59 of 74  Construction of Giresun Wastewater Treatment Plant  Tender Dossier Volume 3 Employer’s Requirements  The Contractor shall provide details of the design study to be carried out for heating and ventilating,  including the drawings showing the general arrangement of the proposed layout.  The buildings to be heated shall comply with relevant heat insulation regulations, and the calculations  showing in the architectural drawings that the respective average heat transfer coefficient value of  windows/external walls has been achieved shall be provided together with heating designs.  In any locations constituted as an enclosed volume such as valve room, pump room, etc., natural  circulation shall be provided. To do this, at least 2 windows, etc. opposing to one another shall be  placed and insulated against external effects.  Ventilating  Ventilation systems shall provide that buildings:  - Coarse screen and inlet pumping station  - Fine screen - Blower buildings  - Return and excess sludge pumping station  - Sludge dewatering building  - Workshop and Storage - Digester Control/Operation building (each room) - Laboratory (Separate ventilation apart from Administration Building) - Primary Sludge, Thickened Sludge and Dewatering Facilities Feeding Pumping Station  - Transformer Buildings  - Emergency Diesel Generator Building  - Service, Potable and Firefighting Water Pumping Station  - Building for Chemical Phosphorous Precipitation  Ventilation systems shall provide a safe working environment to comply with national regulations and  to the key-principles given in Section 2.6.2.  3.3.11 Pipe Materials Pipes to be used at the plant; Connection pipes between units : HDPE PE100 (GRP for pipes with diameter  > 1600 mm)  Process air pipes : Stainless steel 1.4404  Drop legs for process air pipes  Above water  : Stainless steel 1.4404  Below water  : HDPE PE100, PN16  Aeration grid pipework below water  : HDPE PE100, PN16 Odor Pipes  : GRP Biogas pipes  : HDPE PE100, PN10 (in underground  installation)  Biogas pipes  : Stainless steel 1.4404 (section inside the  buildings)  Sludge pipes : HDPE (section outside the buildings and in  underground installation)  3_Vol3_d4.3_Section 3_Plant Description_GIR_rev08 