The performance of shallow GSHP in buildings for heating and cooling: A case study in Jordan

Abstract

The versatility of heat pump technology in heating and cooling applications is attracting much attention. Thanks to its great efficiency and inexpensive capital and operating expenses, it has found widespread use. One major downside was a sharp decline in heat output and COP as outside temperatures fell. When calculating the COP of such devices, ambient temperature is a major factor. According to studies done in the past, working in a comfortable temperature range is much better than doing so in extreme heat or cold. The ambient conditions near the surface are more stable and less prone to fluctuations than the air temperature at the surface. In this study, we compare the efficiency of two different working fluids (R134a and R290) in an ideal vapor compression cycle when operating at subsurface (-2 m) ground temperature and at the temperature of home water wells in northern Jordan. The heating and cooling modes are the focus of this research. The proposed system is mathematically modeled, validated, and solved. The results show that the heat pump's efficiency improves by 10% to 11.2% during the colder months. Meanwhile, summertime improvements ranged from 9.8% to 27.4%. Last but not least, R290 refrigerant could replace R134a if the risk of ignition is considered.

Keywords

• Ground source heat pump (GSHP)
• Coefficient of performance
• Ideal refrigeration cycle
• R290
• R134a