A large fan placed in an exterior doorway to pressurize or depressurize a building to determine its air leakage rate, expressed in air changes per hour or cubic feet per minute. The result is better insulation and use of fewer resources, in addition to cost savings. Several variations are possible. Can also refer to gas-fired systems. Combination System Heating system that uses the domestic water heater for both water and space heating.
Conditioned space is separated from unconditioned space by a thermal envelope.
Desuperheater Device that takes waste heat extracted by heat pumps or air conditioners and uses it to heat domestic hot water. E Seal E Seal is the electric utility industry's energy efficiency and environmental housing initiative. At the program's core is a certification system, which ensures that electric utility new construction programs exceed the highest nationally recognized energy-efficiency and environmental criteria. The amount of cooling provided per unit of electricity purchased. The higher the EER, the more efficient the air conditioner.