抄録
The objective of this study is to investigate a heat exchange performance of ground source heat pumps (GSHPs) that use the direct expansion method. This paper described an experimental result of the coefficients of performance of the GSHP system. A depth of a borehole is 30 m. The refrigerant was R410A. The experiment of heating mode was performed continuously over 48 hours. A preset value of a room temperature was changed after 24 hours from the running. Thermal performance was evaluated by a ratio of the amount of heat transferred at the indoor unit to electric power consumption of the compressor. Pressures and temperatures in the primary loop were measured when the preset value was changed during the day. The coefficients of performance of heating mode was about 4 and 7.5 when the preset value was 23℃ and 20℃, respectively.
