Field testing and performance analyses of ground source heat pump systems for residential applications in Hot Summer and Cold Winter area in China

To conserve energy, ground source heat pump (GSHP) system has been used worldwide for cooling and heating buildings, and there is a persistent concern in the performance of the system. In this study, the performances of five residential GSHP systems in Hot Summer and Cold Winter (HSCW) area in China were examined. Data were acquired through field testing, operation record and long-term monitoring. And outdoor climate parameters, water temperature characteristics, cooling load characteristics, system efficiencies and energy consumptions, heat extraction and rejection imbalance were analyzed. Field test data were used to analyze the dynamic cooling load characteristics and the energy efficiency of the heat pump units and systems. Energy consumption was statistically analyzed. The results show that the weighted average Coefficient of Performance (COP) of the heat pumps and system Energy Efficiency Ratio (EER) varied from 3.36 to 5.94 and 1.95 to 4.35, respectively. Positive correlation of high cooling load and high COP was presented. More heat extraction than rejection was found, which was relevant to domestic hot water supply. Furthermore, long-term distributions of ground side water outlet temperature were used, and the skewness and kurtosis were introduced into the quantization evaluation method.