Geothermal heat pumps (GHPs), sometimes referred to as GeoExchange, earth-coupled, ground-source, or water-source heat pumps, have been in use since the late 1940s. WaterFurnace used to be a distributor for Command Aire however, Trane, Inc. Information about ground source heat pumps, geothermal heating and cooling systems and the role of sound geothermal in providing such systems for residential and commercial applications.
They use the relatively constant temperature of the earth as the exchange medium instead of the outside air temperature.
