Page - 139 - in Water, Energy, and Environment - A Primer

heatexchanger tubingormoreshallowholeswithmorenumerous heat exchange loops of tubing. The tubing, filled with heat exchange fluid, is grouted to the earth to enhanceheat exchange. Initially, in the mid 1990s, many heating and cooling contractors were not familiar with GHPs. Thus, they did not bring them to consumers’ attention, despite the fact that there was some encouraging history. AGHP had been installed in a hotel in Kentucky in the 1980s and its energy demand was shown to be less than that of an identical hotel in the same location outfitted with a traditional air-exchange heat pump. Nevertheless, no subsequent commercialization took place. In response, once the benefits of usingGHPswere understood, the DOE initiated a joint program with the US electric utility Figure 8.17 Schematic of GHP used for cooling and heating (Source: U.S.EnvironmentalProtectionAgency). Renewableenergy 139