Case Study of Ground-Source Heat Pump Applications in Hot and Humid Climates

Abstract

Despite the fact that the use of ground-source heat pumps (GSHPs) in cold and dry climates has been studied for decades, the technical and economic applicability of GSHPs in a hot and humid climate such as Florida is yet to be determined. Eight cases in the states of Florida and Alabama were studied in comparison with conventional air source heat pumps. Data were collected through site visits or interviews, as well as from literature and published data sources. The case studies showed that GSHPs were more favorable in nonresidential applications when incentives were considered, but not favorable for residential applications without incentives. With incentives, applications in residential settings were still debatable because of potentially negative net present value and generally long payback time. Conversely, without incentives, the use of GSHPs in nonresidential applications is feasible if long payback time is not problematic for facility owners. Consistent with other studies, initial costs were found to be the most sensitive factor for the use of GSHPs or air source heat pumps. In addition, a preliminary comparison between the results of this study and other studies of GSHP use in cold and/or dry climates seems to suggest that the feasibility of GSHP use in residential applications varies significantly between the two types of climate. Applications in hot and humid climates seem to have more uncertainties.