retrofit buildings; baseline housing stocks; forecasts of housing starts; and forecasts of energy prices and other economic drivers. This report is the essential sourcebook for policy analysts interested in residential sector energy use. The report can be downloaded from the Web at http://enduse.lbl.gov/Projects/RED.html. Future updates to the report, errata, and related links, will also be posted at this address.%I Lawrence Berkeley National Laboratory %C Berkeley, CA %8 09/1997 %@ LBNL-40297, UC-1600 %G eng %2 LBNL-40297 %0 Conference Paper %B 11th International Conference of Solid State Ionics %D 1997 %T Influence of stoichiometry on the electrochromic cerium-titanium oxide compounds %A Klaus von Rottkay %A Thomas J. Richardson %A Michael D. Rubin %A Jonathan L. Slack %A Lisen Kullman %K band gap %K charge capacity %K electrochromic cerium titanium oxide %K grain size %K optical constants %K rms roughness %K tio2 %X
CeO2-TiO2 finds use as passive counter-electrode in electrochromic devices. Thin films were produced by dc-sputtering in a wide range of compositions. Influence of total pressure and oxygen partial pressure on the optical constants of TiO2 was investigated. Slightly substoichiometric TiO2 films exhibit a red-shift of the bandgap. The TiO2 content in the compound essentially determines the degree of cathodical coloring upon Li+ intercalation. However, pure TiO2 films with comparable visible transmittance in the clear state behave differently during electrochemical cycling depending on oxygen stoichiometry. Films that are deposited at higher total pressure are more oxygen rich and require initial formatting until current voltage cycles become stable. CeO2-TiO2 films of intermediate compositions have the relatively highest charge capacity. Comparison with atomic force microscopy indicates a correlation of small grain size with high charge capacity.%B 11th International Conference of Solid State Ionics %C Honolulu, Hawaii %8 11/1997 %G eng %L LBNL-41550 %1
Windows and Daylighting Group%2 LBNL-41550 %0 Journal Article %J MIT Technology Review %D 1997 %T Painting the Town White—and Green %A Arthur H. Rosenfeld %A Joseph J. Romm %A Hashem Akbari %A Alan C. Lloyd %K cool roof %K Heat Island %X
On a summer afternoon, central Los Angeles registers temperatures typically 5°F higher than the surrounding suburban and rural areas. Hot roofs and pavements, baked by the sun, warm the air blowing over them. The resulting urban "heat island" causes discomfort, hikes air-conditioning bills, and accelerates the formation of smog.
Heat islands are found in many large cities, including Chicago, Washington, and (as the Olympic athletes and fans can attest) Atlanta. The effect is particularly well recognized in cities that quote two airport temperatures on the weather report. Thus Chicago-Midway airport is typically a few degrees hotter than suburban O'Hare, and the same difference applies between Washington National airport and Dulles.%B MIT Technology Review %V 100 %P 52-59 %G eng %U http://www.sfrc.ufl.edu/urbanforestry/Resources/PDF%20downloads/Rosenfeld_1997.pdf %N 2 %& 52 %0 Report %D 1997 %T Paving materials for heat island mitigation %A Melvin Pomerantz %A Hashem Akbari %A Allan Chen %A Haider Taha %A Arthur H. Rosenfeld %K Cool Pavements %K Heat Island %X
This report summarizes paving materials suitable for urban streets, driveways, parking lots and walkways. The authors evaluate materials for their abilities to reflect sunlight, which will reduce their temperatures. This in turn reduces the excess air temperature of cities (the heat island effect). The report presents the compositions of the materials, their suitability for particular applications, and their approximate costs (in 1996). Both new and resurfacing are described. They conclude that, although light-colored materials may be more expensive than conventional black materials, a thin layer of light-colored pavement may produce energy savings and smog reductions whose long-term worth is greater than the extra cost.%G eng %R 10.2172/291033 %0 Journal Article %J Materials Research Society Proceedings %D 1997 %T Pressure Controlled GaN MBE Growth Using a Hollow Anode Nitrogen Ion Source %A Michael S.H. Leung %A Ralf Klockenbrink %A Christian F. Kisielowski %A Hiroaki Fujii %A Joachim Krüger %A Sudhir G. Subramanya %A André Anders %A Zuzanna Liliental-Weber %A Michael D. Rubin %A Eicke R. Weber %E Joachim Krüger %X
GaN films were grown on sapphire substrates at temperatures below 1000 K utilizing a Hollow Anode nitrogen ion source. A Ga flux limited growth rate of ~0.5 μm/h is demonstrated. Active utilization of strain and the assistance of a nitrogen partial pressure during buffer layer growth are found to be crucial issues that can improve the film quality. The best films exhibit a full width at half maximum of the x-ray rocking curves of 80 arcsec and 1.85 meV for the excitonic photoluminescence measured at 4 K. A Volmer-Weber three dimensional growth mode and the spontaneous formation of cubic GaN inclusions in the hexagonal matrix are observed in the investigated growth temperature range. It is argued that this growth mode contributes to a limitation of the carrier mobility in these films that did not exceed 120 cm2/Vs through a minimum canier concentration of ~1015 cm-3 was achieved.%B Materials Research Society Proceedings %V 449 %G eng %N 221 %1
Windows and Daylighting Group%2 LBNL-39851 %! MRS Proceedings %R 10.1557/PROC-449-221 %0 Report %D 1997 %T Tips for Daylighting with Windows: The Integrated Approach %A Jennifer O'Conner %A Eleanor S. Lee %A Francis M. Rubinstein %A Stephen E. Selkowitz %X
These guidelines provide an integrated approach to the cost-effective design of perimeter zones in new commercial buildings. They function as a quick reference for designers through a set of easy steps and rules-of-thumb, emphasizing "how-to" practical details. References are given to more detailed sources of information, should the reader wish to go further.
No guidelines can answer all possible questions from all types of users. However, this document addresses the most commonly occurring scenarios. The guidance here is limited by the medium; short paper documents can only go so far in assisting a designer with a unique project. This document has been carefully shaped to best meet the needs of a designer when time does not permit a more extensive form of assistance.
The design method used in this document emphasizes that building decisions should be made within the context of the whole building as a single functioning system rather than as an assembly of distinct parts. This integrated design approach looks at the ramifications of each individual system decision on the whole building. For example, the glazing selection will have an effect on lighting, mechanical, and interior design. Therefore, the entire design team should participate in and influence this decision—which typically rests with the architect alone. The benefit of an integrated design approach is a greater chance of success towards long term comfort and sustained energy savings in the building.%G eng %1
Windows and Daylighting Group%2 LBNL-39945 %0 Report %D 1997 %T A Visibility Matching Tone Reproduction Operator for High Dynamic Range Scenes %A Gregory W. Larson %A Holly Rushmeier %A Christine Paitko %X
We present a tone reproduction operator that preserves visibility in high dynamic range scenes. Our method introduces a new histogram adjustment technique, based on the population of local adaptation luminances in a scene. To match subjective viewing experience, the method incorporates models for human contrast sensitivity, glare, spatial acuity and color sensitivity. We compare our results to previous work and present examples of our techniques applied to lighting simulation and electronic photography.%G eng %L LBNL-39882 %1
Lighting Systems Group%2 LBNL-39882 %0 Journal Article %J Solar Energy %D 1997 %T Window Optics %A Michael D. Rubin %A Klaus von Rottkay %A Rebecca Powles %X
Optical and radiative properties of glazing materials are primary inputs for determination of energy performance in buildings. This paper revisits the problem and reformulates the calculations to encompass a variety of solutions to practical problems in window optics. Properties of composite systems such as flexible films applied to rigid glazing and laminated glazing can be predicted from measurements on isolated components in air or other gases. Properties of a series of structures can be generated from those of a base structure. For example, the measured properties of a coated or uncoated substrate can be extended to a range of available substrate thicknesses without the need to measure each thickness. Similarly, a coating type could be transferred by calculation to any other substrate. A simple monolithic model for extrapolating from normal properties to oblique properties is shown to have sufficient accuracy for the purpose of annual energy performance calculations. A process is initiated to develop a reliable method for determination of effective indices suitable for more detailed spectral and directional optical calculations.%B Solar Energy %V 62 %P 149-161 %G eng %L LBNL-39911 %1
Windows and Daylighting Group%2 LBNL-39911 %0 Conference Paper %B 2nd International Meeting on Electrochromism %D 1996 %T Analysis of Durability in Lithium Nickel Oxide Electrochromic Materials and Devices %A Shi-Jie Wen %A John B. Kerr %A Michael D. Rubin %A Jonathan L. Slack %A Klaus von Rottkay %X
Thin films of lithium nickel oxide were deposited by sputtering and laser ablation from targets of pressed nickel oxide and lithium oxide powders. These films were assembled into electrochromic test devices with tungsten oxide as the opposite electrode and a polymer electrolyte. Analysis of the failure modes was carried out at several levels: The composition and structure of the films were examined before and after cycling using a variety of techniques, such as infrared spectroscopy, nuclear-reaction analysis, Rutherford backscattering spectrometry, x-ray diffraction and atomic force microscopy. Absorption of water vapor was found to be a major factor determining the cyclic stability of the films. A new technique is described for incorporating reference electrodes made from an electronically isolated corner into devices. This structure enabled identification of potential problems associated with a particular interface. Finally, some of the devices were disassembled and the components examined. For example, a small quantity of the polymer was extracted and studied by gas chromatography and mass spectroscopy. Small organic fragments were discovered which correspond to expected weak points in the polymer structures.%B 2nd International Meeting on Electrochromism %C San Diego, CA %8 10/1996 %G eng %L LBNL-39633 %1
Windows and Daylighting Group%2 LBNL-39633 %0 Journal Article %J Journal of the Illuminating Engineering Society %D 1996 %T Developing a Dynamic Envelope/Lighting Control System with Field Measurements %A Dennis L. DiBartolomeo %A Eleanor S. Lee %A Francis M. Rubinstein %A Stephen E. Selkowitz %X
The feasibility of an intelligent venetian blind/lighting control system was tested in a 1:3 scale model outdoors under variable sun and sky conditions. The control algorithm, block direct sun and meet the design workplane illuminance level, was implemented using commercially available and custom designed blind and lighting systems hardware. While blocking direct sunlight, the blinds were properly controlled to maintain the design workplane illuminance within a tolerance of -10%, +25% when there was sufficient daylight. When daylight levels alone were inadequate, the electric lighting control system maintained the design workplane illuminance. The electric lighting could be turned off if a user-specified time period at minimum power was exceeded. Lighting energy savings of 51-71% (southwest) and 37-75% (south) was attained for the period from 8:00 to 17:00 on clear sunny days, compared to a fixed, partially closed blind with the same lighting system. Practical details for implementation and commissioning are discussed. The impact of control variations, such as profile angle, time step interval, and control area, on energy demand is investigated.%B Journal of the Illuminating Engineering Society %V 26 %P 146-164 %8 05/1996 %G eng %L LBL-38130 %2 LBL-38130 %3
Integrated Systems%$
Commercial Building Systems%]
y%0 Conference Paper %B Electrochemical Society Meeting %D 1996 %T Electrochromic Lithium Nickel Oxide Thin Film by Pulsed Laser Deposition %A Shi-Jie Wen %A Klaus von Rottkay %A Michael D. Rubin %X
Thin films of lithium nickel oxide were deposited by pulsed laser deposition (PLD) from targets of pressed LiNiO2 powder with layered structure. The composition, structure and surface air sensitivity of these films were analyzed using a variety of techniques, such as nuclear reaction analysis, Rutherford backscattering spectrometry (RBS), x-ray diffraction, infrared spectroscopy, and atomic force microscopy. Optical properties were measured using a combination of variable angle spectroscopic ellipsometry and spectroradiometry. Crystalline structure, surface morphology and chemical composition of LixNi1-xO thin films depend strongly on deposition oxygen pressure, temperature as well as substrate target distance. The films produced at temperatures lower than 600 °C spontaneously absorb CO2 and H2O at their surface once they are exposed to the air. The films deposited at 600 °C proved to be stable in air over a long period. Even when deposited at room temperature the PLD films are denser and more stable than sputtered films. RBS determined that the best electrochromic films had the stoichiometric composition Li0.5Ni0.5O when deposited at 60 mTorr O2 pressure. Electrochemical tests show that the films exhibit excellent reversibility in the range 1.0 V to 3.4 V versus lithium and long cyclic life stability in a liquid electrolyte half cell. Electrochemical formatting which is used to develop electrochromism in other films and nickel oxide films is not needed for these stoichiometric films. The optical transmission range is almost 70% at 550 nm for 120 nm thick films.%B Electrochemical Society Meeting %C San Antonio, TX %V 96-24 %P 54-63 %8 10/1996 %G eng %L LBNL-39593 %1
Windows and Daylighting Group%2 LBNL-39593 %0 Conference Paper %B ASHRAE Transactions %D 1996 %T Energy Performance Analysis of Prototype Electrochromic Windows %A Robert Sullivan %A Michael D. Rubin %A Stephen E. Selkowitz %X
This paper presents the results of a study investigating the energy performance of three newly developed prototype electrochromic devices. The DOE-2.1E energy simulation program was used to analyze the annual cooling, lighting, and total electric energy use and peak demand as a function of window type and size. We simulated a prototypical commercial office building module located in the cooling-dominated locations of Phoenix, AZ and Miami, FL. Heating energy use was also studied in the heating-dominated location of Madison, WI. Daylight illuminance was used to control electrochromic state-switching. Two types of window systems were analyzed; i.e., the outer pane electrochromic glazing was combined with either a conventional low-E or a spectrally selective inner pane. The properties of the electrochromic glazings are based on measured data of new prototypes developed as part of a cooperative DOE-industry program.
Our results show the largest difference in annual electric energy performance between the different window types occurs in Phoenix and is about 6.5 kWh/m2 floor area (0.60 kWh/ft2) which can represent a cost of about $.52/m2 ($.05/ft2) using electricity costing $.08/kWh. Much larger differences exist when electrochromic windows are compared to conventional glazings in use today. At large window sizes, such energy savings can be as large as 90 kWh/m2 (8.4 kWh/ft2). Specific electrochromic performance varies with window-to-wall area ratio; i.e., at low ratios, one type electrochromic performs best, while at large ratios, another type performs best. In general, an electrochromic glazing combined with a spectrally selective glazings is better than one combined with a low-E glazing; however, at low-window-to-wall area ratios, this situation reverses slightly. There is almost no difference in peak electric demand for the different electrochromic windows analyzed.
In heating-dominated locations, the electrochromic should be maintained in its bleached state during the heating season to take advantage of beneficial solar heat gain which would reduce the amount of required heating. This also means that the electrochromic window with the largest solar heat gain coefficient is best. The largest heating energy performance difference in Madison for the various window types is 43 MJ/m2 floor area (4.0 kBtu/ft2). This represents a cost of about $.26/m2 floor area ($.024/ft2) using gas costing $0.60/therm ($5.69/GJ, $6.00/MBtu). However, a non-switching electrochromic will not provide desired glare control so that a control strategy that minimizes winter heating use may not be routinely desirable in many buildings.%B ASHRAE Transactions %C Boston, MA %V 103, Part 2 %P 149-156 %8 07/1997 %G eng %L LBNL-39905 %1
Windows and Daylighting Group%2 LBNL-39905 %0 Conference Paper %B SPIE International Symposium on Optical Materials Technology for Energy Efficiency & Solar Energy Conversion XV %D 1996 %T The Energy Performance of Electrochromic Windows in Heating-Dominated Geographic Locations %A Robert Sullivan %A Eleanor S. Lee %A Michael D. Rubin %A Stephen E. Selkowitz %X
This paper presents the results of a study investigating the energy performance of electrochromic windows in heating-dominated geographic locations under a variety of state-switching control strategies. We used the DOE-2.1E energy simulation program to analyze the annual heating, cooling and lighting energy use and performance as a function of glazing type, size, and electrochromic control strategy. We simulated a prototypical commercial office building module located in Madison, Wisconsin. Control strategies analyzed were based on daylight illuminance, incident total solar radiation, and space cooling load. Our results show that overall energy performance is best if the electrochromic is left in its clear or bleached state during the heating season, but controlled during the cooling season using daylight illuminance as a control strategy. Even in such heating dominated locations as Madison, there is still a well-defined cooling season when electrochromic switching will be beneficial. However, having the electrochromic remain in its bleached state during the winter season may result in glare and visual comfort problems for occupants much in the same way as conventional glazings.%B SPIE International Symposium on Optical Materials Technology for Energy Efficiency & Solar Energy Conversion XV %C Freiburg, Germany %8 09/1996 %G eng %L LBL-38252 %1
Windows and Daylighting Group%2 LBL-38252 %0 Report %D 1996 %T Guidelines for Sustainable Building Design: Recommendations from the Presidio of San Francisco Energy Efficiency Design Charrette %A Karl A. Brown %A Dale A. Sartor %A Steve E. Greenberg %A Tai Voong %A Doug Lockhart %A Dennis Kincy %A Scott Wentworth %A Thomas Riley %A Doug Chamberlin %A Brian Hines %A James P. Waltz %A Frank W. Mayhew %X
In 1994, the Bay Area Chapter of the Association of Energy Engineers organized a two-day design charrette for energy efficient redevelopment of buildings by the National Park Service (NPS) at the Presidio Army Base. This event brought together engineers, researchers, historical architects, government officials, and students in a participatory environment to apply their experience to creating guidelines for sustainable redesign of Presidio buildings.
The venue for the charette was a representative barracks building located in the Main Post area. Examination of this building allowed development of ideas both for the building and for the remainder of the facilities. The charrette was organized into a committee structure including: steering, measurement and monitoring, modeling, building envelope and historic preservation (architectural), HVAC and controls, lighting, presentation. Prior to the charrette itself, the modeling and measurement/monitoring committee developed substantial baseline data for the other committees. A systems-oriented approach was initiated through interaction between the committees and later through coordination of the committee reports in an ad hoc integration exercise.
The information developed in the charrette, combined with experience gained by the Lawrence Berkeley National Laboratory Applications Team in subsequent actual Presidio design assistance for the NPS, forms the basis for this report. Synergism with historical preservation considerations is emphasized. It is hoped that this document will contribute to the sustainable development of the Presidio and provide an advanced view of facility design which emphasizes optimization, an interdisciplinary integrated systems approach and interaction between phases of design.%8 05/1966 %G eng %1
Applications Team%2 LBNL-38868 %0 Conference Proceedings %B Materials Research Society Symposium N – III-V Nitrides %D 1996 %T Impact of Growth Temperature, Pressure and Strain on the Morphology of GaN Films %A Hiroaki Fujii %A Christian F. Kisielowski %A Joachim Krüger %A Michael S.H. Leung %A Ralf Klockenbrink %A Michael D. Rubin %A Eicke R. Weber %E Joachim Krüger %X
GaN films grown on sapphire at different temperatures are investigated. A Volmer-Weber growth mode is observed at temperatures below 1000K that leads to thin films composed of oriented grains with finite size. Their size is temperature dependent and can actively be influenced by strain. Largest grains are observed in compressed films. It is argued that diffusing Ga ad-atoms dominate the observed effects with an activation energy of 2.3 ± 0.5 eV. Comparably large grain sizes are observed in films grown on off-axes sapphire substrates and on bulk GaN. This assures that the observed size limitation is a consequence of the 3D growth mode and not dependent on the choice of the substrate. In addition, the grain size and the surface roughness of the films depend on the nitrogen partial pressure in the molecular beam epitaxy (MBE) chamber,most likely due to collisions between the reactive species and the background gas molecules. This effect is utilized to grow improved nucleation layers on sapphire.%B Materials Research Society Symposium N – III-V Nitrides %V 449 %P 227 %G eng %1
Windows and Daylighting Group%2 LBNL-39850 %R 10.1557/PROC-449-227 %0 Report %D 1996 %T Optical and Electrochromic Properties of Sol-Gel Deposited Doped Tungsten Oxide Films %A Nilgün Özer %A Carl M Lampert %A Michael D. Rubin %X
The goal of this study is to investigate the effects of doping of tungsten oxide on its electrochromic properties. The work is directed toward the development of neutral coloring tungsten oxide materials with properties superior to undoped tungsten oxide. Two basic types of sol-gel formulations were used for experimentation. Type 1 used a WOCl4 precursor. Type 2 used a proprietary (Donnelly) tungsten complex precursor. The Type 2 precursor was used only for comparison to Type 1. Doping experiments were performed using the Type 1 chemistry. The dopants studied were Co, Cr, Nb, Ti, V and Y. The range of dopant was 1-12 mole %. Improved electrochromic behavior was observed for tungsten oxide films doped with V and Ti.
Analysis of the films included x-ray diffraction, ellipsometry, cyclic voltammetry and spectrophotometry. X-ray diffraction showed that all films heat treated at temperatures below 300°C were amorphous in structure. The refractive indices for undoped films were measured. We found the n, k values of the Type 1 films to be lower than the Type 2 films. The n and k values were n=1.79 and k=2.8x10-3, and n=2.08 and k=3.6x10-3 at 550 nm, for Type 1 and Type 2 films respectively. Both types of tungsten oxide films showed low absorption and high transparency in the visible range. As expected, we found that the film density, and hence the refractive index and extinction coefficient, depended on coating solution chemistry, hydration, and densification procedures. Undoped Type 1 films showed slightly higher lithium diffusion coefficients (DLi), compared to undoped Type 2 films, DLi=1.36x 10-9 cm2 s-1 and 1.31 x 10-9 cm2 s-1, respectively.
We also noted that the properties of the films could be reproduced for any coating chemistry and densification scheme. The electrochemical and optical behavior were determined by using an in-situ cuvette cell with a 1M LiCl04 / propylene carbonate electrolyte. Cyclic voltammetric measurements showed that doped Type 1 films exhibited electrochemical reversibility beyond 1200 cycles without change in charge capacity. A slight lowering of charge capacity was noted for the undoped films after cycling. The charge capacity for the V doped film was 16.9 mC/cm2 compared to undoped film, 9.6 mC/cm2. Spectrophotometry showed that doped films tended to exhibit a higher absorbance in their colored state compared to undoped films. Considerable improvement in the lithium diffusivity was noted for all the doped films. The greatest change was a factor of 20x for vanadium doping. Doping appeared to increase the cyclic durability of all the tungsten films out to 1200 cycles. Color changes by doping were noted for several dopants. The doped films with the best overall properties were about 8% vanadium and titanium tungsten oxide. The optimum concentration lies in the range of 7 to 12 mol%. The electrochromic color was a neutral brownish-blue for vanadium and grayish-blue for titanium doped tungsten oxide.%C Berkeley %8 01/1996 %2 LBID-2163 %0 Journal Article %J Thin Solid Films %D 1996 %T Optical Indices of Electrochromic Tungsten Oxide %A Klaus von Rottkay %A Michael D. Rubin %A Shi-Jie Wen %K Colored state %K Complex refractive index %K electrochromic %K tungsten oxide %X
Tungsten trioxide (WO3) is the most widely used material for the active layer of electrochromic devices. Knowledge of the complex refractive index over the range of coloration states is required for device design. Optical constants of WO3 over the whole solar spectrum were determined as a function of injected charge. Films of WO3 were prepared by electron-beam evaporation, then colored in several steps by reduction with lithium (Li) up to 68 mC cm-2 µm-1 injected charge. Measurements included variable-angle spectroscopic ellipsometry and spectroscopic transmittance and reflectance at normal incidence. Analysis was complicated by the fact that a transparent-conducting layer of indium tin oxide (ITO) was required to perform lithiation. Optical indices of the glass substrate and ITO transparent conductor were determined separately and then fixed in the model. The indices of WO3 could then be extracted from measurements on the complete structure. A parametric dispersion model corresponding to Gaussian broadening of the oscillators was used to represent the dielectric response of WO3.%B Thin Solid Films %V 306 %P 10-16 %8 08/1997 %G eng %N 1 %1
Windows and Daylighting Group%2 LBNL-39687 %& 10 %R 10.1016/S0040-6090(97)00254-X %0 Journal Article %J Solar Energy Materials and Solar Cells %D 1996 %T Optical Indices of Lithiated Electrochromic Oxides %A Michael D. Rubin %A Klaus von Rottkay %A Shi-Jie Wen %A Nilgün Özer %A Jonathan L. Slack %X
Optical indices have been determined for thin films of several electrochromic oxide materials. One of the most important materials in electrochromic devices, WO3, was thoroughly characterized for a range of electrochromic states by sequential injection of Li ions. Another promising material, Li0.5Ni0.5O, was also studied in detail. Less detailed results are presented for three other common lithium-intercalating electrochromic electrode materials: V2O5, LiCoO2, and CeO2-TiO2. The films were grown by sputtering, pulsed laser deposition (PLD) and sol-gel techniques. Measurements were made using a combination of variable-angle spectroscopic ellipsometry and spectroradiometry. The optical constants were then extracted using physical and spectral models appropriate to each material. Optical indices of the underlying transparent conductors, determined in separate studies, were fixed in the models of this work. The optical models frequently agree well with independent physical measurements of film structure, particularly surface roughness by atomic force microscopy. Inhomogeneity due to surface roughness, gradient composition, and phase separation are common in both the transparent conductors and electrochromics, resulting sometimes in particularly complex models for these materials. Complete sets of data are presented over the entire solar spectrum for a range of colored states. This data is suitable for prediction of additional optical properties such as oblique transmittance and design of complete electrochromic devices.%B Solar Energy Materials and Solar Cells %V 54 %P 49-57 %8 07/1998 %G eng %N 1-4 %1
Windows and Daylighting Group%2 LBNL-39410 %& 49 %R 10.1016/S0927-0248(97)00222-5 %0 Conference Paper %B Materials Research Society 1996 Spring Meeting %D 1996 %T Optical Indices of Pyrolitic Tin-Oxide Glass %A Klaus von Rottkay %A Michael D. Rubin %X
SnO2:F is a widely used transparent conductor and commercially available in a multilayer structure as Tech glass. Current applications include photovoltaics, electrochromics and displays. Optical design of these and other applications requires knowledge of the optical constants, in some cases, over the whole solar spectrum. Various optical property measurements were performed including variable angle spectroscopic ellipsometry, and spectral transmittance and reflectance measurements. This material is deposited in several steps and has a fairly complex structure. The measured data were fit to models based on this structure to obtain the optical indices. Atomic force microscopy confirmed the optically modeled surface roughness.%B Materials Research Society 1996 Spring Meeting %C San Francisco, CA %V 426 %8 04/1996 %G eng %L LBL-38586 %1
Windows and Daylighting Group%2 LBL-38586 %0 Conference Paper %B 2nd International Conference on Electrochromics %D 1996 %T Optical Modeling of a Complete Electrochromic Device %A Klaus von Rottkay %A Michael D. Rubin %A John B. Kerr %X
Optical indices have been determined for thin films of all materials needed to model a typical electrochromic device. Two electrochromic materials, tungsten oxide and lithium nickel oxide, are widely used in electrochromic devices. The optical indices of the underlying transparent conductors as well as a polymer electrolyte were also analyzed. The optical data was obtained using a combination of variable-angle spectroscopic ellipsometry and spectroradiometry. The data was then fit to appropriate models of structure and dispersion in order to extract the optical indices of the materials. First, the optical indices of the transparent conductive substrates were obtained and fixed in the model. The best models correspond well to independent physical measurements of film structure, such as atomic-force microscopy and surface profiling. Surface roughness, gradient composition and other types of inhomogeneity are common in both the transparent conductors and electrochromic, resulting in particularly complex models. The polymer has a homogeneous structure, but obtaining optically smooth surfaces was a problem. Complete sets of data were produced over the entire solar spectrum for a range of colored states of the films. Using the data for each layer, a realistic electrochromic device was simulated.%B 2nd International Conference on Electrochromics %C San Diego, CA %8 10/1996 %G eng %L LBNL-39594 %1
Windows and Daylighting Group%2 LBNL-39594 %0 Conference Paper %B 23rd International Conference on the Physics of Semiconductors %D 1996 %T Origin of Strain in GaN Thin Films %A Christian F. Kisielowski %A Joachim Krüger %A Michael S.H. Leung %A Ralf Klockenbrink %A Hiroaki Fujii %A Tadeusz Suski %A Sudhir G. Subramanya %A Joel W. Ager III %A Michael D. Rubin %A Eicke R. Weber %E Joachim Krüger %X
Photoluminescence measurements are used to determine the strain in GaN thin films grown by Molecular Beam Epitaxy. The strain which originates from growth on lattice mismatched substrates and from differences in thermal expansion coefficients is found to be greatly relaxed. Residual strains are shown to depend on the thickness of GaN buffer layers and the III/V flux ration during main layer growth. The results strongly suggest that the residual biaxial strain caused by the post-growth cooling can be modified by the incorporation of point defects during the main layer growth which introduce an additional hydrostatic strain field. The effect allows for strain engineering of GaN crystals.%B 23rd International Conference on the Physics of Semiconductors %C Singapore %V 4 %P 513 %G eng %L LBNL-39853 %1
Windows and Daylighting Group%2 LBNL-39853 %0 Conference Paper %B 1996 ACEEE Summer Study on Energy Efficiency in Buildings %D 1996 %T Policies to reduce heat islands: Magnitudes of benefits and incentives to achieve them %A Arthur H. Rosenfeld %A Joseph J. Romm %A Hashem Akbari %A Melvin Pomerantz %A Haider Taha %K Heat Island %K urban heat island %X
A "Cool Communities" strategy of lighter-colored reroofs and resurfaced pavements, and shade trees, can directly lower annual air conditioning bills in Los Angeles (LA) by about $100 million (M), cool the air in the LA Basin (thereby saving indirectly $70M more in air conditioning), and reduce smog exceedance by about 10%, worth another $360M, for a total savings of about $0.5 billion per year. Trees are most effective if they shade buildings; but they are still very cost effective if they merely cool the air by evapotranspiration. Avoided peak power for air conditioning can be about 1.5GW (more than 15% of LA air conditioning). Extrapolated to the entire US, the authors estimate 20GW avoided and potential annual electricity savings of about $5–10B in 2015. To achieve these savings, they call for ratings and labels for cool materials, buildings` performance standards, utility incentive programs, and an extension of the existing smog-offset trading market (RECLAIM) to include credit for cool surfaces and trees. EPA can include cool materials and trees in its proposed regional "open market smog-offset trading credits".%B 1996 ACEEE Summer Study on Energy Efficiency in Buildings %7 18 %C Asilomar Conference Grounds, Pacific Grove, CA %V 9 %P 177-186 %8 05/1996 %G eng %2 LBL-38679 %0 Conference Paper %B International Symposium on Glass Problems, International Commission on Glass %D 1996 %T Sol-Gel Deposited Electrochromic Films for Electrochromic Smart Window Glass %A Nilgün Özer %A Carl M Lampert %A Michael D. Rubin %X
Electrochrornic windows offer the ability to dynamically change the transmittance of a glazing. With the appropriate sensor and controls, this smart window can be used for energy regulation and glare control for a variety of glazing applications. The most promising are building and automotive applications. This work covers the use of sol-gel deposition processes to make active films for these windows. The sol-gel process offers a low-capital investment for the deposition of these active films. Sol-gel serves as an alternative to more expensive vacuum deposition processes. The sol-gel process utilizes solution coating followed by a hydrolysis and condensation. In this investigation we report on tungsten oxide and nickel oxide films made by the sol-gel process for electrochromic windows. The properties of the sol-gel films compare favorably to those of films made by other techniques. A typical laminated electrochromic window consists of two glass sheets coated with transparent conductors, which are coated with the active films. The two sheets are laminated together with an ionically conductive polymer. The range of visible transmission modulation of the tungsten oxide was 60% and for the nickel oxide was 20%. We used the device configuration of glass/SnO2:F/WO3/polymer/LizNiOxHy/SnO2:F to test the films. The nickel oxide layer had a low level of lithiation and possibly contained a small amount of water. Lithiated oxymethylene-linked poly(ethylene oxide) was used as the laminating polymer. Commercially available Sn02:F/glass (LOF-Tec glass) was used as the transparent conducting glass. We found reasonable device switching characteristics which could be used for devices.%B International Symposium on Glass Problems, International Commission on Glass %C Istanbul, Turkey %8 09/1996 %G eng %1
Windows and Daylighting Group%2 LBNL-39852 %0 Journal Article %J Physical Review B %D 1996 %T Strain Related Phenomena in GaN Thin Films %A Christian F. Kisielowski %A Joachim Krüger %A Sergei Ruvimov %A Tadeusz Suski %A Joel W. Ager III %A Erin C. Jones %A Zuzanna Liliental-Weber %A Michael D. Rubin %A Eicke R. Weber %A Michael D. Bremser %A Robert F. Davis %E Joachim Krüger %X
Photoluminescence (PL), Raman spectroscopy, and x-ray diffraction are employed to demonstrate the co-existence of a biaxial and a hydrostatic strain that can be present in GaN thin films. The biaxial strain originates from growth on lattice-mismatched substrates and from post-growth cooling. An additional hydrostatic strain is shown to be introduced by the presence of point defects. A consistent description of the experimental results is derived within the limits of the linear and isotropic elastic theory using a Poisson ratio nu =0.23+/-0.06 and a bulk modulus B=200+/-20 GPa. These isotropic elastic constants help to judge the validity of published anisotropic elastic constants that vary greatly. Calibration constants for strain-induced shifts of the near-band-edge PL lines with respect to the E2 Raman mode are given for strain-free, biaxially strained, and hydrostatically contracted or expanded thin films. They allow us to extract differences between hydrostatic and biaxial stress components if present. In particular, we determine that a biaxial stress of one GPa would shift the near-band-edge PL lines by 27+/-2 meV and the E2 Raman mode by 4.2+/-0.3 cm-1 by use of the listed isotropic elastic constants. It is expected from the analyses that stoichiometric variations in the GaN thin films together with the design of specific buffer layers can be utilized to strain engineer the material to an extent that greatly exceeds the possibilities known from other semiconductor systems because of the largely different covalent radii of the Ga and the N atom.%B Physical Review B %V 54 %P 17745-17753 %8 12/1996 %G eng %N 24 %1
Windows and Daylighting Group%2 LBNL-39079 %& 17745 %R 10.1103/PhysRevB.54.17745 %0 Conference Paper %B Proceedings of the 1996 ACEEE Summer Study on Energy Efficiency in Buildings, August 25-31, 1996 %D 1996 %T User Satisfaction with Innovative Cooling Retrofits in Sacramento Public Housing %A Richard C. Diamond %A Jim Remus %A Bruce Vincent %X
How do tenants of public housing respond to retrofits to improve their comfort and energy use during the cooling season? In contrast to retrofits to improve heating or lighting, cooling retrofits have been little studied, despite extensive programs by utilities and housing authorities to reduce this end use. A local utility and a housing authority have been retrofitting their buildings with evaporative coolers, ground-source heat pumps and other cooling measures. As part of an overall evaluation of the project we have conducted interviews with the residents, building managers and project staff to determine satisfaction with the performance of the systems. The initial evaluation revealed glaring defects in the design and installation of the systems, and not surprisingly, there was great dissatisfaction by the tenants and staff with their performance. Subsequent interventions and improvements to the equipment solved the technical problems, but tenant satisfaction was mixed. Further surveys revealed misunderstandings by the tenants on the nature of the evaporative coolers, their control and operation—often due to poor thermostat design—and expectations for comfort and familiarity with the technology. A significant finding from the study has been that despite the technical potential for these retrofit measures, the improper implementation of the systems, maintenance requirements and user behavior can all greatly impact the projected energy savings.%B Proceedings of the 1996 ACEEE Summer Study on Energy Efficiency in Buildings, August 25-31, 1996 %I American Council for an Energy Efficient Economy, Washington, DC %C Pacific Grove, CA %V 8 %P 21 %8 08/1996 %G eng %1
1.1%& Chapter %0 Conference Paper %B SPIE Optical Materials Technology for Energy Efficiency and Solar Energy Conversion XV %D 1996 %T Visual Quality Assessment of Electrochromic and Conventional Glazings %A Martin Moeck %A Eleanor S. Lee %A Michael D. Rubin %A Robert Sullivan %A Stephen E. Selkowitz %X
Variable transmission, switchable electrochromic glazings are compared to conventional static glazings using computer simulations to assess the daylighting quality of a commercial office environment where paper and computer tasks are performed. RADIANCE simulations were made for a west-facing commercial office space under clear and overcast sky conditions. This visualization tool was used to model different glazing types, to com-pute luminance and illuminance levels, and to generate a parametric set of photorealistic im-ages of typical interior views at various times of the day and year. Privacy and visual dis-play terminal (VDT) visibility is explored. Electrochromic glazings result in a more consis-tent glare-free daylit environment compared to their static counterparts. However, if the glazing is controlled to minimize glare or to maintain low interior daylight levels for critical visual tasks (e.g., VDT), occupants may object to the diminished quality of the outdoor view due to its low transmission (Tv=0.08) during those hours. RADIANCE proved to be a very powerful tool to better understand some of the design tradeoffs of this emerging glazing technology. Our ability to draw specific conclusions about the relative value of dif-ferent technologies or control strategies is limited by the lack of agreed upon criteria or standards for lighting quality and visibility.%B SPIE Optical Materials Technology for Energy Efficiency and Solar Energy Conversion XV %C Freiburg, Germany %8 09/1996 %G eng %1
Windows and Daylighting Group%2 LBNL-39471 %0 Journal Article %D 1996 %T You Won't Find These Leaks with a Blower Door: The Latest in "Leaking Electricity" in Homes %A Leo I. Rainer %A Steve E. Greenberg %A Alan K. Meier %2 LBNL-39545 %0 Conference Paper %B Thermal Performance of the Exterior Envelopes of Buildings VI Conference %D 1995 %T Advances in Thermal and Optical Simulations of Fenestration Systems: The Development of WINDOW 5 %A Elizabeth U. Finlayson %A Dariush K. Arasteh %A Michael D. Rubin %A John Sadlier %A Robert Sullivan %A Charlie Huizenga %A Dragan C. Curcija %A Mark Beall %X
WINDOW is a personal-computer-based computer program used by manufacturers, researchers, and consumers to evaluate the thermal performance properties (U-factors, solar heat gain and shading coefficients, and visible transmittances) of complete windows and other fenestration systems. While WINDOW is used by thousands of users in the United States and internationally and is at the foundation of the National Fenestration Rating Council's U-factor and solar heat gain property procedures, improvements to the program are still necessary for it to meet user needs. Version 5, intended for release in late 1995, is being developed to meet these needs for increased accuracy, a flexible and state-of-the-art user interface, and the capabilities to handle more product types.
WINDOW 5 includes the capabilities to define and model the thermal performance of frames/dividers and their associated edge effects. Currently, such an analysis must be performed outside of WINDOW and requires simplifications to be made to frame profiles or is based on the use of generic frame and edge correlations. WINDOW's two-dimensional thermal model is composed of four sections: a graphical input, automatic grid generation, an finite-element analysis (FEA) solution, and the display of results. In the graphical input section, users are able to directly import a computer-aided design (CAD) drawing or a scanned image of a window profile, replicate its exact geometry, and assign material types and boundary conditions. The automatic grid generation is transparent to the user, with the exception of the requirement that complex shapes (i.e., an aluminum extrusion) be broken down into simpler polyshapes. Inclusion of an automatic grid generation makes detailed "true geometry" frame-and-edge heat-transfer analysis accessible to users without extensive knowledge of numerical methods of heat-transfer analysis. After the cross section is meshed it is sent to the FEA engine for solution and the results are returned. A postprocessor allows for the visual display of temperature and heat flux plots. Note that while this two-dimensional heat-transfer tool is being developed specifically for fenestration products, it also can be used to analyze other building envelope components.
WINDOW 5 also will include a built-in version of a national laboratory's program that allows the user to estimate the orientation-dependent annual energy impacts of a given window in a typical residence in various U.S. climates. This program is based on regressions to a database of DOE2.1 runs. Future versions will include a similar feature for commercial buildings.
Other technical additions include an improved angular/ spectral model for coated and uncoated glazings, the ability to analyze the optical properties of nonhomogeneous layers, and the ability to model the effects of laminated glazing layers. A door module permits the user to compute the total U-factors of exterior doors based on component U-factors calculated using the two-dimensional FEA module.%B Thermal Performance of the Exterior Envelopes of Buildings VI Conference %C Clearwater Beach, FL %8 12/1995 %G eng %1
Windows and Daylighting Group%2 LBL-37283 %0 Conference Paper %B 6th Eurographics Workshop on Rendering %D 1995 %T Comparing Real and Synthetic Images: Some Ideas about Metrics %A Holly Rushmeier %A Gregory J. Ward %A Christine Paitko %A Phil Sanders %A Bert W. Rust %X
This paper explores numerical techniques for comparing real and synthetic luminance images. We introduce components of a perceptually based metric using ideas from the image compression literature. We apply a series of metrics to a set of real and synthetic images, and discuss their performance. FinaIly, we conclude with suggestions for future work in formulating image metrics and incorporating them into new image synthesis methods.%B 6th Eurographics Workshop on Rendering %C Dublin, Ireland %8 06/1995 %G eng %L LBL-37859 %1
Lighting Systems Group%2 LBL-37859 %0 Journal Article %J ASTM Standardization News %D 1995 %T Cool construction materials offer energy savings and help reduce smog %A Hashem Akbari %A Arthur H. Rosenfeld %A Haider Taha %K Cool Pavements %K Heat Island %B ASTM Standardization News %V 23 %P 32-37 %G eng %U http://www.docstoc.com/docs/17477497/Cool-Construction-Materials-Offer-Energy-Savings-and-Help-Reduce %0 Conference Paper %B International Conference on Metallurgical Coatings and Thin Films, April 24-28, 1995 %D 1995 %T Formation of Metal Oxides by Cathodic Arc Deposition %A Simone Anders %A André Anders %A Michael D. Rubin %A Zhien Wang %A Sebastien Raoux %A Fanping Kong %A Ian G. Brown %K Cathodic arc deposition %K Oxide formation %X
Metal oxide thin films are of interest for a number of applications. Cathodic arc deposition, which is an established and industrially applied technique for the formation of nitrides (e.g. TIN), can also be used for metal oxide thin film formation. A cathodic arc plasma source with the desired cathode material is operated in an oxygen atmosphere of appropriate pressure, and metal oxides of various stoichiometric composition can be formed on different substrates. We report here on a series of experiments on metal oxide formation by cathodic arc deposition for different applications. Black copper oxide has been deposited on accelerator components to increase the radiative heat transfer between the parts. Various metal oxides such as tungsten oxide, niobium oxide, nickel oxide and vanadium oxide have been deposited on ITO glass to form electrochromic films for window applications. Tantalum oxide films are of interest for replacing polymer electrolytes. Optical waveguide structures can be formed by refractive index variation using oxide multilayers. We have synthesized multilayers of Al2O3/Y2O3/Al2O3/Si as possible basic structures for passive optoelectronic integrated circuits, and Al2-xErxO3 thin films with a variable Er concentration which is a potential component layer for the production of active optoelectronic integrated devices such as amplifiers or lasers at a wavelength of 1.53 pm. Aluminum and chromium oxide films have been deposited on a number of substrates to impart improved corrosion resistance at high temperature. Titanium sub-oxides which are electrically conductive and corrosion resistant and stable in a number of aggressive environments have been deposited on various substrates. These sub-oxides are of great interest for use in electrochemical cells. Common features of all these depositions are the high deposition rate typical for cathodic arc deposition, the good adhesion of the films due to the high metal ion energy, and the advantage of an environmentally clean method in comparison to wet-chemical oxide formation techniques.%B International Conference on Metallurgical Coatings and Thin Films, April 24-28, 1995 %C San Diego, CA %8 04/1995 %G eng %U http://dx.doi.org/10.1016/0257-8972(95)02508-1 %1
Windows and Daylighting Group%2 LBL-36166 %0 Journal Article %J Journal of Electronic Materials %D 1995 %T The Influence of Nitrogen Ion Energy on the Quality of GaN Films Grown with Molecular Beam Epitaxy %A T.C. Fu %A Nathan Newman %A Erin C. Jones %A James S. Chan %A Xiaohong Liu %A Michael D. Rubin %A Nathan W. Cheung %A Eicke R. Weber %K Activated nitrogen %K GaN %K molecular beam epitaxy (MBE) %K nitrogen ion energy %X
Since the growth of GaN using molecular beam epitaxy (MBE) occurs under metastable growth conditions, activated nitrogen is required to drive the forward synthesis reaction. In the process of exciting the nitrogen using a plasma or ion-beam source, species with large kinetic energies are generated. Impingement on the growth surface by these species can result in subsurface damage to the growing film, as well as an enhancement of the reverse decomposition reaction rate. In this study, we investigate the effect of the kinetic energy of the impinging nitrogen ions during growth on the resulting optical and structural properties of GaN films. Strong band-edge photoluminescence and cathodoluminescence are found when a kinetic energy of ~10 eV are used, while luminescence is not detectable when the kinetic energies exceeds 18 eV. Also, we find that the use of conductive SiC substrates results in more homogeneous luminescence than the use of insulating sapphire substrates. This is attributed to sample surface charging in the case of sapphire substrates and subsequent variation in the incident ion flux and kinetic energy across the growth surface.This study clearly shows that the quality of GaN films grown by MBE are presently limited by damage from the impingement of high energy species on the growth surface.%B Journal of Electronic Materials %V 24 %P 249-255 %8 04/1995 %G eng %N 4 %1
Windows and Daylighting Group%2 LBL-37223 %& 249 %R 10.1007/BF02659683 %0 Conference Paper %B Illuminating Engineering Society of North America %D 1995 %T An In-Situ Photometric and Energy Analysis of a Sulfur Lamp Lighting System %A Douglas G. Crawford %A Carl T. Gould %A Michael Packer %A Francis M. Rubinstein %A Michael J. Siminovitch %X
This paper describes the results of a photometric and energy analysis that was conducted on a new light guide and sulfur lamp system recently installed at the U.S. Department of Energys Forrestal Building. This novel system couples two high lumen output, high efficiency sulfur lamps to a single 73 m (240 ft.) hollow light guide lined with a reflective prismatic film. The system lights a large roadway and plaza area that lies beneath a section of the building. It has been designed to completely replace the grid of 280 mercury vapor lamps formerly used to light the space. This paper details the results of a field study that characterizes the significant energy savings and increased illumination levels that have been achieved. Comparisons to modeled HID lighting scenarios are also included.%B Illuminating Engineering Society of North America %C New York, NY %8 08/1995 %G eng %1
Lighting Systems Group%2 LBL-37006 %0 Journal Article %J Energy and Buildings %D 1995 %T Mitigation of urban heat islands: materials, utility programs, updates %A Arthur H. Rosenfeld %A Hashem Akbari %A Sarah E. Bretz %A Beth L. Fishman %A Dan M. Kurn %A David J. Sailor %A Haider Taha %K Air-conditioning electricity savings %K Cool roads %K cool roofs %K Smog mitigation %K Urban heat islands %K Utility programs %X
Elevated temperatures in urban "heat islands" increase cooling energy use and accelerate the formation of urban smog. Urban shade trees and light-colored surfaces can offset or reverse the heat island and conserve energy. Implementation of heat island mitigation measures is now a prominent part of President Clinton's Climate Change Action Plan to control the emissions of greenhouse gases, necessitating a better understanding of the quantitative benefits of these control measures. We present recent measurements of the air-conditioning savings for houses in Sacramento and Florida, and air temperature measurements at White Sands National Monument, New Mexico. We also discuss the results of meteorological and smog simulations for the Los Angeles Basin. The albedo of a city may be increased gradually if high-albedo surfaces are chosen to replace darker materials during routine maintenance of roofs and roads. Such high-albedo surfaces may last longer than their conventional dark counterparts. Utility-sponsored incentive programs, product labeling, and standards could promote the use of high-albedo materials for buildings and roads, and several paint manufacturers have expressed interest in participating in a "cool surfaces" labeling program. We examine the spectral reflectance of various white coatings and building materials that might be labeled in such a program.%B Energy and Buildings %V 22 %P 255-265 %8 08/1995 %G eng %N 3 %R 10.1016/0378-7788(95)00927-P %0 Conference Proceedings %B Building Simulation '95 %D 1995 %T A Model of a Displacement Ventilation/Chilled Ceiling Cooling System Suitable for Annual Energy Simulation %A Simon J. Rees %A Philip Haves %B Building Simulation '95 %C Madison, WI %8 08/1995 %G eng %0 Conference Proceedings %B Tsinghua HVAC-95 %D 1995 %T Modelling and Simulation of Low Energy Cooling Systems %A Philip Haves %A Simon J. Rees %A Harrington, L. %B Tsinghua HVAC-95 %C Bejing, China %8 09/1995 %G eng %0 Journal Article %J Solar Energy Materials and Solar Cells %D 1995 %T Optical and Electrochemical Characteristics of Niobium Oxide Films Prepared by Sol-Gel Process and Magnetron Sputtering: A Comparison %A Nilgün Özer %A Carl M Lampert %A Michael D. Rubin %K D.C. magnetron sputtering %K electrochromism %K Niobia %K optical properties %K sol-gel deposition %X
Electrochromic niobia (Nb205) coatings were prepared by the sot-gel spin-coating and d.c. magnetron sputtering techniques. Parameters were investigated for the process fabrication of sol-gel spin coated Nb205 films exhibiting high coloration efficiency comparable with that d.c. magnetron sputtered niobia films. X-ray diffraction studies (XRD) showed that the sot-gel deposited and magnetron sputtered films heat treated at temperatures below 450°C, were amorphous, whereas those heat treated at higher temperatures were slightly crystalline. X-ray photoelectron spectroscopy (XPS) studies showed that the stoichiometry of the films was Nb205. The refractive index and electrochromic coloration were found to depend on the preparation technique. Both films showed low absorption and high transparency in the visible range. We found that the n, k values of the sot-gel deposited films to be lower than for the sputtered films. The n and k values were n = 1.82 and k = 3 × 10−3, and n = 2.28 and k = 4 × 10−3 at 530 urn for sot-gel deposited and sputtered films, respectively. The electrochemical behavior and structural changes were investigated in 1 M LiC104/propylene carbonate solution. Using the electrochemical measurements and X-ray photoelectron spectroscopy, the probable electrode reaction with the lithiation and delithiation is Nb2O5 + x Li+ + x e− ↔ LixNb205. Cyclic voltametric (CV) measurements showed that both Nb205 films exhibits electrochemical reversibility beyond 1200 cycles without change in performance. "In situ" optical measurement revealed that those films exhibit an electrochromic effect in the spectral range 300 < λ < 2100 nm but remain unchanged in the infrared spectral range. The change in visible transmittance was 40% for 250 nm thick electrodes. Spectroelectrochemical measurements showed that spin coated films were essentially electrochemically equivalent to those prepared by d.c. magnetron sputter deposition.%B Solar Energy Materials and Solar Cells %V 40 %P 285-296 %8 08/1996 %G eng %N 4 %1
Windows and Daylighting Group%2 LBNL-39007 %& 285 %R 10.1016/0927-0248(95)00147-6 %0 Conference Paper %B Material Research Society Symposium %D 1995 %T Optical Indices of the Tin-doped Indium Oxide and Tungsten Oxide Electrochromic Coatings %A Klaus von Rottkay %A Michael D. Rubin %A Nilgün Özer %X
Thin films of tin-doped indium oxide are widely used for transparent conductors. One application of In2O3:Sn (ITO) is transparent contacts for electrochromic electrodes. Optical design of electrochromic devices requires knowledge of the optical constants for each layer from the near ultraviolet and visible to the mid infrared. Determination of the optical constants of the electrochromic layer cannot be made in isolation; a complete device or at least a half-cell including a layer of ITO is required to change the optical state of the electrochromic material. Measurements on ITO were made using variable-angle spectral ellipsometry, and spectral transmittance and reflectance. A series of structural models were fit to this data. The problem is complicated because of inhomogeneity in the films, variability in the manufacturing process, and sensitivity to environmental conditions. The spectral dependency was modeled by a single Lorentz oscillator and a Drude free-electron component. This data was then used as the basis for a model to extract the optical constants for a tungsten oxide electrochromic film.%B Material Research Society Symposium %V 403 %P 551-556 %G eng %L LBL-38042 %1
Windows and Daylighting Group%2 LBL-38042 %0 Conference Paper %B 3rd European Conference on Energy-Efficiency Lighting, Right Light Three %D 1995 %T A Photometric and Energy Assessment of a Novel Lighting System %A Douglas G. Crawford %A Carl T. Gould %A Michael Packer %A Francis M. Rubinstein %A Michael J. Siminovitch %X
This paper describes the results of a photometric and energy analysis that was conducted on a new light guide and sulfur lamp system recently installed at both the U.S. Department of Energy's Forrestal building and the Smithsonian Institutions National Air and Space Museum. This system couples high lumen output, high efficiency sulfur lamps to hollow light guides lines with a reflective prismatic film. At the Forrestal building the system lights a large roadway and plaza area that lies beneath a section of the building. It has been designed to completely replace the grid of 280 mercury vapor lamps formerly used to illuminate the space. At the National Air and Space Museum a similar system illuminates Gallery 114, which houses the large rocket displays from the U.S. Space program. This paper outlines the unique operational and design characteristics of this highly efficient distribution system and details the results of field studies that characterize the significant energy savings and increased illumination levels that have been achieved. The projected savings in maintenance costs, due to longer lamp life and a reduction of the total number of lamps, is also presented.%B 3rd European Conference on Energy-Efficiency Lighting, Right Light Three %C Newcastle Upon Tyne, England %8 06/1995 %G eng %L LBL-37012 %1
Lighting Systems Group%2 LBL-37012 %0 Conference Paper %B Window Innovations 95 %D 1995 %T Recent Technical Improvements to the WINDOW Computer Program %A Dariush K. Arasteh %A Elizabeth U. Finlayson %A Michael D. Rubin %A John Sadlier %X
The WINDOW series of computer programs has been used since 1985 to model the thermal and optical properties of windows. Each succeeding version of WINDOW has brought its user base new technical capabilities, improvements to the user interface, and greater accuracy. Technical improvements to the current version, which will be released as version 5, are at first being released as stand-alone programs. This paper summarizes the capabilities and algorithms of two of these programs, THERM and LAMINATE. A third stand alone program, RESFEN, which calculates the annual energy effects of specific windows in a typical house throughout the US, will also be incorporated into WINDOW 5; because this program is already in use and documented, it is not discussed in this paper. THERM allows the user to evaluate two dimensional (2-D) heat transfer effects through the solid elements of a window while LAMINATE determines the optical properties of an individual glazing layer with an applied film. Both of these programs are undergoing final development at the time of this writing and will be released as separate programs before they are incorporated into WINDOW 5.%B Window Innovations 95 %C Toronto, Canada %8 06/1995 %G eng %L LBNL-41680 %1
Windows and Daylighting Group%2 LBNL-41680 %0 Conference Paper %B Thermal Performance of the Exterior Envelopes of Buildings VI Conference Proceedings %D 1995 %T Reducing Residential Cooling Requirements Through the Use of Electrochromic Windows %A Robert Sullivan %A Michael D. Rubin %A Stephen E. Selkowitz %X
This paper presents the results of a study investigating the energy performance of electrochromic windows in a prototypical residential building under a variety of state switching control strategies. We used the DOE-2.1E energy simulation program to analyze the annual cooling energy and peak demand as a function of glazing type, size, and electrochromic control strategy. A single-story ranch-style home located in the cooling-dominated locations of Miami, FL and Phoenix, AZ was simulated. Electrochromic control strategies analyzed were based on incident total solar radiation, space cooling load, and outside air temperature. Our results show that an electrochromic material with a high reflectance in the colored state provides the best performance for all control strategies. On the other hand, electrochromic switching using space cooling load provides the best performance for all the electrochrornic materials. The performance of the incident total solar radiation control strategy varies as a function of the values of solar radiation which trigger the bleached and colored states of the electrochromic (setpoint range); i.e., required cooling decreases as the setpoint range decreases; also, performance differences among electrochromics increases. The setpoint range of outside air temperature control of electrochromics must relate to the ambient weather conditions prevalent in a particular location. If the setpoint range is too large, electrochromic cooling performance is very poor. Electrochromics compare favorably to conventional low-E clear glazings that have high solar heat gain coefficients that are used with overhangs. However, low-E tinted glazings with low solar heat gain coefficients can outperform certain electrochromics. Overhangs should be considered as a design option for electrochromics whose state properties do not change significantly between bleached and colored states.%B Thermal Performance of the Exterior Envelopes of Buildings VI Conference Proceedings %C Clearwater Beach, FL %8 12/1995 %G eng %L LBL-37211 %1
Windows and Daylighting Group%2 LBL-37211 %0 Report %D 1995 %T Residential Sector End-use Forecasting with EPRI-REEPS 2.1: Summary Input Assumptions and Results %A Jonathan G. Koomey %A Richard E. Brown %A R. Cooper Richey %A Francis X Johnson %A Alan H. Sanstad %A Leslie J. Shown %K Enduse %K Energy End-Use Forecasting %K EUF %X
This paper describes current and projected future energy use by end-use and fuel for the U.S. residential sector, and assesses which end-uses are growing most rapidly over time. The inputs to this forecast are based on a multi-year data compilation effort funded by the U.S. Department of Energy. We use the Electric Power Research Institute's (EPRI's) REEPS model, as reconfigured to reflect the latest end-use technology data. Residential primary energy use is expected to grow 0.3% per year between 1995 and 2010, while electricity demand is projected to grow at about 0.7% per year over this period. The number of households is expected to grow at about 0.8% per year, which implies that the overall primary energy intensity per household of the residential sector is declining, and the electricity intensity per household is remaining roughly constant over the forecast period. These relatively low growth rates are dependent on the assumed growth rate for miscellaneous electricity, which is the single largest contributor to demand growth in many recent forecasts.%I Lawrence Berkeley Laboratory %8 12/1995 %@ LBL-34044, UC-1600 %G eng %2 LBL-34044 %0 Journal Article %J Applied Physics Letters %D 1995 %T Thermal Annealing Characteristics of Si and Mg-implanted GaN Thin Films %A James S. Chan %A Nathan W. Cheung %A Lawrence F. Schloss %A Erin C. Jones %A William S. Wong %A Nathan Newman %A Xiaohong Liu %A Eicke R. Weber %A A. Gassman %A Michael D. Rubin %K annealing %K crystal doping %K defect states %K electrical properties %K gallium nitrides %K ion implantation %K magnesium additions %K microstructure %K silicon additions %X
In this letter, we report the results of ion implantation of GaN using 28Si and 23Mg species. Structural and electrical characterizations of the GaN thin films after thermal annealing show that native defects in the GaN films dominate over implant doping effects. The formation energies of the annealing induced defects are estimated to range from 1.4 to 3.6 eV. A 30 keV10^14 cm-2 Mg implant results in the decrease of the free-carrier concentration by three orders of magnitude compared to unimplanted GaN up to an annealing temperature of 690 °C. Furthermore, we have observed the correlation between these annealing-induced defects to both improved optical and electrical properties.%B Applied Physics Letters %V 68 %P 2702-2704 %8 03/1996 %G eng %N 19 %1
Windows and Daylighting Group%2 LBL-37372 %& 2702 %R 10.1063/1.116314 %0 Report %D 1994 %T Buildings Sector Demand-Side Efficiency Technology Summaries %A Jonathan G. Koomey %A Francis X Johnson %A Jennifer E. Schuman %A Ellen M. Franconi %A Steve E. Greenberg %A James D. Lutz %A Brent T. Griffith %A Dariush K. Arasteh %A Celina S. Atkinson %A Kristin E. Heinemeier %A Yu Joe Huang %A Lynn K. Price %A Gregory J. Rosenquist %A Francis M. Rubinstein %A Stephen E. Selkowitz %A Haider Taha %A Isaac Turiel %K Enduse %K Energy End-Use Forecasting %K EUF %X
This report provides descriptions of the following energy efficiency technologies: energy management systems; electronic fluorescent ballasts; compact fluorescent lamps; lighting controls; room air conditioners; high albedo materials, coatings and paints; solar domestic water heaters; heat pump water heaters; energy-efficient motors; adjustable-speed drives; energy-efficient refrigerators; daylight control glazing; insulating glazing; solar control glazing; switchable glazing; tree planting; and advanced insulation. For each technology, the report provides a description of performance characteristics, consumer utility, development status, technology standards, equipment cost, installation, maintenance, conservation programs, and environmental impacts.%I Lawrence Berkeley Laboratory (Prepared for the Technology Characterization Database of the Intergovernmental Panel on Climate Change) %8 03/1994 %G eng %2 LBL-33887 %0 Conference Paper %B ACEEE 1994 Summer Study on Energy Efficiency in Buildings %D 1994 %T A Comprehensive Approach to Integrated Envelope and Lighting Systems for New Commercial Buildings %A Eleanor S. Lee %A Stephen E. Selkowitz %A Francis M. Rubinstein %A Joseph H. Klems %A Liliana O. Beltran %A Dennis L. DiBartolomeo %X
We define a comprehensive approach to integrated envelope and lighting systems design as one that balances energy efficiency with anequal regard to the resultant environmental quality. By integrating envelope components (glazing, shading, and daylighting), lighting components (fixtures and controls) and building HVAC/ energy management control systems, we create building systems that have the potential to achieve significant decreases in electricity consumption and peak demand while satisfying occupant physiological and psychological concerns.
This paper presents results on the development, implementation, and demonstration of two specific integrated envelope and lighting systems:
The energy performance of the systems was estimated using the DOE-2 building energy simulation program. Field tests with reduced scale models were conducted to determine daylighting and thermal performance in real time under actual weather conditions. Demonstrations of these integrated systems are being planned or are in progress in collaboration with utility programs to resolve real-world implementation issues under complex site, building, and cost constraints. Results indicate that integrated systems offer solutions that not only achieve significant peak demand reductions but also realize consistent energy savings with added occupant comfort and satisfaction.%B ACEEE 1994 Summer Study on Energy Efficiency in Buildings %C Pacific Grove, CA %8 09/1994 %G eng %L LBL-35732 %1
Commercial Building Systems Group%2 LBL-35732 %0 Conference Proceedings %B 1994 ACSA Technology Conference, %D 1994 %T Design for Photovoltaics: A Curriculum Development Project %A John S. Reynolds %A Robert B. Peña %A Richard C. Diamond %A Jeffrey Cook %A Dimitri Procos %B 1994 ACSA Technology Conference, %S Proceedings of the 1994 ACSA Technology Conference %I ACSA %C Ann Arbor, Michigan %8 01/1994 %G eng %0 Conference Paper %B Solar '94: Golden Opportunities for Solar Prosperity %D 1994 %T Developing Integrated Envelope and Lighting Systems for Commercial Buildings %A Eleanor S. Lee %A Stephen E. Selkowitz %A Francis M. Rubinstein %A Joseph H. Klems %A Liliana O. Beltran %A Dennis L. DiBartolomeo %A Robert Sullivan %X
Integrated envelope and lighting systems achieve significant energy, peak demand, and cost savings over typical component-by-component design practice by leveraging the interactive energy balance between electric lighting energy use and cooling due to lighting and solar radiation. We discuss how these savings can be achieved using conventional glazing and lighting components by taking an integrated systems design approach. We describe integrated dynamic envelope and lighting systems, currently under development, that actively achieve this energy balance through the use of intelligent control systems. We show how prototypical daylighting systems can be used to increase the efficacy and distribution of daylight throughout the space for the same or less glazing area as a typical window, while achieving greater energy savings with increased visual comfort. Energy performance simulations and field tests conducted to date illustrate significant energy savings, peak demand reductions, and potential practical implementation of these proposed systems.%B Solar '94: Golden Opportunities for Solar Prosperity %I American Solar Energy Society, Inc. %C San Jose, CA %8 03/1994 %G eng %L LBL-35412 %2 LBL-35412 %3
June 25-30, 1994%#
Integrated Systems%$
Commercial Building Systems%]
y%0 Conference Paper %B SPIE International Symposium on Optical Materials Technology for Energy Efficiency and Solar Energy Conversion XIII, April 18-22, 1994 %D 1994 %T Effect of Switching Control Strategies on the Energy Performance of Electrochromic Windows %A Robert Sullivan %A Eleanor S. Lee %A Konstantinos M. Papamichael %A Michael D. Rubin %A Stephen E. Selkowitz %X
This paper presents the results of a study investigating the energy performance of electrochromic windows under a variety of state-switching control strategies. We used the DOE-2.1E energy simulation program to analyze the annual cooling, lighting, and total electricity use and peak demand as a function of glazing type, size, and electrochromic control strategy. We simulated a prototypical commercial office building module located in the cooling-dominated location of Blythe, California. Control strategies analyzed were based on daylight illuminance, incident total solar radiation, and space cooling load. Our results show that when a daylighting strategy is used to reduce electric lighting requirements, control algorithms based on daylight illuminance results in the best overall annual energy performance. If daylighting is not an design option, controls based on space cooling load yield the best performance through solar heat gain reduction. The performance of incident total solar radiation control strategies varies as a function of the switching setpoints; for small to moderate window sizes which result in small to moderate solar gains, a large setpoint-range was best since it provides increased illuminance for daylighting without much cooling penalty; for larger window sizes, which provide adequate daylight, a smaller setpoint-range was best to reduce unwanted solar heat gains and the consequential increased cooling requirement. Of particular importance is the fact that reduction in peak electric demand was found to be independent of the type of control strategy used for electrochromic switching. This is because the electrochromics are generally in their most colored state under peak conditions, and the mechanism used for achieving such a state is not important.%B SPIE International Symposium on Optical Materials Technology for Energy Efficiency and Solar Energy Conversion XIII, April 18-22, 1994 %C Freiburg, Germany %8 04/1994 %G eng %1
Windows and Daylighting Group%2 LBNL-35453 %0 Conference Paper %B SIGGRAPH 94 %D 1994 %T Energy Preserving Non-Linear Filters %A Holly Rushmeier %A Gregory J. Ward %X
Monte Carlo techniques for image synthesis are simple and powerful, but they are prone to noise from inadequate sampling. This paper describes a class of non-linear filters that remove sampling noise in synthetic images without removing salient features. This is achieved by spreading real input sample values into the output image via variable-width filter kernels, rather than gathering samples into each output pixel via a constant-width kernel. The technique is non-linear because kernel widths are based on sample magnitudes, and this local redistribution of values cannot generally be mapped to a linear function. Nevertheless, the technique preserves energy because the kernels are normalized, and all input samples have the same average influence on the output. To demonstrate its effectiveness, the new filtering method is applied to two rendering techniques. The first is a Monte Carlo path tracing technique with the conflicting goals of keeping pixel variance below a specified limit and finishing in a finite amount of time; this application shows how the filter may be used to clean up areas where it is not practical to sample adequately. The second is a hybrid deterministic and Monte Carlo ray-tracing program; this application shows how the filter can be effective even when the pixel variance is not known.%B SIGGRAPH 94 %C Orlando, FL %8 07/1994 %G eng %L LBL-37857 %1
Lighting Systems Group%2 LBL-37857 %0 Conference Paper %D 1994 %T Fundamental Materials-Issues Involved in the Growth of GaN by Molecular Beam Epitaxy %A Nathan Newman %A T.C. Fu %A Z. Liu %A Zuzanna Liliental-Weber %A Michael D. Rubin %A James S. Chan %A Erin C. Jones %A Jennifer T. Ross %A Ian M. Tidswell %A Kin Man Yu %A Nathan W. Cheung %A Eicke R. Weber %X
Gallium nitride is one of the most promising materials for ultraviolet and blue light-emitting diodes and lasers. Both Molecular Beam Epitaxy (MBE) and Metal-Organic Chemical Vapor Deposition (MOCVD) have recently made strong progress in fabricating high-quality epitaxial GaN thin films. In this paper, we review materials-related issues involved in MBE growth. We show that a strong understanding of the unique meta-stable growth process allows us to correctly predict the optimum conditions for epitaxial GaN growth. The resulting structural, electronic and optical properties of the GaN films are described in detail.%G eng %L LBL-37296 %2 LBL-37296 %0 Conference Paper %B Thermal Performance of the Exterior Envelopes of Buildings V Conference %D 1994 %T Modeling Windows in DOE 2.1E %A M. Susan Reilly %A Frederick C. Winkelmann %A Dariush K. Arasteh %A William L. Carroll %X
The most recent version of the DOE-2 building energy simulation program, DOE-2.1E, provides for more detailed modeling of the thermal and optical properties of windows. The window calculations account for the temperature effects on U-value, and update the incident angle correlations for the solar heat gain properties and visible transmittance. Initial studies show up to a 30% difference in calculating peak solar heat gain between the detailed approach and a constant shading-coefficient approach. The modeling approach is adapted from Lawrence Berkeley Laboratorys WINDOW 4 computer program, which is used in the National Fenestration Rating Council (NFRC) U-value rating procedure 100-91. This gives DOE-2.1E the capability to assess the annual and peak energy performance of windows consistent with the NFRC procedure. The program has an extensive window library and algorithms for simulating switchable glazings. The program also accounts for the influence of framing elements on the heat transfer and solar heat gain through the window.%B Thermal Performance of the Exterior Envelopes of Buildings V Conference %C Clearwater Beach, FL %8 12/1992 %G eng %L LBL-33192 %1
Windows and Daylighting Group%2 LBL-33192 %0 Conference Paper %B SPIE 13. International Symposium on Optical Materials Technology for Energy Efficiency and Solar Energy Conversion %D 1994 %T A Review of Electrochromic Window Performance Factors %A Stephen E. Selkowitz %A Michael D. Rubin %A Eleanor S. Lee %A Robert Sullivan %X
The performance factors which will influence the market acceptance of electrochromic windows are reviewed. A set of data representing the optical properties of existing and foreseeable electrochromic window devices was generated. The issue of reflective versus absorbing electrochromics was explored. This data was used in the DOE 2.1 building energy model to calculate the expected energy savings compared to conventional glazings. The effects of several different control strategies were tested. Significant energy and peak electric demand benefits were obtained for some electrochromic types. Use of predictive control algorithms to optimize cooling control may result in greater energy savings. Initial economic results considering annual savings, cooling equipment cost savings, and electrochromic window costs are presented. Calculations of thermal and visual comfort show additional benefits from electrochromics but more work is needed to quantify their importance. The design freedom and aesthetic possibilities of these dynamic glazings should provide additional market benefits, but their impact is difficult to assess at this time. Ultimately, a full assessment of the market viability of electrochromics must consider the impacts of all of these issues.%B SPIE 13. International Symposium on Optical Materials Technology for Energy Efficiency and Solar Energy Conversion %C Freiburg, Germany %8 04/1994 %G eng %L LBL-35486 %1
Windows and Daylighting Group%2 LBL-35486 %0 Conference Paper %B 13th SPIE International Symposium on Optical Materials Technology for Energy Efficiency and Solar Energy Conversion %D 1994 %T Simulating the Energy Performance of Holographic Glazings %A Konstantinos M. Papamichael %A Liliana O. Beltran %A Reto A. Furler %A Eleanor S. Lee %A Stephen E. Selkowitz %A Michael D. Rubin %X
The light diffraction properties of holographic diffractive structures present an opportunity to improve the daylight performance in side-lit office spaces by redirecting and reflecting sunlight off the ceiling, providing adequate daylight illumination up to 30 ft (9.14 m) from the window wall. Prior studies of prototypical holographic glazings, installed above conventional view windows, have shown increased daylight levels over a deeper perimeter area than clear glass, for selected sun positions. In this study, we report on the simulation of the energy performance of prototypical holographic glazings assuming a commercial office building in the inland Los Angeles climate.
The simulation of the energy performance involved determination of both luminous and thermal performance. Since the optical complexity of holographic glazings prevented the use of conventional algorithms for the simulation of their luminous performance, we used a newly developed method that combines experimentally determined directional workplane illuminance coefficients with computer-based analytical routines to determine a comprehensive set of daylight factors for many sun positions. These daylight factors were then used within the DOE-2.1D energy simulation program to determine hourly daylight and energy performance over the course of an entire year for four window orientations.
Since the prototypical holographic diffractive structures considered in this study were applied on single pane clear glass, we also simulated the performance of hypothetical glazings, assuming the daylight performance of the prototype holographic glazings and the thermal performance of double-pane and low-e glazings. The results of our analyses show that these prototypical holographic glazings did not save significant electric energy or reduce peak electricity demand compared to conventional energy-efficient window systems in inland Los Angeles office buildings, mainly because of their low diffraction efficiency. Finally, we address various design and implementation issues towards potential performance improvement.%B 13th SPIE International Symposium on Optical Materials Technology for Energy Efficiency and Solar Energy Conversion %C Freiburg, Germany %8 04/1994 %G eng %L LBL-35382 Rev. %1
Windows and Daylighting Group%2 LBL-35382R %0 Journal Article %J ASHRAE Transactions %D 1994 %T Spectrally Selective Glazings for Residential Retrofits in Cooling-Dominated Climates %A Eleanor S. Lee %A Deborah Hopkins %A Michael D. Rubin %A Dariush K. Arasteh %A Stephen E. Selkowitz %K deserts %K domestic %K energy conservation %K Glazing %K housing %K modernising %K subtropics %K usa %K windows %X
Spectrally selective glazings can substantially reduce energy consumption and peak demand in residences by significantly reducing solar gains with minimal loss of illumination and view. In cooling-dominated climates, solar gains contribute 24–31% to electricity consumption and 40–43% to peak demand in homes with single pane clear glazing—standard practice for residential construction built before the implementation of building energy efficiency standards. The existing residential housing stock therefore offers a prime opportunity for significant demand-side management (DSM),but the energy and cost savings must be weighed against retrofit first costs in order for the technology to achieve full market penetration. Using DOE-2.1D for numerical simulation of building energy performance, we quantify the energy and peak demand reductions, cost savings, and HVAC capacity reductions using spectrally selective glazings for five cooling-dominated climates in California. The cost-effectiveness of various material and installation retrofit options is discussed. Glazing material improvements for retrofit applications that are needed to achieve a prescribed cost savings are also given.%B ASHRAE Transactions %V 100 %G eng %N 1 %1
Windows and Daylighting Group%2 LBL-34455 %! ASHRAE Trans. %0 Conference Paper %B Materials Research Society %D 1993 %T Comparison of AIN Films Grown by RF at Magnetron Sputtering and Ion-Assisted Molecular Beam Epitaxy %A James S. Chan %A T.C. Fu %A Nathan W. Cheung %A Jennifer T. Ross %A Nathan Newman %A Michael D. Rubin %X
Crystalline aluminum nitride (AlN) thin films were formed on various substrates by using RF magnetron sputtering of an A1 target in a nitrogen plasma and also by ion-assisted molecular beam epitaxy (IAMBE). Basal-oriented AlN/(111) Si showed a degradation of crystallinity with increased substrate temperature from 550 to 770 °C, while the crystallinity of AlN/(0001) Al2O3 samples improved from 700 to 850 °C. The optical absorption characteristics of the AlN/(0001) Al2O3 films as grown by both deposition methods revealed a decrease in sub-band gap absorption with increased substrate temperature.%B Materials Research Society %C San Francisco, CA %V 300 %8 04/1993 %G eng %1
Windows and Daylighting Group%2 LBL-35660 %0 Conference Paper %B Annual IEEE-IAS Conference %D 1993 %T Developing Practical Reflectors for Cylindrical and Compact Fluorescent Lamps Based on Nonimaging Optics %A Michael Packer %A Francis M. Rubinstein %X
This paper investigates the application of nonimaging concentrators to the design of reflectors for luminaires. An interpretation of the concentration ratio — a statement of the conservation of flux — relative to the properties of a source and reflector is given. The result is used to develop practical compound parabolic (CP) reflector geometries that accommodate modern lamps. For the cylindrical and compact fluorescent lamps, we use the concentration ratio to show how the size and output performance of the CP reflector can be improved relative to the luminous and geometric properties of the lamp. The paper concludes by considering the addition of a nonimaging louver as a potentially significant design step once the reflector has been suitably designed relative to the lamp. It is noted that accurate data on the luminous emitting properties of lamps is a prerequisite to the development of optimum compact reflector designs.%B Annual IEEE-IAS Conference %C Toronto, Ontario, Canada %8 10/1993 %G eng %L LBL-35253 %1
Lighting Systems Group%2 LBL-35253 %0 Report %D 1993 %T The Energy Performance of Prototype Holographic Glazings %A Konstantinos M. Papamichael %A Liliana O. Beltran %A Reto A. Furler %A Eleanor S. Lee %A Stephen E. Selkowitz %A Michael D. Rubin %X
We report on the simulation of the energy performance of prototype holographic glazings in commercial office buildings in a California climate. These prototype glazings, installed above conventional side windows, are designed to diffract the transmitted solar radiation and reflect it off the ceiling, providing adequate daylight illumination for typical office tasks up to 10m from the window. In this study, we experimentally determined a comprehensive set of solar-optical properties and characterized the contribution of the prototype holographic glazings to workplane illuminance in a scale model of a typical office space. We then used the scale model measurements to simulate the energy performance of the holographic glazings over the course of an entire year for four window orientations (North, East, South and West) for the inland Los Angeles climate, using the DOE-2.lD building energy analysis computer program. The results of our experimental analyses indicate that these prototype holographic glazings diffract only a small fraction of the incident light. The results of this study indicate that these prototype holographic glazings will not save energy in commercial office buildings. Their performance is very similar to that of clear glass, which, through side windows, cannot efficiently illuminate more than a 4m - 6m depth of a building`s perimeter, because the cooling penalties due to solar heat gain are greater than the electric lighting savings due to daylighting.%8 02/1993 %G eng %1
Windows and Daylighting Group%2 LBL-34367 %0 Report %D 1993 %T Ion Implantation of Mg and C into GaN Films Grown by Ion-Assisted MBE %A Jennifer T. Ross %A Michael D. Rubin %A X. Yao %A Nathan Newman %A Amy Moll %G eng %1
Windows and Daylighting Group%2 LBL-34414 %0 Journal Article %J Applied Physics Letters %D 1993 %T P-Type Gallium Nitride by Reactive Ion-Beam Molecular Beam Epitaxy with Ion Implantation, Diffusion or Coevaporation of Mg %A Michael D. Rubin %A Nathan Newman %A James S. Chan %A T.C. Fu %A Jennifer T. Ross %K carrier density %K carrier mobility %K crystal doping %K diffusion %K evaporation %K gallium nitrides %K ion implantation %K magnesium additions %K molecular beam epitaxy %K p−type conductors %X
Gallium nitride is one of the most promising materials for ultraviolet and blue light‐emitting diodes and lasers. The principal technical problem that limits device applications has been achieving controllable p‐type doping. Molecular beam epitaxy assisted by a nitrogen ion beam produced p‐type GaN when doped via ion implantation, diffusion, or coevaporation of Mg. Nearly intrinsic p‐type material was also produced without intentional doping, exhibiting hole carrier concentrations of 5×1011 cm−3 and hole mobilities of over 400 cm2/V/s at 250 K. This value for the hole mobility is an order of magnitude greater than previously reported.%B Applied Physics Letters %V 64 %P 64-66 %G eng %N 1 %1
Windows and Daylighting Group%2 LBL-34413 %! Appl. Phys. Lett. %& 64 %R 10.1063/1.110870 %0 Conference Paper %B 2nd National New Construction Programs for Demand-Side Management Conference %D 1993 %T Realizing the DSM Potential of Integrated Envelope and Lighting Systems %A Stephen E. Selkowitz %A Eleanor S. Lee %A Francis M. Rubinstein %A Joseph H. Klems %A Konstantinos M. Papamichael %A Liliana O. Beltran %A Dennis L. DiBartolomeo %A Robert Sullivan %X
This report summarizes work to date on the development, implementation, and demonstration of integrated envelope and lighting systems. Two prototypes were developed through an iterative process of design and evaluation. A new method for quantifying the daylighting performance of optically complex systems was validated and used with the DOE-2 program to evaluate the energy performance of the systems. By implementing the prototypes in reduced scale, practical issues of how to build and control the systems are currently being resolved. Field tests with scale models will be used to determine daylighting and thermal performance in real-time under actual weather conditions. Demonstrations of the integrated systems either in part or as a whole system are being planned in parallel with several utility funded building programs to resolve real-world implementation under complex site, building, and cost constraints. Results of this second phase of research indicate that integrated systems offer solutions that not only achieve significant peak demand reductions but also realize consistent energy savings with added occupant comfort and satisfaction.%B 2nd National New Construction Programs for Demand-Side Management Conference %C San Jose, CA %8 10/1993 %G eng %L LBL-34731 %2 LBL-34731 %3
Integrated Systems%$
Commercial Building Systems%]
y%0 Report %D 1993 %T Window 4.0: Documentation of Calculation Procedures %A Elizabeth U. Finlayson %A Dariush K. Arasteh %A Charlie Huizenga %A Michael D. Rubin %A M. Susan Reilly %X
WINDOW 4.0 is a publicly available IBM PC compatible computer program developed by the Building Technologies Group at the Lawrence Berkeley Laboratory for calculating the thermal and optical properties necessary for heat transfer analyses of fenestration products. This report explains the calculation methods used in WINDOW 4.0 and is meant as a tool for those interested in understanding the procedures contained in WINDOW 4.0. All the calculations are discussed in the International System of units (SI).%G eng %L LBL-33943 %1
Windows and Daylighting Group%2 LBL-33943 %0 Conference Proceedings %B Thermal Performance of the Exterior Envelopes of Buildings V %D 1992 %T Affordable Housing Rehabilitation in Vermont: Energy Savings, Cost-Effectiveness, and Resident Satisfaction %A Richard C. Diamond %A Joseph A. McAllister %A Leo I. Rainer %A Ronald L. Ritschard %A Helmut E. Feustel %B Thermal Performance of the Exterior Envelopes of Buildings V %S Proceedings of the Thermal Performance of the Exterior Envelopes of Buildings V %C Clearwater, Florida %8 1992 %G eng %0 Conference Proceedings %B PLEA'92 Conference %D 1992 %T Climate Change and Passive Cooling in Europe %A Philip Haves %A Kenny, G. %A Susan Roaf %B PLEA'92 Conference %C Auckland, New Zealand %G eng %0 Conference Paper %B Materials Research Society Symposium %D 1992 %T Crystalline Growth of Wurtzite GAN on (111) GaAs %A Jennifer T. Ross %A Michael D. Rubin %A Ture K. Gustafson %X
Gallium Nitride films were grown on (111) Gallium Arsenide substrates using reactive rf magnetron sputtering. Despite a 20% lattice mismatch and different crystal structure, wurtzite GaN films grew epitaxially in basal orientation on (111) GaAs substrates. Heteroepitaxy was observed for growth temperatures between 550-600°C. X-ray diffraction patterns revealed (0002) GaN peak with a full-width-half-maximum (FWHM) as narrow as 0.17°. Possible surface reconstructions to explain the epitaxial growth are presented.%B Materials Research Society Symposium %V 242 %P 457 %G eng %1
Windows and Daylighting Group%2 LBL-32258 %R 10.1557/PROC-242-457 %0 Journal Article %J Thin Solid Films %D 1992 %T Effect of Deposition Pressure on the Microstructure and Electrochromic Properties of Electron-beam-evaporated Nickel Oxide Films %A Anoop Agrawal %A Hamid R. Habibi %A Raj K. Agrawal %A John P. Cronin %A Dale M. Roberts %A R'Sue Caron-Popowich %A Carl M Lampert %X
Electron-beam-evaporated nickel oxide films were shown to have a microcrystalline cubic nickel oxide structure. The pressure in the chamber during the film deposition has a large effect on the crystal size and the stoichiometry of the films. The redox currents, the efficiency of these films to color, and their optical properties were influenced by the processing conditions employed and the resulting microstucture. A model is proposed based on the observed microstructure that explains the source of overstoichiometric oxygen and ion transport in these films.%B Thin Solid Films %V 221 %P 239-253 %G eng %L LBNL-39077 %1
Windows and Daylighting Group%2 LBNL-39077 %0 Book Section %B Energy Efficient Buildings: A Design Guide %D 1992 %T Environmental Control in Energy Efficient Buildings %A Philip Haves %Y Susan Roaf %Y Mary E. Hancock %B Energy Efficient Buildings: A Design Guide %I Blackwell Scientific Publications Ltd %C Oxford %@ 0470219521 %G eng %0 Report %D 1992 %T Implementation of solar-reflective surfaces: materials and utility programs %A Sarah E. Bretz %A Hashem Akbari %A Arthur H. Rosenfeld %A Haider Taha %K Codes & Standards %K Heat Island %X
This report focuses on implementation issues for using solar-reflective surfaces to cool urban heat islands, with specific examples for Sacramento, California. Advantages of solar-reflective surfaces for reducing energy use are: (1) they are cost-effective if albedo is increased during routine maintenance; (2) the energy savings coincide with peak demand for power; (3) there are positive effects on environmental quality; and (4) the white materials have a long service life. Important considerations when choosing materials for mitigating heat islands are identified as albedo, emissivity, durability, cost, pollution and appearance. There is a potential for increasing urban albedo in Sacramento by an additional 18%. Of residential roofs, we estimate that asphalt shingle and modified bitumen cover the largest area, and that built-up roofing and modified bitumen cover the largest area of commercial buildings. For all of these roof types, albedo may be increased at the time of re-roofing without any additional cost. When a roof is repaired, a solar-reflective roof coating may be applied to significantly increase albedo and extend the life of the root Although a coating may be cost-effective if applied to a new roof following installation or to an older roof following repair, it is not cost-effective if the coating is applied only to save energy. Solar-reflective pavement may be cost-effective if the albedo change is included in the routine resurfacing schedule. Cost-effective options for producing light-colored pavement may include: (1) asphalt concrete, if white aggregate is locally available; (2) concrete overlays; and (3) newly developed white binders and aggregate. Another option may be hot-rolled asphalt, with white chippings. Utilities could promote solar-reflective surfaces through advertisement, educational programs and cost-sharing of road resurfacing.%I LBNL %C Berkeley, CA %P 67 %8 06/1992 %G eng %2 LBNL-32467 %R 10.2172/10172670 %0 Journal Article %J Journal of Vacuum Science Technology A %D 1992 %T Ion Assisted Sputtering of Tungsten Oxide Solar-Control Films %A Michael D. Rubin %X
Spectrally selective solar control films can greatly reduce solar heat gain from the infrared while admitting a high fraction of visible daylight. Single-crystal tungsten bronzes of general formula MxWO3, where M is a metal, can have sharp spectral selectivity, but this property is difficult to obtain in thin films. Reversible electrochromic coloration caused by insertion of alkali metal or hydrogen ions has been extensively studied in WO3. Polycrystalline films were made by reactive magnetron sputtering of WO3 together with substrate heating and/or ion bombardment. Bronze forming elements were introduced after deposition either by electrochemical injection of H+ or Li+ or by ion implantation of Ag and Cu. During deposition, HxWO3 or substoichiometric WOx could be formed by controlling the sputtering atmosphere. Films treated by ion bombardment had optical properties approaching those of single crystals.%B Journal of Vacuum Science Technology A %V 10 %P 1905-1907 %G eng %L LBL-32085 %1
Windows and Daylighting Group%2 LBL-32085 %0 Conference Proceedings %B 1992 ACEEE Summer Study on Energy Efficiency in Buildings %D 1992 %T Measured impact of neighborhood tree cover on microclimate %A David J. Sailor %A Leo I. Rainer %A Hashem Akbari %K Heat Island %K vegetation %X
In this paper we present results of our investigation into the relationship between urban microclimate and the local density of tree cover as measured in Sacramento, California. These results were obtained through analysis of data collected in a two-month long monitoring program with automatic weather stations installed at 15 residential locations throughout the city. Measured wind speeds showed a highly negative correlation with respect to tree cover. Daily peak air temperatures showed significant variation often differing from site to site by 2 to 4°C (approximately 3.5 to 7°F). A complex interaction between several competing factors is discussed leading to the conclusion that additional tree cover may actually increase urban air temperatures on synoptically cool days. It is suggested that this does not have a significant adverse affect in terms of overall summer urban cooling load. This is supported by an integrated analysis of the temperature data which yielded preliminary estimates indicating that residential cooling local (as measured by cooling degree days) may decrease by 5 to 10% per 10% increase in tree cover.%B 1992 ACEEE Summer Study on Energy Efficiency in Buildings %7 19 %V 9 %P 149-158 %8 1992/08 %G eng %U https://www.osti.gov/scitech/biblio/10103310 %0 Report %D 1992 %T Monitoring peak power and cooling energy savings of shade trees and white surfaces in the Sacramento Municipal Utility District (SMUD) service area: project design and preliminary results %A Hashem Akbari %A Sarah E. Bretz %A James W. Hanford %A Arthur H. Rosenfeld %A David J. Sailor %A Haider Taha %A Willem Bos %K Case Studies %K Heat Island %X
Urban areas in warm climates create summer heat islands of daily average intensity of 3-5 °C, adding to discomfort and increasing air-conditioning loads. Two important factors contributing to urban heat islands are reductions in albedo (lower overall city reflectance) and loss of vegetation (less evapotranspiration). Reducing summer heat islands by planting vegetation (shade trees) and increasing surface albedos, saves cooling energy, allows down-sizing of air conditioners, lowers air-conditioning peak demand, and reduces the emission of CO2 and other pollutants from electric power plants. The focus of this multi-year project, jointly sponsored by SMUD and the California Institute for Energy Efficiency (CIEE), was to measure the direct cooling effects of trees and white surfaces (mainly roofs) in a few buildings in Sacramento. The first-year project was to design the experiment and obtain base case data. We also obtained limited post retrofit data for some sites. This report provides an overview of the project activities during the first year at six sites. The measurement period for some of the sites was limited to September and October, which are transitional cooling months in Sacramento and hence the interpretation of results only apply to this period. In one house, recoating the dark roof with a high-albedo coating rendered air conditioning unnecessary for the month of September (possible savings of up to 10 kWh per day and 2 kW of non-coincidental peak power). Savings of 50% relative to an identical base case bungalow were achieved when a school bungalow's roof and southeast wall were coated with a high-albedo coating during the same period. DOE-2 simulations of these two buildings indicated savings of significantly lower magnitude than those measured. Given these results, the large measured savings may in part be attributed to generally lower insolation during the post-monitoring period. Our measured data for the vegetation sites do not indicate conclusive results because shade trees were small and the cooling period was almost over. We need to collect more data over a longer cooling season in order to demonstrate savings conclusively. The DOE-2 simulations of these buildings appear to indicate very small or no savings from trees. The issue of comparing DOE-2 simulations with measured data will be addressed in further detail during the second year of the project.%8 12/1992 %G eng %2 LBL-33342 %R 10.2172/10129204 %0 Report %D 1992 %T Optical Properties Database for High Performance Glazings %A M. Susan Reilly %A Stephen E. Selkowitz %A Frederick C. Winkelmann %X
This document presents the framework and foundation for an optical properties database undertaken as part of Subtask A.l, High-Performance Glazings, of Task 12 of the IEA Solar Heating and Cooling Program.
At the start of the Task, the participants agreed that a database of glazing optical properties would prove invaluable in the performance modeling of windows. The compilation of an optical properties database for glazing materials is intended to provide researchers with a common set of data for modeling fenestration systems and their components. The database also serves as a cross-reference for materials and products produced in different countries, and can be used for hourly annual building energy simulations programs such as DOE-2.1 E.
The WINDOW program for calculating the thermal performance of fenestration systems was used to establish the optical properties database. WINDOW 4.0 calculates the total window system thermal and optical properties. The format of the database is consistent with WINDOW 4.0 libraries that are directly accessible by WINDOW. The database contains the optical properties of commonly-found glazing systems and glazings, and is included in the appendices.
Future work on this database could include glazing and glazing system optical property data from each country, the collection of spectral data, the development of guidelines for reporting and methods for evaluating optically complex materials, and the establishment of a mechanism for maintaining the database.%G eng %L LBL-32616 %1
Windows and Daylighting Group%2 LBL-32616 %0 Report %D 1992 %T Spectrally Selective Glazings for Residential Retrofits %A Michael D. Rubin %A Dariush K. Arasteh %A Eleanor S. Lee %A Deborah Hopkins %X
A large fraction of Californias energy consumption and peak demand results from the need to cool residential buildings with high levels of solar heat gain transmitted through windows. For example, single family residences with central air conditioning built before 1978 consume from approximately 800 kWh per household in the Sacramento Municipal Utility District (SMUD) territory to 2,000 kwh per household within the northern Pacific Gas and Electric (PG&E) and Southern California Edison (SCE) central valley and inland territories. For a new demonstration home being built in the Sacramento area, SMUD reported that 52% of the peak summer cooling load was due to solar heat gain from windows. In cooling-dominated portions of California, where this energy problem is most severe, clear single-pane glass having the highest solar heat gain of any glazing type, is the most prevalent glazing found in existing residences.%G eng %L LBL-33774 %1
Windows and Daylighting Group%2 LBL-33774 %0 Journal Article %J Journal of Materials Research %D 1992 %T Sputtered YBCO Films on Metal Substrates %A E. Yin %A Michael D. Rubin %A M.A. Dixon %X
Magnetron sputtering was used to deposit superconducting YBCO thin films on four polycrystalline metal substrates. Yttrium-stabilized zirconia (YSZ) and silver were used as buffer layers. The thermal expansion coefficient of the substrate was apparently correlated to the properties of the superconductor. Auger depth profiles showed that the YSZ buffer blocked diffusion of most metal elements from the substrate. Nevertheless, contamination of the films depressed Tc to 81 K on Hastelloy × from 87 K on single-crystal strontium titanate. The films on metal substrates were c-axis oriented, but with random rotation in the a-b plane and smaller grain size than epitaxial films on single crystals. The weak links from these factors restrict Jc to 104 A/cm2 at 40 K.%B Journal of Materials Research %V 7 %P 1636-1640 %G eng %N 7 %1
Windows and Daylighting Group%2 LBL-32647 %& 1636 %R 10.1557/JMR.1992.1636 %0 Journal Article %J Journal of The Electrochemical Society %D 1992 %T Structure and Electronic Properties of Electrochromic NiO Films %A David A. Wruck %A Michael D. Rubin %K electrolytes %K nickel alloys %K sputter deposition %K thin films %K x-ray diffraction %K X-ray photoelectron spectra %X
Nickel oxide films were deposited by reactive RF magnetron sputtering. Optical and electrochemical characterization showed strong electrochrornic activity under certain deposition conditions. X-ray diffraction and infrared absorption measurements indicate that the films are polycrystalline NiO and that the bulk crystal structure does not change upon oxidation and reduction. Electronic conduction in the films and charge storage at the NiO|electrolyte interface were studied by dc resistance and ac impedance measurements. The infrared measurements and x-ray photoelectron spectroscopy were used to characterize changes in surface composition. We interpret the experimental results as follows: electrochromic activity requires a porous, granular NiO film with excess oxygen at the grain surfaces. The film is reduced by the transfer of protons from water molecules to oxygen ions at the solid surface, and the film is oxidized by the transfer of protons from the solid surface to hydroxyl ions in solution.%B Journal of The Electrochemical Society %V 140 %P 1097-1104 %G eng %N 4 %1
Windows and Daylighting Group%2 LBL-32598 %! J. Electrochem. Soc. %& 1097 %R 10.1149/1.2056205 %0 Report %D 1992 %T Switchable Window Modeling %A M. Susan Reilly %A Stephen E. Selkowitz %A Frederick C. Winkelmann %X
This document presents the work conducted as part of Subtask A.l, High-Performance Glazing, of Task 12 of the IEA Solar Heating and Cooling Program. At the start of the task, the participants agreed that chromogenic technology (switchable glazing) held considerable promise, and that algorithms to accurately model their dynamic behavior were needed.
The purpose of this subtask was to develop algorithms that could be incorporated into building energy analysis programs for predicting the thermal and optical performance of switchable windows. The work entailed a review of current techniques for modelling switchable glazing in windows and switchable windows in buildings and methods for improving upon existing modeling approaches. The proposed approaches correct some of the shortcomings in the existing techniques, and could be adapted for use in other similar programs. The proposed approaches generally provide more detailed calculations needed for evaluating the short-term (hourly and daily) impact of switchable windows on the energy and daylighting performance of a building. Examples of the proposed algorithms are included.%G eng %L LBL-32617 %1
Windows and Daylighting Group%2 LBL-32617 %0 Report %D 1992 %T Technology Reviews: Daylighting Optical Systems %A Jennifer E. Schuman %A Francis M. Rubinstein %A Konstantinos M. Papamichael %A Liliana O. Beltran %A Eleanor S. Lee %A Stephen E. Selkowitz %X
Conventional daylighting design components (i.e. fenestration systems) can normally provide adequate daylight in the perimeter of buildings, i.e. within 15 feet of windows or skylights. To provide daylight in a larger fraction of the building area requires one of two approaches. One option is to increase the fraction of the floor area that is adjacent to fenestration using architectural design strategies to alter floor plans from rectangular to reentrant forms, use of atria, stepping back upper stories of the building, etc. The second option is to use daylighting optical systems to deliver light to building locations beyond the perimeter zone. In this section, we present several technical approaches for introducing daylight and sunlight deeper within buildings. We consider situations where light transmission is desired over longer distances (15 - 100) and where it may be desirable to penetrate either horizontally or vertically through the core of a building. These includes daylighting techniques based on the use of light shelves, wide window sills, special reflectors, louvers, baffles, reflective blinds, and other ways to direct light deep into the buildings plan. These methods are intended to avoid the glare and the strong modulation (intense light near the window, rapidly falling off with increasing depth) of direct-beam daylighting.%G eng %L LBL-33203 %1
Windows and Daylighting Group%2 LBL-33203 %0 Report %D 1992 %T Technology Reviews: Dynamic Curtain Wall Systems %A Jennifer E. Schuman %A Francis M. Rubinstein %A Konstantinos M. Papamichael %A Liliana O. Beltran %A Eleanor S. Lee %A Stephen E. Selkowitz %X
This review addresses a technology area of interest for the future. Current systems falling into the category of dynamic envelopes are rare, of unknown cost effectiveness on a general basis, and probably most useful in climates harsher than in California. However, the concept of a dynamic envelope holds great promise for building optimization and perhaps even for a zero energy building perimeter. Future building technology developments are likely to include systems in this category, potentially leading to cost effect integrated systems that include the building skin as well as internal building systems. This technology section discusses rationale behind development of a dynamic building skin and presents the few existing examples in this category.
Building envelope design to date has addrcssed the combination of various materials and components to produce a building skin that will act primarily as a static banier to the extremities of the climate outside the envelope. This is in contrast to the dynamic behavior of an analogous system, our own skin. In the human body, the interface between internal and external environments is dynamically controlled through the complex interactions between the internal loads of the body, the thermal resistance of the clothing, and the conditions of the external environment such as air temperature, mean radiant temperature, air velocity and vapor pressure. Human beings have several means at their disposal to modify their comfort conditions, either through conscious thermo-regulatory control (e.g., removing clothing layers or changing locations) and/or through involuntary responses (e.g. sweat secretion or vasoconstriction). Our ability to dynamically use a variety of regulatory tools enables us to survive through a wide range of adverse conditions.%G eng %L LBL-33202 %1
Windows and Daylighting Group%2 LBL-33202 %0 Report %D 1992 %T Technology Reviews: Glazing Systems %A Jennifer E. Schuman %A Francis M. Rubinstein %A Konstantinos M. Papamichael %A Liliana O. Beltran %A Eleanor S. Lee %A Stephen E. Selkowitz %X
Glazing is a primary factor in the radiative, convective and conductive heat transfer through the building envelope and can be used to control or limit each of these energy flows. It is also the primary component in fenestration systems affecting the admission of natural light into buildings and thus critically affects the potential of energy savings through daylighting. Glazing is perhaps the building material with the broadest range of impact; its selection will affect all of the issues below.
Glazing impacts:
Windows and Daylighting Group%2 LBL-33204 %0 Report %D 1992 %T Technology Reviews: Lighting Systems %A Jennifer E. Schuman %A Francis M. Rubinstein %A Konstantinos M. Papamichael %A Liliana O. Beltran %A Eleanor S. Lee %A Stephen E. Selkowitz %X
This assessment examines several lighting technologies that have the potential to significantly impact the energy use for lighting in commercial buildings over the next five to ten years. The technologies are divided into four categories: sources, controls, and lighting quality. This is not a comprehensive list of every available new lighting technology. Energy-efficient technologies that are currently considered standard practice (e.g. energy efficient core coil ballasts for fluorescent lamps) are not included. In addition, technologies that are not projected to reach the market before 10 years are not included. The intent of this assessment is to highlight some of the most promising new technologies that appear to the have the largest widespread applicability in most commercial buildings. The fact that a particular technology does not appear on the list should not be construed to mean that the technology has no potential.%G eng %L LBL-33200 %1
Windows and Daylighting Group%2 LBL-33200 %0 Report %D 1992 %T Technology Reviews: Shading Systems %A Jennifer E. Schuman %A Francis M. Rubinstein %A Konstantinos M. Papamichael %A Liliana O. Beltran %A Eleanor S. Lee %A Stephen E. Selkowitz %X
Proper building envelope design is the most direct and efficient way to reduce cooling loads, by controling the radiative, convective and conductive heat transfer through the building envelope.
The most effective way to reduce cooling loads is to prevent their generation by controlling the output of the heat sources and the heat transfer through the building envelope. Heat sources can be either external, i.e., direct and diffuse solar radiation along with the associated convective and conductive heat transfer, or internal, i.e., electric lighting, equipment and building occupants. From these sources, only the electric lighting system can be partially controlled by the building designer with respect to output. The strategies to control the generation of cooling loads from the rest of the sources concentrate on the heat transfer modes through the building envelope, focusing on reducing heat transfer from the exterior to the interior and increasing heat transfer from the interior to the exterior.%G eng %L LBL-33201 %1
Windows and Daylighting Group%2 LBL-33201 %0 Journal Article %J Applied Physics Letters %D 1992 %T Thermodynamic and Kinetic Processes Involved in the Growth of Epitaxial GaN Thin Films %A Nathan Newman %A Jennifer T. Ross %A Michael D. Rubin %X
Our experimental results using reactive magnetron sputtering, combined with earlier literature, are used to understand the thermodynamic and kinetic processes involved in GaN film growth and the limiting factors involved in the incorporation of nitrogen during the growth process. We show that GaN films fabricated with low pressure growth techniques (< 0.1 Torr) such as sputtering and molecular beam epitaxy W E ) are formed under meta-stable conditions with a non equilibrium kinetically limited reaction. For these methods, the growth process is controlled by a competition between the forward reaction which depends on the arrival of activated nitrogen species at the growing surface and the reverse reaction whose rate is limited by the unusually large kinetic barrier of decomposition of GaN. In practice, the thermally activated rate of decomposition sets an upper bound to the growth temperature.%B Applied Physics Letters %V 62 %P 1242 %G eng %L LBL-32876 %1
Windows and Daylighting Group%2 LBL-32876 %0 Conference Paper %B Proceedings of the 1992 ACEEE Summer Study on Energy Efficiency in Buildings %D 1992 %T Utility and Economic Benefits of Electrochromic Smart Windows %A Jeffrey L. Warner %A M. Susan Reilly %A Stephen E. Selkowitz %A Dariush K. Arasteh %A Gregg D. Ander %X
Windows have very significant direct and indirect impacts on building energy consumption, load shape, and peak demand. Electrochromic switchable glazings can potentially provide substantial reductions in all aspects of cooling and lighting electricity usage. The solar-optical properties of electrochromic coatings vary over a wide range in response to an applied electrical signal. This control signal can be driven by a combination of occupant needs, external environmental conditions, building operating strategies, and electricity demand minimization requirements. The impact of an electrochromic glazing depends on the intrinsic properties of the coating, the placement of the coating within a window system, and many parameters related to building type, operating strategy, orientation, and location.
This study explores the potential benefits of electrochromics in comparison to other currently available and emerging glazing technologies. These effects are explored in office buildings in several climates as a function of window size, orientation, and building operating characteristics. The DOE-2 building energy simulation program was used to model the performances of these dynamic coatings, accounting for both thermal and daylighting impacts. Very substantial savings are demonstrated compared to conventional glazings, but specific impacts on component and total energy consumption, peak demand, and HVAC system sizing vary widely among the options analyzed. In a hot, sunny climate, probably the first niche market for electrochromics, simple payback periods of three to ten years were calculated based on an incremental glazing first cost of $15/ft2 to $25/ft2.
Electrochromic glazings appear to represent a very important future building design option that will allow architects and engineers a high degree of design freedom to meet occupant needs, while minimizing operating costs to building owners and providing a new and important electricity demand control option for utilities. Utility demand-side management programs can accelerate the market penetration of electrochromics by offering incentives to reduce net first cost and payback periods.%B Proceedings of the 1992 ACEEE Summer Study on Energy Efficiency in Buildings %C Pacific Grove, CA %8 08/1992 %G eng %L LBL-32638 %1
Windows and Daylighting Group%2 LBL-32638 %0 Journal Article %J Journal of Applied Physics %D 1992 %T Variational Theory of the Radiant Emittance of the Mercury Argon Discharge and the Effects of Isotopic Enrichment %A Robert W. Richardson %A Sam M. Berman %X
A variational theory of the radiant emittance of the mercury‐argon discharge is developed and applied to an investigation of the effects of alterations of the isotopic composition of the mercury. The theory includes the effects of transport of resonance radiation, elastic and inelastic collisions, resonant exchange of excitation, diffusion of the mercury atoms, the isotope‐ and hyperfine‐shifted structure of the resonance line, and the surfaces of the discharge on the emittance. Two sensitive parameters—the branching ratio for radiative decay of the resonance state and the rate constant for resonant exchange of excitation—are fitted to data on natural mercury. The remaining insensitive parameters are given values based on microscopic estimates. The resulting theory reproduces the experimentally observed results for mercury—196 enhanced mixtures. We predict small effects for mixtures with other isotopes enhanced. The crucial role played by resonant exchange of excitation is emphasized.%B Journal of Applied Physics %V 72 %P 5571-5578 %8 12/1992 %G eng %N 12 %1
Lighting Systems Group%2 LBL-31020 Rev. %& 5571 %R 10.1063/1.351956 %0 Journal Article %J Journal of Vacuum Science Technology A %D 1991 %T As-Sputtered Electrochromic Films of Nickel Oxide %A David A. Wruck %A M.A. Dixon %A Michael D. Rubin %A Susan N. Bogy %K absorptivity %K coloration %K electrochemical coating %K electrochromism %K hydroxyl radicals %K microstructure %K nickel %K nickel oxides %K sputtering %K thin films %X
Electrochromic nickel oxide films were deposited by radio-frequency magnetron sputtering of a Ni target in gas mixtures of Ar and O2. When electrochemically cycled in 0.1 N KOH solution, large reversible changes in visible absorption were obtained within the first 10 bleach/color cycles. Films which showed the greatest changes in optical properties and charge capacity were produced within a narrow range of oxygen flow rates. The coloration efficiency was found to be insensitive to the sputtering conditions and stoichiometry, with a value of 34+-4 cm2C-1 at 550 nm. This indicates that microstructure and charge capacity determine the absorption coefficient. The reaction rate was found to depend on the concentration of OH- in the electrolyte, indicating that OH- diffusion in the electrolyte limits the rate of reaction.%B Journal of Vacuum Science Technology A %V 9 %P 2170-2173 %8 02/1991 %G eng %N 4 %1
Windows and Daylighting Group%2 LBL-30066 %! J. Vac. Sci. Technol. A %& 2170 %R 10.1116/1.577245 %0 Report %D 1991 %T Automatic Lighting Controls Demonstration: Long-term Results %A Francis M. Rubinstein %A Rudolph R. Verderber %X
An advanced electronically ballasted lighting control system was installed in a portion of an office building to measure the energy and demand savings.
The lighting control system used an integrated lighting control scenario that included daylight following, lumen depreciation correction, and scheduling. The system reduced lighting energy on weekdays by 62% and 51% in the north and south daylit zones, respectively, compared to a reference zone that did not have controls. During the summer, over 75% energy savings were achieved on weekdays in the north daylit zone. Even in the south interior zone, which benefited little from daylight, correction strategies (scheduling and lumen depreciation) and adjustment of the aisleway lights to a low level resulted in energy use of only half that of the reference zone. Although, in general, the savings varied over the year due to changing daylight conditions, the energy reduction achieved with controls could be fit using a simple analytical model (Figure ES-1).
Significant savings also occurred during core operating hours (6 A.M. to 6 P.M.) when it is more expensive to supply and use energy. Compared to the usage in the reference zone, energy reductions of 49%, 44%, and 62% were measured in the south daylit, south interior, and north daylit zones, respectively, during core operating hours throughout the year.
Lighting energy usage on weekends decreased dramatically in the zones with controls, with the usage in the north daylit zone only 10% that of the reference zone.
A simple survey developed to assess occupant response to the lighting control system showed that the occupants were satisfied with the light levels provided.
During the load-shedding test, the lighting control system was used to lower light levels by about 15% for short intervals in the afternoons in simulated response to a peak demand situation. The dimming controls were effective in implementing load-shedding control; occupant response to the strategy was neutral.
A novel two-part control photosensor was effective in providing appropriate control; it allowed daylighting and lumen maintenance strategies to be implemented simultaneously with the same hardware. With this photocontrol system, design light levels were maintained at the workplane regardless of the daylight contribution or the age of the lighting system.%B PG&E Research and Development %8 07/1991 %G eng %L LBL-28793 %1
Lighting Systems Group%2 LBL-28793 %0 Conference Paper %B IEEE-IAS Annual Conference %D 1991 %T Considering Lighting System Performance and HVAC Interactions in Lighting Retrofit Analysis %A Ellen M. Franconi %A Francis M. Rubinstein %X
The performance of several typical fluorescent lighting retrofits are examined using analysis methods of varying sophistication. Estimates of energy and lighting performance based on the simple non-application specific data generally available tend to overestimate the energy savings obtained with the various retrofits by 10-30%. Adding a simple correction to account for cooling benefits exacerbates the error unless heating penalties are also considered. An analysis method that takes into account the thermal application factor of the lighting system shows that the error is typically due to systematically overestimating the energy usage of the original lighting system. If thermal application factor is considered, then detailed HVAC calculations do not significantly improve the energy-savings estimate.%B IEEE-IAS Annual Conference %C Houston, TX %8 10/1992 %G eng %L LBL-33475 %1
Lighting Systems Group%2 LBL-33475 %0 Conference Paper %B Association of Energy Engineers Conference %D 1991 %T Fixture Efficiency Program %A Michael J. Siminovitch %A Francis M. Rubinstein %A Michael Packer %B Association of Energy Engineers Conference %C Anaheim, CA %8 04/1991 %G eng %L LBL-30646 %1
Lighting Systems Group%2 LBL-30646 %0 Journal Article %J Theoretical and Applied Climatology %D 1991 %T Heat island and oasis effects of vegetative canopies: micro-meteorological field-measurements %A Haider Taha %A Hashem Akbari %A Arthur H. Rosenfeld %K Heat Island %K vegetation %X
Dry-bulb temperature, dew-point, wind speed, and wind direction were measured in and around an isolated vegetative canopy in Davis CA from 12 to 25 October 1986. These meteorological variables were measured 1.5 m above ground along a transect of 7 weather stations set up across the canopy and the upwind/downwind open fields. These variables were averaged every 15 minutes for a period of two weeks so we could analyze their diurnal cycles as well as their spatial variability. The results indicate significant nocturnal heat islands and daytime oases within the vegetation stand, especially in clear weather. Inside the canopy within 5 m of its upwind edge, daytime temperature fell by as much as 4.5°C, whereas the nighttime temperature rose by 1°C. Deeper into the canopy and downwind, the daytime drop in temperature reached 6°C, and the nighttime increase reached 2°C. Wind speed was reduced by ~ 2 ms-1 in mild conditions and by as much as 6.7 ms-1 during cyclonic weather when open-field wind speed was in the neighborhood of 8 ms-1. Data from this project were used to construct correlations between temperature and wind speed within the canopy and their corresponding ambient, open-field values.%B Theoretical and Applied Climatology %V 44 %P 123-138 %G eng %R 10.1007/BF00867999 %0 Journal Article %J Mater. Lett %D 1991 %T High Quality GaN Grown by Reactive Sputtering %A Jennifer T. Ross %A Michael D. Rubin %X
Gallium nitride films were grown by reactive rf magnetron sputtering on sapphire substrates. Crystalline (1120) GaN films were obtained on (0112) sapphire at substratestemperatures between 640-680 °C. High N2 partial pressures are required to crystalize the GaN films. Nitrogen incorporation and crystal quality of GaN films are examined as a function of substrate temperature and nitrogen partial pressure. Band gaps of 3.4 eV, and photoluminescence peaks as narrow as 11 meV are reported for sputtered GaN films.%B Mater. Lett %V 12 %P 215 %G eng %L LBL-31726 %1
Windows and Daylighting Group%2 LBL-31726 %0 Report %D 1991 %T Multifamily Energy Audit for HUD-Insured Multifamily Properties %A Richard C. Diamond %A Joseph A. McAllister %A Leo I. Rainer %B Document prepared for the Office of Multifamily Housing, U.S. Department of Housing and Urban Development %I Lawrence Berkeley National Lab %C Berkeley %8 11/1991 %G eng %0 Journal Article %J Materials Letters %D 1991 %T On-Axis Shielded Sputtering of Y-Ba-Cu-O %A E. Yin %A Michael D. Rubin %A C. Bradford Hopper %X
In the standard process for sputtering of YBCO, the substrate is located off the axis of the target. High pressures are used to avoid and slow bombardment of the growing film by high-energy oxygen atoms. Using a particle shield and dc bias, we have deposited high quality YBCO films on axis at significantly reduced pressures. Typically these films have better and more repeatable electrical properties than off-axis films, and deposition rates are 2 to 3 times faster. Even more important is the return to a geometry that is inherently scalable to large-area deposition.%B Materials Letters %V 13 %P 89-92 %8 03/1992 %G eng %N 2-3 %1
Windows and Daylighting Group%2 LBL-31017 %& 89 %R 10.1016/0167-577X(92)90114-Y %0 Journal Article %J Journal of Materials Research %D 1991 %T Single Crystal Wurtzite GaN on (111) GaAs with AIN Buffer Layers Grown by Reactive Magnetron Sputter Deposition %A Jennifer T. Ross %A Michael D. Rubin %A Ture K. Gustafson %X
We report the growth conditions necessary for highly oriented wurtzite GaN films on (111) GaAs, and single crystal GaN films on (111) GaAs using AIN buffer layers. The GaN films and AlN buffers are grown using rf reactive magnetron sputter deposition. Oriented basal plane wurtzite GaN is obtained on (111) GaAs at temperatures between 550-620 °C. However, using a high temperature 200 Å AIN buffer layer epitaxial GaN is produced. Crystal structure and quality is measured using x-ray diffraction (XRD), reflection electron diffraction (RED), and a scanning electron microscope (SEM). This is the first report of single crystal wurtzite GaN on (111) GaAs using AlN buffer layers by any growth technique. Simple AlN/GaN heterostructures grown by rf reactive sputter deposition on (111) GaAs are also demonstrated.%B Journal of Materials Research %V 8 %P 2613-2616 %8 10/1993 %G eng %N 10 %1
Windows and Daylighting Group%2 LBL-33362 %& 2613 %0 Conference Paper %B Illuminating Engineering Society Annual Conference 1991 %D 1991 %T A Spreadsheet for Analyzing the In-Situ Performance of Fluorescent Luminaries %A Francis M. Rubinstein %A Chin Zhang %X
A spreadsheet program for determining system efficacy, power input and light output of common 4 ft fluorescent lighting systems under realistic operating conditions is described. The program uses accepted IES engineering principles to precisely account for ballast factor, existing thermal conditions and maintenance practices. The spreadsheet, which includes a data base of lamp and ballast performance data, can be used to calculate the cost-effectiveness of many common lighting retrofits.%B Illuminating Engineering Society Annual Conference 1991 %C Montreal, Canada %8 08/1991 %G eng %L LBL-30648 %1
Lighting Systems Group%2 LBL-30648 %0 Journal Article %J Journal of Optometry and Vision Science %D 1991 %T Visual Performance at Video Display Terminals--Effects of Screen Color and Illuminant Type %A Thomas W. Raasch %A Ian L. Bailey %A Peter A. Howarth %A Daniel S. Greenhouse %A Sam M. Berman %X
A limited set of illuminants and phosphor colors are commonly used in video display terminal (VDT) working environments. This study attempts to identify any combinations of such conditions that influence performance on a visually demanding counting task. Experiments were performed to test whether the phosphor color, ambient lighting spectrum, or temporal frequency characteristics of the display and ambient lighting could alter performance. Under conditions where potentially contaminating variables such as reflectance level and screen glare patterns were equalized, no significant differences in performance were produced by the particular sets of stimulus conditions tested. The results suggest that displays and illuminant types that are in common use allow substantially equivalent visual performance.%B Journal of Optometry and Vision Science %V 68 %P 924-929 %G eng %L LBL-37013 %1
Lighting Systems Group%2 LBL-37013 %0 Conference Paper %B IEEE-IAS Annual Conference, October 7-1, 1990 %D 1990 %T 50% Energy Savings with Automatic Lighting Controls %A Francis M. Rubinstein %A Michael J. Siminovitch %A Rudolph R. Verderber %K lighting control %K photoelectric cells %K scheduling %X
An electronically ballasted lighting control system that was demonstrated at an office building is described. The system demonstrated the energy savings and demand reduction capabilities of a lighting control system designed to exploit all major control strategies, including scheduling, daylighting and lumen maintenance. After nine months of operation, lighting energy savings of approximately 50% relative to previous usage have been consistently achieved. A two-part control photocell, shown to be effective at maintaining light levels at the workplane regardless of the daylight contribution, is presented.%B IEEE-IAS Annual Conference, October 7-1, 1990 %I IEEE %C Seattle, WA %V 2 %8 10/1990 %@ 0-87942-553-9 %G eng %1
Lighting Systems Group%2 LBL-30179 %R 10.1109/IAS.1990.152154 %0 Conference Proceedings %B 1990 ACEEE Summer Study on Energy Efficiency in Buildings %D 1990 %T Conservation Screening Curves to Compare Efficiency Investments to Power Plants: Applications to Commercial Sector Conservation Programs %A Jonathan G. Koomey %A Arthur H. Rosenfeld %A Ashok J. Gadgil %B 1990 ACEEE Summer Study on Energy Efficiency in Buildings %7 August 28-September 3 %I American Council for an Energy Efficient Economy %C Asilomar, CA %V 5 %P 5.115-5.124 %G eng %6 10 %0 Journal Article %J Journal of Materials Research %D 1990 %T Optical and Mechanical Properties of DC Sputtered Carbon Films %A Michael D. Rubin %A C. Bradford Hopper %A Nam-Hee Cho %A Bharat Bhushan %X
Amorphous carbon films were deposited on glass by d.c. magnetron sputtering from a graphite target in mixtures of argon and hydrogen. Hydrogen flow and other deposition parameters affected the optical and mechanical properties of these films. Increasing hydrogen content caused the average visible transmittance to vary from 16% to 86% for 500-Å thick films. Maximum compressive stress and hardness occur between 0-1% hydrogen flow, resulting in rapid delamination. Low sputtering power moderately increases transmittance and hardness while relieving stress. Transparency is induced in both the high-hydrogen and low-power films by formation of sp3 C-C bonds. In the case of the hydrogenated films, however, a softer polymeric structure is formed.%B Journal of Materials Research %V 5 %P 2538-2542 %8 11/1990 %G eng %N 11 %1
Windows and Daylighting Group%2 LBL-28826 %& 2538 %R 10.1557/JMR.1990.2538 %0 Conference Proceedings %B Proceedings of the 1990 ASHRAE Winter Conference %D 1990 %T Summer heat islands, urban trees, and white surfaces %A Hashem Akbari %A Arthur H. Rosenfeld %A Haider Taha %X
Temperature trends for the last 100 years in several US cities were analyzed. Since approximately 1940 there has been a steady overall increase in urban temperatures. Summer monthly averages have increased by 0.25-1°F per decade (approximately 1°F for larger cities like Los Angeles and 0.25°F for smaller cities). There is no evidence that this rise is moderating, and of course global greenhouse warming will add a comparable rise. Typical electric demand of cities increases by 1% to 2% of the peak for each °F and most major cities are now approximately 5°F warmer than they were in the early 1900s. Hence, we estimate that about 5% to 10% of the current urban electric demand is spent to cool buildings just to compensate for the heat island effect. For example, downtown Los Angeles is now 5°F hotter than in 1940 and so the L.A. basin demand is up by 1500 MW, worth $150,000 per hour on a hot afternoon (the equivalent national bill is approximately$1M/hour). In major cities, smog episodes are absent below about 70°F, but they become unacceptable by 90°F, so a rise of 10°F because of past and future heat island effects is very significant. There are some strategies that can alleviate the heat island effect. Computer simulations and field studies have quantified the potential of trees and lighter surfaces for reducing summer heat islands. Results indicate that the cost of saved energy and avoided CO2, through greening and whitening of urban areas, is less than 1 cents kWh and 2 cents/kg of carbon, respectively.%B Proceedings of the 1990 ASHRAE Winter Conference %8 1990/february 11 %G eng %U http://isswprod.lbl.gov/library/view-docs/public/output/LBL-28308.pdf %0 Journal Article %J Solar Energy Materials %D 1990 %T Thermal and Optical Analysis of Switchable Window Glazings %A M. Susan Reilly %A Dariush K. Arasteh %A Stephen E. Selkowitz %X
Glazing materials with variable optical properties (switchable glazings) offer the ultimate in control over the light and energy entering a building. Products of this kind are in their initial stages of development, and guidelines that relate window energy performance to glazing material properties are needed. Though the use of a computer program for calculating window thermal and optical performance parameters, we evaluated (1) the relative performances of three switchable glazings prototypes with differing solar transmittance spectra; (2) the differences between glazings that switch from transmitting to reflecting and those that switch from transmitting to absorbing; and (3) the effects of positioning the switchable glazing in a window. We focused on design conditions for cooling-dominated buildings, since switchable glazings are expected to reduce cooling and lighting loads. We conclude that the differences in thermal performance between absorbing and reflecting switchable glazings can be eliminated through proper placement of the glazing in a window system and through the use of other spectrally selective glazings.%B Solar Energy Materials %V 22 %G eng %L LBL-29629 %1
Windows and Daylighting Group%2 LBL-29629 %0 Conference Paper %B 1990 HVAC and Building Systems Congress, October 7-12, 1990 %D 1990 %T Thermal Performance Characteristics of Compact Fluorescent Fixtures %A Michael J. Siminovitch %A Francis M. Rubinstein %A Richard E. Whiteman %X
This paper describes the thermal and light output performance variations for some representative compact fluorescent fixtures. Experimental data is presented showing the changes in relative light output and temperature for both screw-in and dedicated compact fluorescent fixtures systems. Initial experimental data shows that substantial losses in fixture efficiency can occur in compact fluorescent fixtures due to elevated temperature conditions inside the lamp compartment. These elevated temperatures affect the minimum lamp wall temperature of the compact fluorescent lamp and the corresponding light output and efficacy characteristics of the lamp ballast system. This paper also presents experimental data on various methods to reduce compartment and lamp wall temperatures in order to increase fixture efficiency.%B 1990 HVAC and Building Systems Congress, October 7-12, 1990 %C Seattle, WA %8 3/1990 %G eng %1
Lighting Systems Group%2 LBL-28791 %0 Conference Paper %B IEA/ENEL Conference on Advanced Technologies for Electric Demand-Side Management %D 1990 %T Thermally Efficient Compact Fluorescent Fixture Systems %A Michael J. Siminovitch %A Francis M. Rubinstein %A Michael Packer %X
Compact fluorescent lamps that can be inserted into conventional light fixtures are rapidly gaining acceptance as both a viable retrofit and new design approach to reducing lighting loads. Ideally, the compact fluorescent lamp should have the same light output as the incandescent lamp it replaces, but overheating inside typically small enclosed fixtures can reduce lumen output and hence lighting fixture efficiency by 15 to 20 percent. Fortunately, simple fixture modifications can erase this efficiency penalty, so that the full efficiency benefit of replacing incandescent lamps with fluorescent lamps can be realized. The paper describes such modifications and presents experimental data documenting the potential efficiency enhancement associated with thermal control systems.%B IEA/ENEL Conference on Advanced Technologies for Electric Demand-Side Management %C Sorrento, Italy %8 04/1991 %G eng %L LBL-30180 %1
Lighting Systems Group%2 LBL-30180 %0 Conference Paper %B IEEE-IAS Annual Conference %D 1990 %T Thermally Efficient Compact Fluorescent Fixtures %A Michael J. Siminovitch %A Francis M. Rubinstein %A Richard E. Whiteman %X
This paper describes the development of thermally efficient compact fluorescent futures. Experimental data shows that decreases in fixture effiaency can approach 20% due to elevated temperature conditions inside the lamp compartment. These elevated temperatures increase the minimum lamp wall temperature of the compact fluorescent lamp and reduce the light output and efficacy of the lamp ballast system.
A series of prototype fixtures are described that employ convective venting and heat sinking to reduce elevated lamp temperatures. These cooling strategies can produce 20% increases in light output and efficacy.%B IEEE-IAS Annual Conference %C Seattle, WA %8 10/1990 %G eng %L LBL-29294 %1
Lighting Systems Group%2 LBL-29294 %0 Journal Article %J Electrical Systems Design %D 1990 %T Using CAD for Lighting Design Helps Predict the Unpredictable %A Gregory J. Ward %A Anat Grynberg %A Charles K. Ehrlich %A Francis M. Rubinstein %X
Part of a lighting designers craft is to imagine the appearance of an illuminated area before it is built. Experienced designers, however, can be surprised once construction begins. New uses of construction materials, new techniques and experimentation often lead to profitable discoveries as well as occasional mistakes. Design exploration is to be encouraged, as long as it does not conflict with a clients preference. Unfortunately, a client may insist on an unwise choice, resulting in confrontation and potential dissatisfaction. For these reasons and others, designers and their clients frequently prefer to preview many decisions before they are made.
Computers offer the ability to predict variables in design including appearance, thereby making designer and client education more economical. By simulating the behavior of light, computers can predict luminance and illuminance levels, and make synthetic images of a space before it is built. In lighting design, a common practice is to begin with a target illuminance distribution, then use manufacturers tables and simple calculations to arrive at an initial lighting arrangement. For critical areas, flexibility is built into the system so that the light distribution can be tuned during installation. This approach works well in most applications, but when daylighting is a key feature, or aesthetics are stressed over illumination levels, it becomes much more difficult for the designer to be convinced, and even harder to convince the client of a quality design. In this situation computer prediction of appearance would be invaluable.%B Electrical Systems Design %V 70 %P 26-31 %8 04/1990 %G eng %1
Lighting Systems Group%2 LBL-28499 %& 26 %0 Journal Article %J ASHRAE Transactions %D 1990 %T Window Nighttime U-Values: A Comparison Between Computer Calculations and MoWiTT Measurements %A Joseph H. Klems %A M. Susan Reilly %X
For six windows the U-values measured with the MoWiTT under field conditions are compared with detailed U-value calculations for the same conditions using the programs WINDOW and ANSYS. There is good agreement between measurements and calculations.%B ASHRAE Transactions %V 96 %G eng %L LBL-28452 %1
Windows and Daylighting Group%2 LBL-28452 %0 Report %D 1989 %T Conservation Screening Curves to Compare Efficiency Investments to Power Plants %A Jonathan G. Koomey %A Arthur H. Rosenfeld %A Ashok J. Gadgil %K Enduse %K Energy End-Use Forecasting %K EUF %I Lawrence Berkeley National Laboratory %P 20 %8 10/1989 %@ LBNL-27286 %G eng %2 LBNL-27286 %0 Conference Paper %B IEEE-IAS Annual Conference %D 1989 %T The Effect of Luminaire Type and Spacing on Visibility Levels in Unobstructed Spaces %A Francis M. Rubinstein %A Michael Packer %X
The study examines how luminaire type and spacing affect task contrast and visibility in unobstructed office spaces. The Lumen-Micro program was used to calculate visibility levels in a model open-office space as a function of luminaire candlepower distribution, fixture spacing, and illuminance level. Three representative luminaires were parametrically examined: a lensed troffer, a high-performance parabolic, and a high-performance uplight. Small differences in average task visibility levels were observed for the different luminaires and fixture spacings examined, but these differences were slight compared with variability within an installation. The study indicates that if one does not know the location of the task a priori, then it is not possible to achieve consistently high visibility levels throughout a space without resorting to lighting solutions that are intrinsically inefficient.%B IEEE-IAS Annual Conference %C San Diego, CA %8 10/1989 %G eng %L LBL-30178 %1
Lighting Systems Group%2 LBL-30178 %0 Journal Article %J Solar Energy Materials %D 1989 %T The Effects of Infrared Absorbing Gasses on Window Heat Transfer: A Comparison of Theory and Experiment %A M. Susan Reilly %A Dariush K. Arasteh %A Michael D. Rubin %X
This paper extends an existing heat transfer model of multipane windows filled with gasses to include the effects of infrared absorption within the gasses. A one-dimensional, finite-element, control-volume approach for calculating the heat transfer across a horizontal window filled with an infrared absorbing gas is presented. This model includes the coupled effects of conduction and radiation but not convection. Experimental data on the heat transfer rates through windows filled with infrared absorbing gasses and heated from above (to minimize convection) agree with results from this model. Infrared absorbing gasses are shown to have a small effect on reducing heat transfer through common window systems and are not as effective as low-emittance coatings for reducing radiative heat transfer.%B Solar Energy Materials %V 20 %P 277-288 %G eng %L LBL-29389 %1
Windows and Daylighting Group%2 LBL-29389 %0 Conference Paper %B AEE-World Energy Engineering Congress %D 1989 %T The Energy Conservation Potential Associated with Thermally Efficient Fluorescent Fixtures %A Michael J. Siminovitch %A Francis M. Rubinstein %A Rudolph R. Verderber %A Douglas G. Crawford %X
This paper describes the energy conservation potential associated with thermally efficient fluorescent fixtures. Various approaches to improving fixture efficiency through the optimization of lamp wall temperature are discussed. The energy saving potential using thermally efficient fixtures is estimated for a sample lighting layout for an office space. This analysis indicates that both power density and the number of fixtures can be reduced with thermally efficient fixtures. Conservation potential on a national level is also estimated, using market profiles obtained from fixture manufacturers in conjunction with measured fixture performance data.%B AEE-World Energy Engineering Congress %C Atlanta, GA %8 10/1989 %G eng %L LBL-27315 %1
Lighting Systems Group%2 LBL-27315 %0 Journal Article %J Journal of Applied Physics %D 1989 %T Ion Implantation of Sputtered Y-Ba-Cu-O Films %A Michael D. Rubin %A Ian G. Brown %A E. Yin %A David A. Wruck %K copper %K ion implantation %K sputter deposition %K Thin film deposition %K thin films %X
Thin films of Y‐Ba‐Cu‐O were deposited by rf magnetron sputtering from a single stoichiometric target and then altered in composition by ion implantation. Under optimum deposition conditions the films are deficient in Ba and Cu. Ion implantation of Cu was performed using a metal‐vapor vacuum‐arc source having high current and a broad energy spectrum for good depth distribution. Composition was determined by Rutherford backscattering spectrometry. The zero‐resistance temperature was greatly increased after implantation and reannealing. This method could be used to write superconducting patterns on insulating material.%B Journal of Applied Physics %V 66 %P 3940-3942 %8 10/1989 %G eng %1
Windows and Daylighting Group%2 LBL-26858 %& 3940 %R 10.1063/1.344023 %0 Conference Paper %B Building Simulation Conference %D 1989 %T Luminance in Computer-Aided Lighting Design %A Gregory J. Ward %A Francis M. Rubinstein %A Anat Grynberg %B Building Simulation Conference %C Vancouver, Canada %8 06/1989 %G eng %L LBL-33404 %1
Lighting Systems Group%2 LBL-33404 %0 Report %D 1989 %T Photoelectric Control of Daylight-Following Lighting Systems %A Francis M. Rubinstein %A Rudolph R. Verderber %A Gregory J. Ward %X
The ability of daylight-following lighting systems to provide a minimum specified light level at the task surface is influenced by 1) the control algorithm used, 2) the spatial response of the ceiling-mounted control photosensor and 3) the location of the photosensor relative to task and window. Best performance was obtained with a closed-loop proportional control system controlled by a photosensor, with a large field of view but shielded from direct light from the window. A minimum specified illuminance level could be maintained at specific points on the task surface regardless of daylight condition or room geometry provided that the system gain was properly calibrated to account for the local luminous environment.
Open-loop proportional control also performed adequately but offered less precise control than closed-loop systems due to the necessity of using a photosensor that was not shielded from direct window light. Integral-reset systems that were tested performed poorly, but performance could be improved slightly by completely shielding the photocell from direct window light.%8 02/1989 %G eng %1
Lighting Systems Group%2 LBL-24872 %0 Conference Proceedings %B International Society for Optics and Photonics (SPIE) %D 1989 %T Spatial Adaptation on Video Display Terminals %A Daniel S. Greenhouse %A Ian L. Bailey %A Peter A. Howarth %A Sam M. Berman %Y Bernice E. Rogowitz %X
Spatial adaptation, in the form of a frequency-specific reduction in contrast sensitivity, can occur when the visual system is exposed to certain stimuli. We employed vertical sinusoidal test gratings to investigate adaptation to the horizontal structure of text presented on a standard video display terminal. The parameters of the contrast sensitivity test were selected, on the basis of waveform analysis of spatial luminance scans of the text stimulus. We found. that subjects exhibited a small, but significant, frequency-specific adaptation consistent with the spatial frequency spectrum of the stimulus. Theoretical and practical significance of this finding are discussed.%B International Society for Optics and Photonics (SPIE) %S Human Vision, Visual Processing, and Digital Display %V 1077 %P 27-34 %8 08/1989 %G eng %L LBL-2837 %1
Lighting Systems Group%2 LBL-28376 %R 10.1117/12.952699 %0 Journal Article %J Thin Solid Films %D 1989 %T Sputtered Electrochromic V2O5 Films %A David A. Wruck %A S. Ramamurthi %A Michael D. Rubin %X
Vanadium oxide films were deposited by reactive dc magnetron sputtering from a vanadium target in argon-oxygen gas mixtures. The composition and structure of these films were investigated by X-ray photoelectron spectroscopy and X-ray diffraction. Films with the approximate composition V2O5 were amorphous when deposited at room temperature and had a reversible color change when lithium was electrochemically injected. Because the color change is slight, these films could be used as a counterelectrode to a more strongly coloring material.%B Thin Solid Films %V 182 %P 79-85 %8 12/1989 %G eng %N 1-2 %1
Windows and Daylighting Group%2 LBL-26864 %& 79 %R 10.1016/0040-6090(89)90245-9 %0 Journal Article %J ASHRAE Transactions %D 1989 %T A Versatile Procedure for Calculating Heat Transfer Through Windows %A Dariush K. Arasteh %A M. Susan Reilly %A Michael D. Rubin %X
Advances in window technologies and the desire to standardize the reporting of standardswindow heat transfer indices have necessitated the development of a comprehensivesanalytical procedure for calculating heat transfer through windows. This paper showsshow complete window heat transfer can be considered as the area-weighted sum of thesthree window component areas: the center-of-glass area, the edge-of-glass area, and thesframe area. Algorithms for calculating heat transfer through each of these areas and forscombining these to calculate total window indices are presented.%B ASHRAE Transactions %V 95 %G eng %L LBL-27534 %1
Windows and Daylighting Group%2 LBL-27534 %0 Conference Paper %B IEEE-IAS Annual Conference %D 1988 %T Control of Lamp Wall Temperature %A Rudolph R. Verderber %A Francis M. Rubinstein %A Michael J. Siminovitch %X
A review of techniques to control the lamp wall temperature of fluorescent lamps in luminaires is presented. Past results show large increases in efficacy and light output can be obtained (to 25%) if the lamps can be operated at their optimum lamp wall temperature. It may be judicious to review their cost effectiveness in view of the increased energy cost and advances in the devices technology.%B IEEE-IAS Annual Conference %C Minneapolis, MN %8 10/1988 %G eng %L LBL-25430 %1
Lighting Systems Group%2 LBL-25430 %0 Report %D 1988 %T Design Criteria for a Consumer Energy Report: A Pilot Field Study %A Linda L. Layne %A Willett Kempton %A Alfredo Behrens %A Richard C. Diamond %A Margaret F. Fels %A Cathy Reynolds %I Princeton University %C Princeton %8 01/1988 %G eng %0 Journal Article %J Journal of Optometry and Vision Science %D 1988 %T Human Electroretinogram Responses to Video Displays %A Sam M. Berman %A Daniel S. Greenhouse %A Ian L. Bailey %A Robert D. Clear %A Thomas W. Raasch %X
Time-averaged human electroretinogram (ERG) responses were determined for several workplace visual stimuli which are temporally modulated at rates exceeding the perceptual critical fusion frequency (CFF). A clearly identifiable synchronous response was in evidence for a video display terminal (VDT) stimulus operating with a refresh rate as high as 76 Hz. A directly viewed fluorescent luminaire with controllable driving frequency elicited a synchronous response at rates as high as 145 Hz. In addition, an intense stimulus created by modulating the light from a slide projector produced responses at least as high as 162 Hz. The implications of these high-frequency responses as representing a potential basis for visual symptoms are discussed.%B Journal of Optometry and Vision Science %V 68 %P 645-662 %G eng %L LBL-24666 %1
Lighting Systems Group%2 LBL-24666 %0 Conference Paper %B Annual IES Conference %D 1988 %T Improving the Performance of Photo-Electrically Controlled Lighting Systems %A Francis M. Rubinstein %A Gregory J. Ward %A Rudolph R. Verderber %X
The ability of a photo-electrically controlled lighting system to maintain a constant total lightslevel on a task surface by responding to changing daylight levels is affected by the controlsalgorithm used to relate the photosensor signal to the supplied electric light level and by thesplacement and geometry of the photosensor. We describe the major components of astypical control system, discuss the operation of three different control algorithms, andsderive expressions for each algorithm that express the total illuminance at the task as asfunction of the control photosensor signal. Using a specially designed scale model, wesmeasured the relationship between the signal generated by various ceiling-mounted controlsphotosensors and workplane illuminance for two room geometries under real skysconditions. The measured data were used to determine the performance of systemssobeying the three control algorithms under varying daylight conditions. Control systemssemploying the commonly-used integral reset algorithm supplied less electric light thansrequired, failing to satisfy the control objective regardless of the control photosensor used.sSystems employing an alternative, closed-loop proportional control algorithm achieved thescontrol objective under virtually all tested conditions when operated by a ceiling-mountedsphotosensor shielded from direct window light.%B Annual IES Conference %C Minneapolis, MN %8 08/1988 %G eng %L LBL-24871 %1
Lighting Systems Group%2 LBL-24871 %0 Conference Paper %B IEEE-IAS Annual Conference %D 1988 %T Performance of Electronic Ballast and Controls with 34 and 40 Watt F40 Fluorescent Lamps %A Rudolph R. Verderber %A Oliver C. Morse %A Francis M. Rubinstein %X
The electric and photometric characteristics have been compared for 40 watt (40W) and 34 watts (34W), F40 T-12 fluorescent lamps by operating them with electronic ballasts, static controls and dynamic controls of different designs. The energy savings krypton filled 34W lamp system is, at best, slightly more efficacious than the standard 40W argon filled lamp system by virtue of the use of lite white phosphor. The 34W system has limitations that include higher starting voltages, reduced temperature range of operation, smaller dimming range and poorer color rendering than the standard cool white 40W lamp system.%B IEEE-IAS Annual Conference %C Minneapolis, MN %8 10/1988 %G eng %L LBL-25429 %1
Lighting Systems Group%2 LBL-25429 %0 Journal Article %J Computer Graphics %D 1988 %T A Ray Tracing Solution for Diffuse Interreflection %A Gregory J. Ward %A Francis M. Rubinstein %A Robert D. Clear %X
An efficient ray tracing method is presented for calculating interreflections between surfaces with both diffuse and specular components. A Monte Carlo technique computes the indirect contribution sto illuminance at locations chosen by the rendering process. The indirect illuminance values are averaged over surfaces and used in place of a constant ambient term. Illuminance calculations are made only for those areas participating in the selected view, and the results are stored so that subsequent views can reuse common values. The density of the calculation is adjusted to maintain a constant accuracy, permitting less populated portions of the scene to be computed quickly. Successive reflections use proportionally fewer samples, which speeds the process and provides a natural limit to recursion. The technique can also model diffuse transmission and illumination from large area sources, such as the sky.%B Computer Graphics %V 22 %G eng %L LBL-22789 %1
Lighting Systems Group%2 LBL-22789 %0 Journal Article %J Building and Environment %D 1988 %T Residential cooling loads and the urban heat island—the effects of albedo %A Haider Taha %A Hashem Akbari %A Arthur H. Rosenfeld %A Yu Joe Huang %K Heat Island %K urban heat island %X
The urban heat island has become the target of recent research aiming at improving urban climates and energy efficiency of cities. In the warm, mid- and low-latitude cities, the typical heat island intensity averages up to 3-5°C on a summer day, adding to discomfort and increasing the air-conditioning loads, whereas in some temperate and cold, high-latitude cities a 2°C heat island is considered as a mild asset in winter. Some of these cities have been built to retain the urban heat. The objective of our ongoing research is to identify ways to mitigate summer heat islands in hot climates, for example by increasing the urban albedo, expanding evaporative surfaces and vegetation covers, and increasing urban thermal mass. From the energy consumption point of view, simple techniques such as these can be effective in reducing air-conditioning costs by modifying and improving the urban micro- and meso-climates. In this work, we have correlated the residential cooling energy and power consumption in Sacramento, California, with the urban heat island intensity. The effects of selected strategies, such as the ones mentioned above, upon changing the urban micro-climate and reducing the heat island induced cooling loads were simulated. The main focus in this paper is placed on albedo. The simulations were performed using the DOE-2.1C building energy analysis program in conjunction with micro-climate and planetary boundary layer models that predict the effects of albedo modifications on ambient conditions and micro-climates. The simulations indicate that there exists significant potential energy and peak power savings by using such simple conservation strategies. Simulations for Sacramento indicate that whitewashing the buildings can result in direct savings of up to 14% and 19% on cooling peak power and electrical cooling energy, respectively. Modifying the overall urban albedo, in addition to whitewashing, can result in total savings of up to 35% and 62% respectively.%B Building and Environment %V 23 %P 271-283 %G eng %R 10.1016/0360-1323(88)90033-9 %0 Conference Paper %B 13th National Passive Solar Conference %D 1988 %T WINDOW 3.1: A Computer Tool for Analyzing Window Thermal Performance %A M. Susan Reilly %A Dariush K. Arasteh %B 13th National Passive Solar Conference %C Cambridge, MA %8 06/1988 %G eng %L LBL-25148 %1
Windows and Daylighting Group%2 LBL-25148 %0 Report %D 1988 %T WINDOW 3.1: A PC Program for Analyzing Window Thermal Performance (Program Disk and Tutorial) %A Dariush K. Arasteh %A M. Susan Reilly %G eng %L LBL-25686 %1
Windows and Daylighting Group%2 LBL-25686 %0 Journal Article %J International Communications in Heat and Mass Transfer %D 1987 %T A Correlation Between Normal and Hemispherical Emissivity of Low-Emittance Coatings on Glass %A Michael D. Rubin %A Dariush K. Arasteh %A John Hartmann %X
Transparent low-emissivity coatings are commonly used to reduce the thermal conductance of windows. It is important to be able to characterize and compare the wide variety of these coatings that are now available. The property that best describes the effectiveness of a coating in suppressing radiative heat transfer is the total hemispherical emissivity. It is much simpler, however, to measure the normal emissivity. This paper shows that a correspondence exists between these two properties which applies to most types of low-emissivity composite coatings. An empirical expression for this correspondence is provided.%B International Communications in Heat and Mass Transfer %V 14 %P 561-565 %G eng %1
Windows and Daylighting Group%2 LBL-23384 %0 Journal Article %J ASHRAE Transactions %D 1987 %T Experimental Verification of a Model of Heat Transfer Through Windows %A Dariush K. Arasteh %A John Hartmann %A Michael D. Rubin %X
A procedure has been developed for calculating the one-dimensional heat flux through complex window systems. A computer program embodying this procedure (WINDOW 2.0) is available to the public. The window may consist of multiple glass or plastic layers, separated by gas-filled spaces. Gases other than air may fill the space between solid layers, and the layers may have low-emissivity coatings. Measurements from five different manufacturers and researchers of the overall thermal conductance of various window systems confirm the validity of this model for a range of temperatures and layer spacings less than 3 cm (1.2 in). A list of U-values and shading coefficients is given for a representative group of windows.%B ASHRAE Transactions %V 93 %G eng %L LBL-21576 %1
Windows and Daylighting Group%2 LBL-21576 %0 Conference Paper %B 1987 IES National Conference %D 1987 %T Measurement of Optical Efficiency of Fluorescent Luminaires %A Rudolph R. Verderber %A Oliver C. Morse %A Francis M. Rubinstein %A Michael J. Siminovitch %X
By controlling the lamp wall temperature of fluorescent lamps with a Peltier device, the optical efficiency of luminaires can be measured directly. Measurements of the fixture efficiency for a luminaire can vary by over 8% depending upon the lamp-ballast system used in the measurement. The authors suggest that optical efficiency may besan improved metric for evaluating fixture designs.%B 1987 IES National Conference %C Scottsdale, AZ %8 08/1987 %G eng %L LBL-23169 %1
Lighting Systems Group%2 LBL-23169 %0 Journal Article %J Journal of the Illuminating Engineering Society %D 1987 %T A New Technique for Computer Simulation of Illuminated Spaces %A Gregory J. Ward %A Francis M. Rubinstein %X
An advanced ray-tracing technique for computing luminances in unempty spaces is presented. The method is a hybrid of finite element analysis and Monte Carlo techniques. Interreflection between specular surfaces of complex geometries can be computed to any desired accuracy. Applications to synthetic imaging for lighting design are highlighted.%B Journal of the Illuminating Engineering Society %V 17 %P 80-91 %G eng %L LBL-23042 %1
Lighting Systems Group%2 LBL-23042 %0 Journal Article %J Journal of Climate and Applied Meteorology %D 1987 %T The potential of vegetation in reducing summer cooling loads in residential buildings %A Hashem Akbari %A Yu Joe Huang %A Haider Taha %A Arthur H. Rosenfeld %X
The potential of trees and other vegetation to reduce building cooling loads has been recorded in a number of studies but the meso- and microclimate changes producing such savings are not well understood. This paper describes a preliminary attempt to model the effects of landscaping on temperature, humidity, windspeed and solar gain in urban climates using information from existing agricultural and meteorological studies, with particular attention placed on quantifying the effects of plant evapotranspiration. The climate model is then used in conjunction with the DOE-2.1C building simulation program to calculate the net reductions in air-conditioning requirements due to trees and other vegetation.
Preliminary results show that an additional 25% increase in the urban tree cover can save 40% of the annual cooling energy use of an average house in Sacramento, and 25% in Phoenix and Lake Charles. If this additional tree cover is located to optimize summer shading, the savings are further increased to more dun 50% in Sacramento and 33% in the other two cities. The calculated savings are minimal for Los Angeles because the base case cooling energy use is small (65 hours) on the assumption that window venting is used whenever possible in lieu of mechanical cooling. There are additional benefits in lowering peak power consumption, where the savings are as much as 34% in Sacramento, 18% in Phoenix, 22% in Lake Charles, and 44% in Los Angeles. Parametric analysis reveals that most of the savings can be attributed to the effects of increased plant evapotranspiration, and only 10% to 30% to shading. The energy penalties of reduced windspeeds are found to be small in all four locations.
The preliminary results suggest that while the conservation benefits of planting trees are appreciable at the individual house level, equally dramatic savings can be realized at the urban level through modifications of the urban climate by increasing the total amount of vegetative cover. Such a conservation strategy may be elective in counteracting the summer heat island evident in cities and may improve ambient conditions as well as reduce summertime air-conditioning requirements.%B Journal of Climate and Applied Meteorology %V 26 %P 1103-1116 %8 09/1987 %G eng %N 9 %& 1103 %R 10.1175/1520-0450(1987)026<1103:TPOVIR>2.0.CO;2 %0 Report %D 1987 %T Progress Report FY 1987: Development of TiN Low-E Coatings %A Michael D. Rubin %X
Titanium nitride (TiN) shows promise as a low-emittance coating for windows because it possesses both the optical properties of a metal and the hardness and inertness of a ceramic. Titanium dioxide (TiO2) is a convenient choice for a matching layer to enhance the solar transparency. TiN and TiO2 films have been deposited on glass by reactive dc magnetron sputtering, which is a standard technique used for production of window coatings. The composition of these films was determined by X-ray photoelectron spectroscopy (XPS). Incorporation of N and O appears to follow the Langmuir adsorption isotherm at low partial pressures. Structure was determined by x-ray diffraction, using both Seemann-Bohlin and conventional Bragg-type geometries. Nonequilibrium phase diagrams have been prepared from this information for various deposition conditions. The properties of these films depend strongly on the sputtering conditions, especially gas pressures, substrate temperature, and bias voltage. Emittance values have been achieved that are much lower than those of TiN films produced commercially. Multilayer coatings have been deposited with greatly improved spectral selectivity.%G eng %L LBL-24448 %1
Windows and Daylighting Group%2 LBL-24448 %0 Report %D 1987 %T Progress Report: Optical Properties of Thermochromic VO2 Coatings for Windows %A Michael D. Rubin %X
The properties of VO2, thermochromic coatings were investigated for application to building windows. The solar transmittance of VO2 decreases above a certain temperature, blocking excess solar gain. Films were deposited on glass by reactive magnetron sputtering, but stoichiometric compositions have not yet been achieved. The composition and structure of these films have been determined by Auger spectroscopy and x-ray diffraction. Optical properties were measured by photometric and ellipsometric methods. Using this optical data, composite coatings were designed having improved optical characteristics. The high-temperature metallic state of VO2 was not found to be suitable as a static low-emissivity coating. When this VO2, is used as a thermochromic coating, however, its moderately low-emissivity would contribute to energy savings. The ratio of solar transmittance between the high-temperature and low-temperature states increases with decreasing average transmittance. Higher values of this ratio might be obtained by proper choice of additional coating layers.%G eng %1
Windows and Daylighting Group%2 LBL-22707 %0 Conference Paper %B 12th National Passive Solar Conference %D 1987 %T Thermal and Solar-Optical Properties of Silica Aerogel for Use in Insulated Windows %A John Hartmann %A Michael D. Rubin %A Dariush K. Arasteh %X
Silica aerogel is a porous insulating material that is transparent to solar radiation. To understand its insulating performance in a window system, it is necessary to first study component heat transfer paths. Aerogels absorption coefficient, a measure of the attenuation of radiation heat transfer, was determined over the spectral range 1-200 µm. Although radiation heat transfer is negligible over much of this region, there is a transmission window between 3-6 pm. At ambient temperatures, for aerogel thicknesses of 0.5-5.0 cm, radiation heat transfer through an unmodified aerogel window is less than 15% of the total heat flux. For evacuated or high-temperature furnace windows, this contribution can be over 50%. Thermal radiative transfer can be somewhat decreased by allowing the aerogel to absorb moisture, but solar transmission and optical clarity are sacrificed. Absorption of water vapor over time causes irreversible structural changes that increase scattering in the solar spectrum. Aerogels thermal performance can be improved by replacing the pore gas with one of lower conductivity or by evacuating the aerogel to pressures below 0.1 atm. A hypothetical evacuated aerogel window has a calculated UValue of ≈ 0.5 W/m2-K for a gap spacing of 12.5 mm, which is four times better than currently available low-emissivity gas-filled units of similar size.%B 12th National Passive Solar Conference %C Portland, OR %G eng %L LBL-23386 %1
Windows and Daylighting Group%2 LBL-23386 %0 Journal Article %J Journal of Quantitative Spectroscopy and Radiation Transfer %D 1986 %T Determination of the Excited State Density of an Optically Thick Line %A Sam M. Berman %A Robert W. Richardson %X
The transverse profile of the monochromatic radiance of an optically thick resonance line from a cylindrical discharge is inverted exactly to give the radial distribution of radiating atoms. In contrast to the Abel transform, this result is valid for all optical depths.%B Journal of Quantitative Spectroscopy and Radiation Transfer %V 37 %P 471-475 %G eng %L LBL-21475 %1
Lighting Systems Group%2 LBL-21475 %0 Conference Paper %B 1986 International Daylighting Conference %D 1986 %T The Effect of Control Algorithm Photosensor Response on the Performance of Daylight Linked Lighting Systems %A Francis M. Rubinstein %A Gregory J. Ward %A Rudolph R. Verderber %X
Increased utilization of daylighting in commercial buildings is one method of reducing the requirement for daytime lighting energy and for moderating peak demand. For daylight to efficiently supply some portion of the design light level at the task, the electric lighting system should be photo-electrically controlled so that it responds (dims) in proportion to the amount of available daylight entering the building space. The location and spatial response of the photosensor that controls the electric lighting system must be chosen so that the photosensors output is approximately proportional to the illumination at the task surface. Furthermore, the systems control algorithm, which relates the photosensor signal to the output of the electric lights, should be selected to properly account for the location of the control photosensor relative to the task and the sources of illumination within the controlled space. If the above considerations are not properly accounted for, then the illumination at the task will deviate significantly from the design level (Rubinstein 1984) and the occupants may respond negatively, especially if the control system supplies less than the design light level.
The paper describes experimental work done to analyze how the control algorithm and the photosensors location and spatial response affect the ability of a daylight-following lighting system to maintain a constant light level at the task by responding to changes in daylight levels.%B 1986 International Daylighting Conference %C Los Angeles, CA %8 11/1986 %G eng %L LBL-20562 %1
Lighting Systems Group%2 LBL-20562 %0 Conference Paper %B 1986 IEEE-IAS National Conference %D 1986 %T The Effect of Lighting System Components on Lighting Quality, Energy Use, and Life-Cycle Cost %A Francis M. Rubinstein %A T. Alan Clark %A Michael J. Siminovitch %A Rudolph R. Verderber %X
A computational method was developed to examinesthe effect of lamp, ballast, and fixture selection on the quality andsquantity of illumination, energy consumption, and life-cycle cost ofslighting systems. Applying this analysis to lighting layouts usingsdifferent lamp/ballast/fixture combinations suggested thatscombinations with higher lumen outputs reduced the uniformity ofsthe illuminance distribution at the workplane but did not reducesvisibility levels. The use of higher lumen output lamp/ballast/fixturessystems and higher efficiency components tended to reduce life-cyclescosts as long as the premium cost of the components was notstoo high.%B 1986 IEEE-IAS National Conference %C Denver, CO %8 10/1986 %G eng %L LBL-21884 %1
Lighting Systems Group%2 LBL-21884 %0 Conference Paper %B 1986 IEEE-IAS National Conference %D 1986 %T The Effects of Fixture Type and HVAC Integration on Fluorescent Lamp-Ballast Performance %A T. Alan Clark %A Francis M. Rubinstein %A Michael J. Siminovitch %A Rudolph R. Verderber %X
This paper describes the effects of fixture type and lamp compartment air extract characteristics on lamp/ballast performance.
A luminaire/plenum/HVAC simulator was used to measure minimum lamp wall temperature inside four fixture types while varying lamp-compartment extract conditions. Experimental data show that the lumen output of the lamp/ballast system varies by 20% and system efficacy by 10%, depending on the type of fixture and lamp compartment extract technique employed.%B 1986 IEEE-IAS National Conference %C Denver, CO %8 10/1986 %G eng %1
Lighting Systems Group%2 LBL-21775 %0 Conference Paper %B International Daylighting Conference Proceedings %D 1986 %T The Integration of Operable Shading Systems and Lighting Controls %A Konstantinos M. Papamichael %A Francis M. Rubinstein %A Stephen E. Selkowitz %A Gregory J. Ward %X
Using daylighting in commercial buildings may significantly reduce electric lighting requirements if appropriatesphotoelectric controls are used to adjust the electric lighting output according to the available daylight. Prior analysis andsresults from monitored buildings and scale-model measurements suggest that the selection, placement, and installation ofsthe control photosensor is a difficult task, even with simple non-operable fenestration systems, since the daylightscontributions from sun, sky, and ground change continuously. The problem becomes even more complex forsfenestration systems that incorporate operable shading devices, because every adjustment changes the systems opticalsproperties. This paper presents results from measurements in a scale model under real skies, designed to bettersunderstand the problem of integrating fenestration and lighting controls. The scale model represented a typical officesspace and was equipped with motorized venetian blinds. Three control photosensors mounted on the ceiling weresconsidered for the operation of the electric lighting system, and two control strategies were considered for the operation ofsthe venetian blinds. Two ground-plane reflectances and two window orientations were examined. Results indicate thatsthe signal from a ceiling-mounted control photosensor shielded from direct light from the window shows the bestscorrelation with daylight work-plane illuminance, regardless of ground plane reflectance or venetian blind slat angle for allsslat angles that do not allow penetration of direct solar radiation. Results also indicate that the control strategies of thesvenetian blinds that were considered for the purposes of this study may result in significantly different slat angles, andsthus different daylighting work-plane illuminances and electric lighting requirements, especially when the ground-planesreflectance is high.%B International Daylighting Conference Proceedings %C Long Beach, CA %8 11/1986 %G eng %L LBL-20536 %1
Windows and Daylighting Group%2 LBL-20536 %0 Journal Article %J Journal of the Illuminating Engineering Society %D 1986 %T Magnetic Enhancement of Ultraviolet Radiation Efficiency of Low Pressure Hg-Ar Discharge %A T. Zhou %A L. Wang %A Donald D. Hollister %A Sam M. Berman %A Robert W. Richardson %B Journal of the Illuminating Engineering Society %V 16 %P 176-181 %8 07/1986 %G eng %N 1 %1
Lighting Systems Group%2 LBL-22360 %& 176 %R 10.1080/00994480.1987.10748677 %0 Journal Article %J Lighting Design + Application %D 1986 %T Maintaining Optimum Fluorescent Lamp Performance Under Elevated Temperature Conditions %A T. Alan Clark %A Francis M. Rubinstein %A Michael J. Siminovitch %A Rudolph R. Verderber %X
This paper describes a new technique for optimizing fluorescent lamp performance underselevated temperature conditions. This approach uses a thermo-electric Peltier device tosproduce a localized cold spot temperature of approximately 40°C, allowing the lamps tosmaintain maximum light output and efficacy independent of prevailing ambient temperaturessinside a luminaire.
Experimental data shows that a 20% increase in light output and a 10% increase insefficacy over typical lamp performance in a warm fixture environment can be obtained usingsthis device. Only 0.25 watts must be supplied to the Peltier device to produce these results.%B Lighting Design + Application %V 17 %P 35-41 %8 04/1986 %G eng %1
Lighting Systems Group%2 LBL-21004 %0 Journal Article %J ASHRAE Transactions %D 1986 %T Thermal Analysis of Buildings - Configuration Perturbations and Observed Climate Interface %A Robert Sullivan %A Yu Joe Huang %A James Bull %A Isaac Turiel %A Ronald L. Ritschard %A Stephen E. Selkowitz %X
Results are presented that indicate a proportional relationship between building thermal loads for varying configuration parameters. Through the use of numerous building energy simulations using both the DOE-2.1 and BLAST energy analysis computer programs, it is shown that the relationship is independent of climatic location and covers a broad spectrum of those variables that influence a buildings energy use. The theoretical justification associated with such a phenomenon is treated using a multiple regression-derived algebraic expression that clearly establishes the linear independence of a buildings heat gain/loss components. Procedures are defined for the simplification of future parametric studies of the thermal analysis of buildings using a methodology that incorporates the observations reported herein.%B ASHRAE Transactions %V 92 %8 04/1985 %G eng %1
Windows and Daylighting Group%2 LBL-19383 %0 Report %D 1985 %T Building Energy Retrofit Research: Multifamily Sector %A Richard C. Diamond %A Charles A. Goldman %A Mark P. Modera %A Michael H. Rothkopf %A Max H. Sherman %A Edward L. Vine %I U.S. Department of Energy %C Washington DC %8 1985 %G eng %0 Report %D 1985 %T Commercial-Sector Conservation Technologies %A Russell Johnson %A Glenn Sweitzer %A Francis M. Rubinstein %A Dariush K. Arasteh %G eng %L LBL-18543 %1
Windows and Daylighting Group%2 LBL-18543 %0 Report %D 1985 %T CONTROLITE 1.0 Lighting Control Systems and Daylighting Analysis Program: User's Manual %A Lighting Systems Research %X
This users manual explains how to work with the CONTROLITE lighting control system analysis program on your IBM Personal Computer. It contains:
The CONTROLITE manual assumes that you have read and are familiar with the IBM Personal Computer Guide to Operations, Section 2 in particular.%I Lawrence Berkeley Laboratory %C Berkeley, CA %8 01/1985 %2 LBL-17444 Rev. %0 Journal Article %J Journal of the Illuminating Engineering Society %D 1985 %T Determination of Optimum Sector Size for Automatic Lighting Controls %A Francis M. Rubinstein %A Rudolph R. Verderber %A Mahmut Karayel %X
Automatic lighting controls can significantly reduce operating costs in commercial buildings. However, the design of these dynamically operated lighting systems has not kept pace with advancements in equipment. This paper focuses on determining how many lights should be grouped into sectors and controlled as a unit in order to minimize the life-cycle cost of an automatically controlled lighting system. The analysis is based on occupant behavior patterns, the cost of the lighting controls, the energy costs, and a decision criterion based on life-cycle cost.
Occupant switching patterns in the morning and afternoon were experimentally determined at a lighting control demonstration at the World Trade Center (WTC) building in New York City. The experimental procedure used to estimate the occupancy probability distributions at the WTC site is described in section 2. Section 3 develops a general analytical model for determining how large to make independently controlled lighting sectors in order to most cost-effectively use the scheduling control strategy. In Section 4, the model is applied to the occupant behavior patterns measured at the WTC site. Section 5 discusses the significance of the results; the final section summarizes the study.%B Journal of the Illuminating Engineering Society %V 15 %P 19-Mar %G eng %L LBL-19474 %1
Lighting Systems Group%2 LBL-19474 %0 Conference Paper %B Annual IEEE-IAS Conference %D 1985 %T Effect of Filament Power Removal on a Fluorescent Lamp System %A Rudolph R. Verderber %A Oliver C. Morse %A Francis M. Rubinstein %X
Two techniques are used to measure the effect of removing the filament power from a two-lamp, F-40, rapid-start fluorescent lamp system. The changes are measured for a standard CBM core-coil ballast and for a solid-state ballast operating the lamp at high frequency. There is a 4 to 6% increase in system efficacy when the filament power is removed. Removal of filament power also decreases filament temperature from 1000 °C below 700 °C in lamps operated at 60 Hz, and from above 600 °C to 300 °C in lamps operated at high frequency. The study shows that the arc current and anode fall also determine filament temperature.%B Annual IEEE-IAS Conference %C Toronto, Canada %8 10/1985 %G eng %L LBL-19779 %1
Lighting Systems Group%2 LBL-19779 %0 Report %D 1985 %T Electrodeless HID Lamp Study: Final Report %A John M. Anderson %A Peter D. Johnson %A C. E. Jones %A Theodore H. Rautenberg %X
High intensity discharge lamps excited by solenoidal electric fields (SEF/HID) were examinedsfor their ability to give high brightness, high efficacy and good color. Frequencysof operation was 13.56 MHz (ISM Band) and power to the lamp plasma ranged fromsabout 400 to 1000 W. Radio frequency transformers with air cores and with air core complementedsby ferrite material in the magnetic path were used to provide the voltage forsexcitation. Electrical properties of the matching network and the lamp plasma were measuredsor calculated and total light from the lamp was measured by an integrating sphere.sEfficacies calculated from measurement were found to agree well with the positive columnsefficacies of conventional HID lamps containing only mercury, and with additives of sodium,sthallium, and scandium iodide. Recommendations for future work are given.%G eng %L LBL-19035 %1
Lighting Systems Group%2 LBL-19035 %0 Conference Paper %B IEEE-IAS Annual Conference %D 1985 %T Fixture Conditions Affect Lamp Performance %A Michael J. Siminovitch %A Francis M. Rubinstein %A Rudolph R. Verderber %X
This article discusses the major parameters that affect fluorescent lamp performance under fixture conditions. These parameters include fixture type, and HVAC integration, which directly determine the minimum lamp wall temperature (MLWT), and therefore, the resulting light output of the lamp/ballast system. Experimental data is presented showing that the lumen output of the lamp/ballast system can vary by as much as 20% and that the system efficacy can vary by 10% depending upon the type of fixture and HVAC system employed.%B IEEE-IAS Annual Conference %C Toronto, Canada %8 10/1985 %G eng %L LBL-22531 %1
Lighting Systems Group%2 LBL-22531 %0 Conference Paper %B Annual IEEE-IAS Conference %D 1985 %T Life of Fluorescent Lamps Operated at High Frequencies with Solid-State Ballasts %A Rudolph R. Verderber %A Oliver C. Morse %A Francis M. Rubinstein %X
Standard 40-watt, F-40, rapid-start, fluorescentslamps were operated with solid-state ballasts followingsthe standard life-testing cycle of 3 hours on ands20 minutes off for more than 20,000 hours at highsfrequency. Lamp operating characteristics (starting voltage, filament voltage, arc current, and current-crest factor) were studied as factors affecting lampslife. Measurements show that fluorescent lamps can attain rated life at high frequency using solid-state ballasts. When lamps are operated in the dimmedsnode, full filament power is required to sustain lampslife. The rate of lamp lumen depreciation is dependentson the lamp loading and not the operating frequency.%B Annual IEEE-IAS Conference %C Toronto, Canada %8 10/1985 %G eng %L LBL-19778 %1
Lighting Systems Group%2 LBL-19778 %0 Conference Paper %B Annual IEEE-IAS Conference %D 1985 %T A Luminaire/Plenum/HVAC Simulator %A Michael J. Siminovitch %A Francis M. Rubinstein %A T. Alan Clark %A Rudolph R. Verderber %X
This paper describes a new apparatus designed to model the physical parameters that affect fluorescent lamp performance under realistic operating conditions. These parameters include fixture type, mounting configuration, HVAC integration, and room air temperature, which directly determine the minimum lamp wall temperature (MLWT) and, therefore, the resulting light output of the lamp/ballast system. This apparatus is used principally to measure MLWT under operating conditions, which enables us to identif sthe effects the major parameters have on lamp/ballast system performance. Initial parametric results illustrate the use of this apparatus to provide representative MLWTs for a range of application conditions.%B Annual IEEE-IAS Conference %C Toronto, Canada %8 10/1985 %G eng %L LBL-19168 %1
Lighting Systems Group%2 LBL-19168 %0 Journal Article %J Solar Energy Materials %D 1985 %T Optical Constants and Bulk Optical Properties of Soda Lime Silica Glasses for Windows %A Michael D. Rubin %X
A comprehensive set of optical constants and a partial set of bulk optical properties are listed for clear, absorbing, and low-iron glasses used for windows. The measurements extend from the near ultraviolet to the far infrared, covering the range of interest for calculating solar and thermal radiative transfer through windows. This information is also needed to calculate the properties of thin-film coatings on glass substrates. Large variations in solar absorption are observed among these glasses, whereas the far-infrared properties are almost constant for all glass types. An important quantity, the hemispherical total emissivity, is 0.837 at 20 degrees C, as determined from reflectance data measured with an IBM Fourier-transform spectrometer. Solar properties are determined from conventional transmission and reflection measurements.%B Solar Energy Materials %V 12 %P 275-288 %G eng %L LBL-13572 %1
Windows and Daylighting Group%2 LBL-13572 %0 Conference Paper %B 9th Passive and Hybrid Solar Energy Update %D 1984 %T Advanced Optical and Thermal Technologies for Aperture Control %A Stephen E. Selkowitz %A Arlon J. Hunt %A Carl M Lampert %A Michael D. Rubin %X
Control of heat transfer and radiant energy flow through building apertures is essential for maximizing thermal and daylighting benefits and minimizing undesired heating and cooling loads. Architectural solutions based on current technology generally add devices such as louvers, shutters, shades, or blinds to the glazing system. This paper outlines the objectives and accomplishments of a research program the goal of which is to identify and evaluate advanced optical and thermal technologies for controlling aperture energy flows, thus reducing building energy requirements. We describe activities in four program areas:
Windows and Daylighting Group%2 LBL-18607 %0 Conference Paper %B IEEE-IAS Annual Meeting %D 1984 %T The Control of Daylight-Linked Lighting Systems %A Francis M. Rubinstein %A Gregory J. Ward %X
This paper describes the components of a daylight-linked lighting system and presents three simple control algorithms that can be incorporated into a control system to achieve the design objective of constant task illuminance.%B IEEE-IAS Annual Meeting %C Chicago, IL %8 09/1984 %G eng %L LBL-18065 %1
Lighting Systems Group%2 LBL-18065 %0 Report %D 1984 %T CONTROLITE 1.0: Program Documentation %A Lighting Systems Research %X
In theory, a lighting control system which continuously monitors the available artificial and natural light within a space and supplies only the power required to provide light to meet some specified criteria illuminance level, and no more, should be able to optimize the energy savings capabilities of that lighting control system. Because of the potential for constantly varying power consumption due to this Equi-Illumination Dimming (EID) system, the computer is employed to help in modeling these types of systems.
This computer program, CONTROLITE, provides an unbiased mathematical model from which comparisons can be made, on an economic basis only, of how different systems perform. The program has the option of calculating daylighting values, or allowing the user to specify the daylighting values as input. Calculations can also be done o~ simple control systems which do not respond to daylighting.
For purposes of allowing for the calculating of daylighting values, program CONTROLITE is augmented with an accurate yet quick subprogram QUICKLITE. QUICKLITE employs what is known as the daylight factor method for calculation of daylighting values. The procedure which is used by QUICKLITE is well documented, and it is recommended that the user consult the references in Appendix B for this documentation.
The CONTROLITE program analyses control schemes exclusively on an economic basis, considering only the energy consumed directly by the lighting system. No attempt has been made to account for any additional savings realized in HVAC systems when lighting systems are controlled. The program makes no statement about the user acceptance of lighting control systems or about the aesthetic qualities of the use of daylighting within interior spaces.
The major components of the program are discussed in this documentation and several examples are included to explain how to run the program.%I Lawrence Berkeley Laboratory %C Berkeley %8 03/1984 %G eng %1
Lighting Systems Group%2 LBL-17444 %0 Journal Article %J Journal of the Illuminating Engineering Society %D 1984 %T Determining Lamp/Ballast System Performance with a Temperature Controlled Integrating Chamber %A Michael J. Siminovitch %A Francis M. Rubinstein %A Rudolph R. Verderber %X
This paper describes an experimental integrating chamber for measuring the photometric and electrical performance of fluorescent light sources over a wide range of bulb-wall temperatures. The system was used to measure the relative light output and system efficacy of various solid-state ballasted fluorescent lighting systems for minimum bulb-wall temperatures between 20 degrees and 65 degrees C. For lamp-wall temperatures between 30 and 60 degrees C, the relative efficacies of the solid-state ballasted systems were found to be less sensitive to changes in bulb-wall temperatures than standard or efficient (low-loss) core-coil ballasted systems.%B Journal of the Illuminating Engineering Society %V 14 %P 364-378 %G eng %L LBL-17285 %1
Lighting Systems Group%2 LBL-17285 %0 Report %D 1984 %T An Experimental Methodology for Determining the System Performance of Fluorescent Lamp, Ballast, Fixture Combinations Operating Under Realistic Application Conditions %A Michael J. Siminovitch %A Francis M. Rubinstein %A Rudolph R. Verderber %X
Designers who wish to compare and select lighting systems and to design lighting layouts that meet both illuminance and energy code requirements require accurate data documenting the combined performance capabilities of fluorescent lamp, ballast, and fixture systems operating under realistic application conditions. These application conditions may differ significantly from the standard ANSI conditions under which routine photometric tests are performed, introducing temperature-dependent errors into the lighting design calculation procedure.
To meet the need for accurate performance data, we plan to develop and demonstrate an experimental method for determining the performance of lamp, ballast, and luminaire combinations operating under a broad range of realistic conditions.%G eng %L LBL-18683 %1
Lighting Systems Group%2 LBL-18683 %0 Conference Paper %B National Research Council of Canadas Lighting Control Symposium %D 1984 %T Lighting Controls: The Role of Advanced Technology--Past, Present, and Future %A Rudolph R. Verderber %A Francis M. Rubinstein %X
The role of technology in the development of lighting control systems is examined. Prior to 1973, control systems were primarily functional. They were used to switch lamps on and off, or to create a mood. Nearly all dimming was done with incandescent lamps.
Since 1973, the rising cost of electrical energy has made the operational cost of systems a design factor. Lighting controls are used to decrease power, reduce the time of use, and lower peak power demands. New lighting control equipment is based on existing technologies that have been modified to meet the needs of lighting systems. The technologies came primarily from the field of electronics.
These developments have made it technically feasible to automatically control the intensity and distribution of lighting in an area illuminated by a single fixture. These technologies form the basis for meeting future goals of lighting designs to alter illumination levels over time.%B National Research Council of Canadas Lighting Control Symposium %C Ottawa, Canada %8 06/1984 %G eng %L LBL-17967 %1
Lighting Systems Group%2 LBL-17967 %0 Conference Paper %B 1984 ACEES Summer Study %D 1984 %T New Lighting Technologies, Their Status and Impacts on Power Densities %A Rudolph R. Verderber %A Francis M. Rubinstein %X
There have been many new lighting products introduced since the 1973 energy crises. The products that entered the market most rapidly were based on existing technologies and relied primarily on reducing light levels to reduce electrical power use. These systems worked for retrofitting existing spaces that were over-illuminated. In the mid-70s, new products employing new technologies were developed that increased the efficacy of producing and distributing visible light. These included the high-frequency operation of fluorescent lamps, replacement of incandescent light sources, and effective management of lighting. These technologies will be described and their present status, with regard to their current use, will be discussed. Their impacts on energy use and on the quantity and quality of illumination will be presented. The results will provide evidence that proposed lighting power densities of 1.5 watts per square foot for lighting can be realized.%B 1984 ACEES Summer Study %C Santa Cruz, CA %8 08/1984 %G eng %L LBL-18114 %1
Lighting Systems Group%2 LBL-18114 %0 Journal Article %J IEEE Transactions on Industry Applications %D 1983 %T Comparison of Technologies for New Energy-Efficient Lamps %A Rudolph R. Verderber %A Francis M. Rubinstein %X
Energy-efficient light bulbs are being developed to replace the incandescent lamp where they can satisfy the design criteria and be used in sockets that have long hours of annual use. The four technologies discussed here include the compact fluorescent lamp, coated-filament lamp, electrodeless fluorescent lamp, and compact high-intensity discharge lamp. The systems demonstrate efficacy improvements of two to four times that of their incandescent counterparts. These new lamps have required considerable advances in lamp technology. They offer the potential for achieving efficacies close to 80 lumens per watt.
These new lamps will reduce the energy used annually by incandescent lamps (190 BkWh) by more than 50% in the 1990s, at which times they will be commonly employed.%B IEEE Transactions on Industry Applications %V 1A-20 %G eng %L LBL-16225 %1
Lighting Systems Group%2 LBL-16225 %0 Report %D 1983 %T Energy-Efficient H.I.D. Solid-State Ballast: Phase II Final Report %A Lighting Systems Research %X
The following report presents the results of Phase II, Development of Solid State 150 watt High Pressure Sodium Ballasts. Basically, the objectives of the development program were accomplished, i.e., greater than 90% efficiency, greater than 90% power factor, regulation equivalent to ferro-magnetic ballasts, and energy savings sufficient to warrant the further development of the solid-state HPS ballast for commercial production and marketing.%I Lawrence Berkeley Laboratory %C Berkeley, CA %8 06/1983 %G eng %1
Lighting Systems Group%2 LBL-19860 %0 Conference Paper %B 3rd International Symposium on the Science and Technology of Light Sources %D 1983 %T Experimental Studies of Enhanced Emittance by Zeeman Splitting of a Low-Pressure Mercury/Argon Discharge %A Robert W. Richardson %A Sam M. Berman %B 3rd International Symposium on the Science and Technology of Light Sources %C Toulouse, France %8 04/1983 %G eng %L LBL-17394 %1
Lighting Systems Group%2 LBL-17394 %0 Journal Article %J Lighting Design + Application %D 1983 %T Field Study on Occupancy Scheduling as a Lighting Management Strategy %A Francis M. Rubinstein %A Mahmut Karayel %A Rudolph R. Verderber %X
Experimental results from a major demonstration of an advanced lighting energy management system at the World Trade Center are presented. The energy-saving benefits of automatically scheduling the operation of the lighting system to conform to occupancy patterns are examined. The energy saved by scheduling was measured by comparing lighting energy consumption without scheduling to consumption with scheduling. The benefits of a variety of switching scheduling are compared and the relationship between energy savings and sector size discussed. Using a loose automatic schedule with 1000 ft2 zones, lighting energy consumption was reduced by 30% relative to baseline consumption. With a tighter schedule, energy consumption was reduced 36-37%. Based on a simple economic analysis, scheduling is shown to be a cost-effective strategy for reducing energy consumption in buildings.%B Lighting Design + Application %V 14 %G eng %L LBL-15382 %1
Lighting Systems Group%2 LBL-15382 %0 Journal Article %J Energy and Buildings %D 1983 %T Mutual Impacts of Lighting Controls on Daylighting Applications %A Francis M. Rubinstein %A Rudolph R. Verderber %B Energy and Buildings %V 6 %P 133-140 %G eng %L LBL-15627 %1
Lighting Systems Group%2 LBL-15627 %0 Journal Article %J Energy and Buildings %D 1983 %T Photo-Electric Control of Equi-Illumination Lighting Systems %A Francis M. Rubinstein %X
A complete analysis of the cost-effectiveness of daylighting strategies should include the impact of daylighting on peak electrical demand as well as on energy consumption. We utilized an hour-by-hour building energy analysis program to study the thermal and daylighting impacts of fenestration on peak demand. Fenestration properties and lighting system characteristics were varied parametrically for office buildings in Madison WI and Lake Charles LA. Peak electrical demand was disaggregated by component and by zone, monthly patterns of peak demand were examined, and impacts of fenestration performance on chiller size were studied. The results suggest that for daylighted office buildings, the peak electrical demand results from a complex trade-off between cooling load due to fenestration parameters, lighting load reductions due to glazing and lighting system characteristics. Lowest peak demands generally occur with small to moderate size apertures. With daylighting, peak electrical demand is reduced by 10 to 20% for the building configuration studied (37% perimeter zone, 63% core zone). This work indicates that solar gain through fenestration must be effectively controlled in order to realize the potential of daylighting to significantly reduce peak electrical demand.%B Energy and Buildings %V 6 %P 141-150 %G eng %L LBL-15631 %1
Lighting Systems Group%2 LBL-15631 %0 Journal Article %J Solar Energy Materials %D 1983 %T Transparent Silica Aerogels for Window Insulation %A Michael D. Rubin %A Carl M Lampert %X
Supercritically drying a colloidal gel of silica produces a porous material called an aerogel. These aerogels not only are excellent thermal insulators, but also can be highly transparent. We investigate the microstructure and optical properties of transparent silica aerogels and calculate the energy transfer through hypothetical aerogel windows.%B Solar Energy Materials %V 7 %P 393-400 %G eng %L LBL-14462 %1
Windows and Daylighting Group%2 LBL-14462 %0 Conference Paper %B Passive and Hybrid Solar Energy Update %D 1982 %T Advanced Optical and Thermal Technologies for Aperature Control %A Stephen E. Selkowitz %A Carl M Lampert %A Michael D. Rubin %X
Control of heat transfer and radiant energy flow through building apertures is essential for maximizing thermal and daylighting benefits and minimizing undesired heating and cooling loads. Architectural solutions based on current technology generally add devices such as louvers, shutters, shades, or blinds to the glazing system. This paper outlines the objectives and initial accomplishments of a research program the goal of which is to identify and evaluate advanced optical and thermal technologies for controlling aperture energy flows, thus reducing building energy requirements. We describe activities in four program areas:
Windows and Daylighting Group%2 LBL-15131 %0 Journal Article %J Lighting Design + Application %D 1982 %T Energy Savings Through Effective Lighting Control %A David Peterson %A Francis M. Rubinstein %X
Lighting is one of the largest energy loads in a large commercial building. Lighting typically accounts for 35-50% of the electrical consumption which, in turn, dominates the total energy costs in a building. Since Edisons day, there has been a 100-fold increase in the efficacy of lighting sources. Relatively little progress, however, has been made in reducing consumption through effective lighting management — using the optimal amount of light, where needed, and when needed.
Commercial lighting control is an area where the potential for major energy saving exists. A number of new products have begun to emerge which focus on lighting control. To identify promising technologies and to expedite their adoption by building owners, the Department of Energy funded a program by Lawrence Berkeley Laboratory to test new, commercially available lighting controls in an actual office environment. The tests were designed to demonstrate the following:
Lighting Systems Group%2 LBL-14201 %0 Journal Article %J Solar Energy Materials %D 1982 %T Infrared Properties of Polyethylene Terephthalate Films %A Michael D. Rubin %X
The infrared radiation properties of polyethylene terephthalate films are calculated from the optical constants. Hemispherical total transmittance and emittance are given as functions of thickness. The difference between these properties and those of glass will significantly affect the thermal conductance of windows or solar collector covers.%B Solar Energy Materials %V 6 %P 375-380 %G eng %L LBL-13374 %1
Windows and Daylighting Group%2 LBL-13374 %0 Conference Paper %B IEEE-IAS Transactions %D 1982 %T The Measured Energy Savings from Two Lighting Control Strategies %A Francis M. Rubinstein %A Mahmut Karayel %X
The energy-saving benefits of two lighting control strategies — scheduling and daylighting — were investigated at demonstration sites in two large commercial buildings. A continuously-dimmable lighting control system was installed at the Pacific, Gas & Electric Co. building in San Francisco and an on/off switching system was installed at the World Trade Center building in New York City. By automatically scheduling the operation of the lighting systems to conform with occupancy patterns, lighting energy consumption was reduced 10 to 40%. Several scheduling techniques were investigated and the influence of switching zone size on energy savings was examined. Using photo-electrically controlled lighting systems which switch or dim lighting in accordance with available daylight, the energy consumed for lighting in daylit areas was reduced 25 to 35%. The influence of clear and overcast conditions on the energy savings associated with daylight-linked controls is discussed.%B IEEE-IAS Transactions %V 1A-20(5) %P 1189-1197 %8 06/1982 %G eng %1
Lighting Systems Group%2 LBL-14651 %0 Journal Article %J International Journal of Energy Research %D 1982 %T Solar Optical Properties of Windows %A Michael D. Rubin %X
To properly calculate dynamic solar gain in buildings, one must know the optical properties of the window in detail. In this paper, we develop a complete set of calculation procedures for determining the solar transmittance, reflectance, and absorptance of a window composed of an arbitrary number of partially transparent layers. Any layer may have a thin-film multilayer coating, such as an anti-reflection coating for increasing solar transmittance, a solar control film for reducing solar heat gain, or a transparent heat-reflecting mirror for improving thermal resistance. The results of sample calculations are given over the range of incidence angles for conventional and advanced energy conserving window designs.%B International Journal of Energy Research %V 6 %P 123-133 %G eng %L LBL-12246 %1
Windows and Daylighting Group%2 LBL-12246 %0 Journal Article %J Int. J. Energy res. %D 1981 %T Calculating Heat Transfer Through Windows %A Michael D. Rubin %X
To calculate the energy performance of buildings, one must know the heat-transfer characteristics of the windows as functions of environmental variables, such as temperature and wind speed. Window designs are becoming more complex in response to the need for energy conservation. In this paper, we develop a general procedure for calculating the net energy flux through the glazed area of a window composed of an arbitrary number of solid layers. These layers, which may have thin-film coatings, can have any specified solar and thermal radiation properties and enclosed spaces between solid layers can contain either air or other gases. We verified our results by comparing them with experimental measurements of heat flow using a calibrated hot-box.%B Int. J. Energy res. %V 6 %P 341-349 %G eng %L LBL-12486 %1
Windows and Daylighting Group%2 LBL-12486 %0 Journal Article %D 1981 %T Calculating Heat Transfer Through Windows %A Michael D. Rubin %G eng %L LBL-31724 %1
Windows and Daylighting Group%2 LBL-31724 %0 Conference Paper %B International Energy Management and Facilities Improvement Show %D 1981 %T Energy-Saving Benefits of Automatic Lighting Controls %A Francis M. Rubinstein %B International Energy Management and Facilities Improvement Show %C Chicago, IL %8 09/1981 %G eng %L LBL-13299 %1
Lighting Systems Group%2 LBL-13299 %0 Report %D 1981 %T Quicklite 1, A Daylighting Program for the TI-59 Calculator %A Harvey J. Bryan %A Robert D. Clear %A James Rosen %A Stephen E. Selkowitz %X
This paper presents a set of daylighting programs that can be run on a TI-59 hand calculator. The paper gives the program listings, the step-by-step procedures for using the programs, worksheets, and a worked sample problem.
The programs calculate interior horizontal illumination levels or daylight factors from a window. The user can specify the location of the calculation point, or, if a printer is available, the locations of a grid of points. Calculations can be performed for both CIE clear and overcast sky conditions.
The direct sky component calculation uses Riveros approximation for window transmission. The interreflected component calculation uses a split-flux approximation.%I Lawrence Berkeley Laboratory %C Berkeley %P 27 %8 04/1981 %G eng %1
Windows and Daylighting Group%2 LBL-12248 %0 Conference Paper %B 6th International Passive and Solar Conference %D 1981 %T Thermal Performance of Windows Having High Solar Transmittance %A Michael D. Rubin %A Stephen E. Selkowitz %X
Antireflected polyester films and low-iron glass sheets have values of solar transmittance that are substantially higher than those of their untreated counterparts. The plastic films utilize coatings to reduce losses due to surface reflectance and the glass is made with low levels of impurities to reduce absorption within the material itself. In this paper, we discuss the optical and thermal properties of these materials and derive the solar and thermal characteristics of windows incorporating high transmittance glazing layers. Comparisons among these and other types of windows are made on the basis of net energy use for residential buildings in winter.%B 6th International Passive and Solar Conference %P 141-145 %G eng %L LBL-12288 %1
Windows and Daylighting Group%2 LBL-12288 %0 Conference Paper %B 6th National Passive Solar Conference %D 1981 %T The Use of Physical Scale Models for Daylighting Analysis %A Harvey J. Bryan %A Alexander Lohr %A R. Christophe Mathis %A James Rosen %X
A process is described for determining the quantitative and qualitative features of a proposed daylighting design using physical scale models. The paper presents and discusses in detail several issues (i.e., modeling techniques, testing, measurement, visual analysis and photography) that must be resolved before physical scale modeling can be undertaken. Finally, a physical scale modeling case study is presented which illustrates many of the issues outlined as well as a photographic sequence of the physical scale modeling process.%B 6th National Passive Solar Conference %C Portland, OR %P 865-869 %8 09/1981 %G eng %1
Windows and Daylighting Group%2 LBL-13305 %0 Journal Article %J Energy %D 1980 %T Lighting Controls: Survey of the Potential Market %A Francis M. Rubinstein %A Rudolph R. Verderber %X
This study describes the impact of lighting management systems that dynamically control lights in accordance with the needs of occupants. Various control strategies are described: scheduling, tuning, lumen depreciation, and daylighting. From initial experimental results, the energy savings provided by each of the above strategies are estimated to be 26, 12, 14, and 15%, respectively.
Based upon a cost of $0.05-0.10 per kWh for electric energy and a 2-, 3-, or 4-yr payback, target costs for a simple and a sophisticated lighting management system are found to be $0.14 and 1.89 per ft2 respectively, for a cost-effective investment.
A growth model, based upon an extrapolation of the increase in building stock since 1975, indicates that the commercial and industrial (C & I) building stock will grow from 40 x 109 ft2 in 1980 to about 67 x 109 ft2 by the year 2000. Even with the use of more efficient lighting components, the energy required for this additional C & I stock will be 307 x 109 kWh compared to the 230 x 109 kWh used today. Adopting controls would reduce this requirement to 243 x109 kWh, an increase of only 13 x 109 kWh above current use.
The specified information is used to analyze the economic impacts that using these systems will have on the lighting industry, end users, utility companies, and the nations economy. A $1-4 x 109 annual lighting control industry can be generated, creating many jobs. The estimated return on investment (ROI) for controls for end users would be between 19 and 38%. Utilities will be able to make smaller additions to capacity and invest less captial at 7-10% ROI. Finally, the annual energy savings, up to $3.4 x 109 for end users and about $5 x 109 for utilities, representing unneeded generating capacity, will be available to capitalize other areas of our economy.%B Energy %I Pergamon Press Ltd. %V 8 %P 433-449 %G eng %N 6 %1
Lighting Systems Group%2 LBL-11209 %& 433 %0 Conference Paper %B 5th National Passive Solar Conference %D 1980 %T Transparent Heat Mirrors for Windows: Thermal Performance %A Michael D. Rubin %A Richard Creswick %A Stephen E. Selkowitz %X
The thermal performance of a window system can be improved by the application of a transparent heat mirror coating. This paper discusses the ways in which optimum thermal performance can be achieved for a variety of conventional and advanced window designs. Residential applications are emphasized.%B 5th National Passive Solar Conference %P 990-994 %G eng %L LBL-11408 %1
Windows and Daylighting Group%2 LBL-11408 %0 Conference Paper %B 4th National Passive Solar Conference %D 1979 %T Average Transmittance Factors for Multiple Glazed Window Systems %A Stephen E. Selkowitz %A Michael D. Rubin %A Richard Creswick %X
Multiple glazing is the most common static method of improving the insulating properties of windows. For simplified calculations of solar heat gain a single value for transmittance is chosen, usually the normal transmittance. Whenever such a method is applied, the normal transmittance should be replaced by an averaged value which takes into account the daily and seasonal variations of weather and the angle of incidence.%B 4th National Passive Solar Conference %P 383-386 %G eng %L LBL-9654 %1
Windows and Daylighting Group%2 LBL-9654 %0 Conference Proceedings %B Proceedings of the International Conference on Energy Use Management %D 1979 %T Infiltration and Air- Leakage Comparisons: Conventional and Energy-Efficient Housing Designs %A David T. Grimsrud %A Max H. Sherman %A A.K. Blomsterberg %A Arthur H. Rosenfeld %B Proceedings of the International Conference on Energy Use Management %C Los Angeles, CA %G eng %2 LBL- 9157 %0 Journal Article %J ASHRAE Trans. %D 1978 %T Infiltration-Pressurization Correlations: Detailed Measurements on a California House %A David T. Grimsrud %A Max H. Sherman %A Richard C. Diamond %A Paul E. Condon %A Arthur H. Rosenfeld %B ASHRAE Trans. %P 851-865 %8 12/1978 %G eng %N 85(I) %2 LBL-7824 %& 851