Development of Compact Type Solar Thermal/Ground Coupled Heat Pump Hybrid System for Heating and Cooling of Residential House

In this study, the compact type solar thermal and ground coupled heat pump hybrid system (hereafter compact type hybrid system) for space heating and cooling and hot water heating for residential house has been developed. The working characteristics and the thermal performance of the hybrid system have been particularly investigated. This hybrid system was designed in order to address the existing disadvantages of solar thermal/ground coupled heat pump system. For our design, all parts except solar collector and heat pump were integrated into a single product in a factory. The compact type unit includes two buffer tanks, expansion tank, pumps, valves, controller, etc. This system has an advantage of easy installation with simple plumbing work even when placed in narrow space. An analysis of thermal performance and operational characteristics of this hybrid system was carried out experimentally. The thermal charging and discharging time of buffer tank and its characteristics by ground coupled heat pump and heat pump cop according to geo-source and buffer storage temperature have been studied. As a result, this system was found to conform well to the heat load without any other auxiliary. To be specific, the operating hours of the ground coupled heat pump as a backup device of solar thermal can be reduced significantly by solar heat. Finally, this system was installed in KIER Zero Energy Solar House (KIER ZeSH) for the demonstration. The demonstration results were very satisfactory.