Performance assessment of a vertical ground-source heat pump system with wall heating and cooling

Abstract

Extensive studies on ground-source heat pump systems' performance have been published in the literature. Coefficient of performance (COP) on heating and cooling modes significantly influences thermal energy economics for these systems. This study is an experimental investigation of a real building's heating and cooling system. Heating and cooling season analysis of a vertical ground-source heat pump (VGSHP) system with wall heating and cooling (WHC) is investigated. WHC systems are equipped with heating coils mounted on the walls, through which water is circulated. The system used is located in Yildiz Renewable Energy House (YREH) at Yildiz Technical University and fulfills the heating and cooling demands of both YREH and a living room in a neighboring dormitory. System parameters were recorded every second during the year 2010. For heating season, calculated overall system efficiency was 67.36%, while the GSHP unit's efficiency was 85%. In addition, overall system COP was 2.76, while the ground-source heat pump (GSHP) unit's COP was 4.13. As for the cooling season, calculated system efficiency was 74.90%, while the GSHP unit's efficiency was 80.76%. Furthermore, overall system COP was 4.38 while the GSHP unit's COP was 4.78. The heat extraction rate was 50 and the heat rejection rate 54 W/m of bore depth for the heating and cooling periods, respectively, which corresponds to the range already reported in the literature