Instruct: Given a question, retrieve documents that answer the question.
Query: When were thermostats invented?
A thermostat is a device for regulating the temperature of a system so that the system's temperature is maintained near a desired setpoint temperature. The thermostat does this by switching heating or cooling devices on or off, or regulating the flow of a heat transfer fluid as needed, to maintain the correct temperature. The thermostat was invented in 1883 by Warren S. Johnson.
Edward E. Freeman invented a system to control a hot air furnace that uses three thermostatic switches for its operation. A room thermostat starts the stoker. Another thermostat (or limit switch) opens the stoker circuit when the air in the furnace reaches a predetermined temperature, irrespective of the fact that the room thermostat may still call for heat. This second thermostat operates to prevent unsafe conditions due to overheating. The third thermostat is also in the furnace. It controls a fan which forces hot air from the furnace to the rooms. It does not permit the fan to start until the air in the furnace reaches a specified degree of heat. But, at that point, it starts the fan, which continues to run, even though the limit switch has stopped the stoker, so long as the furnace is hot and the room thermostat calls for heat. The patent was on the combination patent of three thermostatic switches, not on any of the switches alone and not on the combination of the fan switch and the limit switch.
Invented in 1892 by Sir James Dewar, a scientist at Oxford University, the "vacuum flask" was not manufactured for commercial use until 1904, when two German glass blowers, "Reinhold Burger" and "Albert Aschenbrenner," formed Thermos GmbH. They held a contest to name the "vacuum flask" and a resident of Munich submitted "Thermos," which came from the Greek word "therme," meaning "heat."
Circa 1797, Count Rumford (born Benjamin Thompson) showed that endless mechanical action can generate indefinitely large amounts of heat from a fixed amount of working substance thus challenging the caloric theory of heat, which held that there would be a finite amount of caloric heat/energy in a fixed amount of working substance. The first established thermodynamic principle, which eventually became the second law of thermodynamics, was formulated by Sadi Carnot in 1824. By 1860, as formalized in the works of those such as Rudolf Clausius and William Thomson, two established principles of thermodynamics had evolved, the first principle and the second principle, later restated as thermodynamic laws. By 1873, for example, thermodynamicist Josiah Willard Gibbs, in his memoir "Graphical Methods in the Thermodynamics of Fluids", clearly stated the first two absolute laws of thermodynamics. Some textbooks throughout the 20th century have numbered the laws differently. In some fields removed from chemistry, the second law was considered to deal with the efficiency of heat engines only, whereas what was called the third law dealt with entropy increases. Directly defining zero points for entropy calculations was not considered to be a law. Gradually, this separation was combined into the second law and the modern third law was widely adopted.
The mercury-in-glass or mercury thermometer was invented by physicist Daniel Gabriel Fahrenheit in Amsterdam (1714). It consists of a bulb containing mercury attached to a glass tube of narrow diameter; the volume of mercury in the tube is much less than the volume in the bulb. The volume of mercury changes slightly with temperature; the small change in volume drives the narrow mercury column a relatively long way up the tube. The space above the mercury may be filled with nitrogen gas or it may be at less than atmospheric pressure, a partial vacuum.
The thermoscope, or Galileo thermometer, was constructed by Galileo Galilei in 1607. In 1643, Evangelista Torricelli invented the mercury barometer. Blaise Pascal (in 1648) rediscovered that atmospheric pressure decreases with height, and deduced that there is a vacuum above the atmosphere.
The Nest Learning Thermostat (or Nest Thermostat) is a smart thermostat developed by Nest Labs and designed by Tony Fadell, Ben Filson, and Fred Bould. It is an electronic, programmable, and self-learning Wi-Fi-enabled thermostat that optimizes heating and cooling of homes and businesses to conserve energy.
For some types of thermometer the relationship between the property observed (e.g., length of a mercury column) and temperature, is close to linear, so for most purposes a linear scale is sufficient, without point-by-point calibration. For others a calibration curve or equation is required. The mercury thermometer, invented before the thermodynamic temperature was understood, originally "defined" the temperature scale; its linearity made readings correlate well with true temperature, i.e. the "mercury" temperature scale was a close fit to the true scale.
Modern cruise control (also known as a speedostat or tempomat) was invented in 1948 by the inventor and mechanical engineer Ralph Teetor. His idea was borne out of the frustration of riding in a car driven by his lawyer, who kept speeding up and slowing down as he talked. The first car with Teetor's system was the 1958 Imperial (called "Auto-pilot") using a speed dial on the dashboard. This system calculated ground speed based on driveshaft rotations off the rotating speedometer-cable, and used a bi-directional screw-drive electric motor to vary throttle position as needed.
A 1955 U.S. Patent for a "Constant Speed Regulator" was filed in 1950 by M-Sgt Frank J. Riley. He installed his invention, which he conceived while driving on the Pennsylvania Turnpike, on his own car in 1948. Another inventor named Harold Exline, working independently of Riley, also invented a type of cruise control, which he first installed on his own car and on on cars belonging to friends of his. Exline filed a U.S. Patent for "Vacuum Powered Throttle Control With Electrically Controlled Air Valve" in 1951, and the Patent was granted in 1956. Despite these patents, Riley, Exline, and the subsequent patent holders were not able to collect royalties for any of the inventions using cruise control.
In 2011, Nest Labs developed the Nest Learning Thermostat. The Nest Thermostat attempted to reduce home energy consumption by addressing the problems with programmable thermostats through the use of better technology. This new technology included the implementation of sensors, algorithms, machine learning, and cloud computing. These technologies learn the behaviors and preferences of the occupants, and adjust the temperature up or down to make the occupant comfortable when they are home and to save energy when they are away. Additionally, the Nest Thermostat connects to the home Wi-Fi. This allows users to change the temperature, adjust the schedule, and check energy usage from a smartphone or laptop. All of these features were part of Nest's goal to create an easy to use thermostat that saves users energy and money.
Stainless steel was invented in 1913 by Harry Brearley of Sheffield, working for Firth Brown Steels (now called Sheffield Forgemasters). SAE 304 stainless steel is the most common stainless steel today, invented by Dr William Herbert Hatfield FRS in 1924 at Firth-Vickers known as Staybrite 18/8, a chromium-nickel steel. Many Swiss watches were mostly made out of Staybrite.
Air conditioning is the cooling and de-humidification of indoor air for thermal comfort. Using a system of coils as a solution to cool and remove moisture from muggy air in a printing plant that was wrinkling magazine pages, Willis Carrier invented and manufactured the world's first mechanical air conditioning unit in 1902. Carrier's invention – encompassing the first system to provide man-made control over temperature, humidity, ventilation and air quality, was first installed as a solution to the quality problems experienced at a Brooklyn printing plant, Sackett-Wilhelms Lithographing and Publishing Company. Air conditioning not only spawned a company and an industry, but also brought about profound economic, social and cultural changes.
Smart thermostats are thermostats that can be used with home automation and are responsible for controlling a home's heating and/or air conditioning. They perform similar functions as a Programmable thermostat as they allow the user to control the temperature of their home throughout the day using a schedule, but also contain additional features, such as sensors and WiFi connectivity, that improve upon the issues with programmable thermostats,
Some smart thermostats, such as the Nest thermostat, can learn when the house is likely to be occupied, and when it is likely to be empty. This allows automatic pre-heating or pre-cooling so the temperature is comfortable when a resident arrives. If the residents or lifestyles change, these smart thermostats will gradually adjust the schedule, maintaining energy savings and comfort.
In 1902, the first modern electrical air conditioning unit was invented by Willis Carrier in Buffalo, New York. After graduating from Cornell University, Carrier found a job at the Buffalo Forge Company. There, he began experimenting with air conditioning as a way to solve an application problem for the Sackett-Wilhelms Lithographing and Publishing Company in Brooklyn, New York. The first air conditioner, designed and built in Buffalo by Carrier, began working on 17 July 1902.
Smart thermostats are similar to programmable thermostats in the sense that they have a scheduling feature that allows users to set different temperatures for different times of the day. In addition to this feature, smart thermostats implement other technologies to reduce the amount of human error involved with using programmable thermostats. Smart thermostats incorporate the use of sensors that determine whether or not the home is occupied and can suspend heating or cooling until the occupant returns. Additionally, smart thermostats utilize Wi-Fi connectivity to give the user access to the thermostat at all times. These additional technologies have proven to make smart thermostats successful in saving users energy and money.
Cruise control automatically controls the rate of motion of a motor vehicle. The driver sets the speed and the system will take over the throttle of the car to maintain the same speed. Cruise control was invented in 1945 by a blind inventor and mechanical engineer named Ralph Teetor. His idea was born out of the frustration of riding in a car driven by his lawyer, who kept speeding up and slowing down as he talked. The first car with Teetor's system was the Chrysler Imperial in 1958. This system calculated ground speed based on driveshaft rotations and used a solenoid to vary throttle position as needed.
The vacuum flask was designed and invented by Scottish scientist Sir James Dewar in 1892 as a result of his research in the field of cryogenics and is sometimes called a Dewar flask in his honour. While performing experiments in determining the specific heat of the element palladium, Dewar made a brass chamber that he enclosed in another chamber to keep the palladium at its desired temperature. He evacuated the air between the two chambers, creating a partial vacuum to keep the temperature of the contents stable. Through the need for this insulated container James Dewar created the vacuum flask, which became a significant tool for chemical experiments and also became a common household item. The flask was later developed using new materials such as glass and aluminum; however, Dewar refused to patent his invention.
Texas Instruments invented the thermal print head in 1965, and the Silent 700, a computer terminal with a thermal printer, was released in the market in 1969. The Silent 700 was the first thermal print system that printed on thermal paper. During the 1970s, Hewlett-Packard integrated thermal paper printers into the design of its HP9800 series desktop computers, and integrated it into the top of the 2600-series CRT terminals as well as in plotters.
Nikola Tesla invented a deceptively simple one-way valve for fluids in 1916, called a Tesla valve. It was patented in 1920 (U.S. patent 1,329,559).
The development of thermionic valves starting around 1902, provided an entirely electronic method of amplifying signals. The first practical version of such devices was the Audion triode, invented in 1906 by Lee De Forest, which led to the first amplifiers around 1912. Since the only previous device which was widely used to strengthen a signal was the relay used in telegraph systems, the amplifying vacuum tube was first called an "electron relay". The terms "amplifier" and "amplification", derived from the Latin "amplificare", ("to enlarge or expand"), were first used for this new capability around 1915 when triodes became widespread.
Warren S. Johnson (1847–1911) of Wisconsin patented a bi-metal room thermostat in 1883, and two years later filed a patent for the first multi-zone thermostatic control system.
Albert Butz (1849–1905) invented the electric thermostat and patented it in 1886.
Placebo thermostats work on two psychological principles, which are classical conditioning and the placebo effect. First, placebo thermostats work in accordance with classical conditioning. Classical conditioning was first discovered by Ivan Pavlov and is a type of learning which pairs a stimulus with a physiological response. Applied to placebo thermostats, this is when the employee adjusts the thermostat and hears the noise of hissing or a fan running and consequently physically feels more content. This is due to the countless trials involving the thermostat in their own home, which actually works. The employee has paired the sound of hissing or a fan running to being more physically content due to the actual temperature change and therefore when they experience the noise at work they feel the same way even though there is no change in temperature. As long as individuals get the result they are looking for (noise associated with temperature change) they will continue with the practice (changing the placebo thermostat). Additionally, placebo thermostats work due to the placebo effect. The placebo effect works on the basis that individuals will experience what they believe they will experience. This is attributed to Expectancy theory, which states that the placebo effect is mediated by overt expectancies. The most common example is in medical testing: inactive sugar pills are given to patients who are told they are actually medicine. Some patients will experience relief from symptoms regardless. According to expectancy theory, if people believe they are going to experience a temperature change after changing a placebo thermostat they may psychologically experience one without an actual change happening. Both psychological concepts of classical conditioning and the placebo effect may play a role in the effectiveness of placebo thermostats.
The pneumatic thermostat was invented by Warren Johnson in 1895 soon after he invented the electric thermostat. In 2009, Harry Sim was awarded a patent for a pneumatic-to-digital interface that allows pneumatically controlled buildings to be integrated with building automation systems to provide similar benefits as direct digital control (DDC).
Manual thermostats (also known as analog thermostats) are the oldest and simplest type of thermostats. These thermostats are set to one temperature and do not change until the user manually adjusts the temperature.
Programmable thermostats, first introduced in the 1970s, are a type of thermostat that allows the user to set a schedule for different temperatures at different times. Most programmable thermostats also have a hold feature which suspends the schedule and effectively turns the thermostat into a manual thermostat. The idea of the scheduling feature is that users will set a warmer or cooler temperature when the home is unoccupied to save energy and money. Due to this assumed energy savings, some building codes and government programs began requiring the use of programmable thermostats. Unfortunately, due to human error in using these devices, many programmable thermostats result in more energy use than the basic manual thermostat.