Impact of global warming on performance of ground source heat pumps in US climate zones

• Published in: Energy conversion and management 2015-09, Vol.101, p.632-643
• Main Authors: Shen, Pengyuan, Lukes, Jennifer R.
• Format: Article
• Language: English
• Subjects: Building performance; Climate; Climate change; Climatology; Construction; Cooling systems; Energy efficiency; Energy management; Ground source heat pump; Grounds; Heat pumps; Morphing technique; Weather
• ISSN: 0196-8904; 1879-2227
• DOI: 10.1016/j.enconman.2015.06.027

•Used morphing method to have downscaled hourly local weather data from GCM.•Selected representative cities in different climate zones in the US for case study on GSHP performance.•Used hourly building simulation tools (eQuest and TRNSYS) to project GSHP performance in future.•Analysis on GSHP performance in 2050 for both residential and office building in the US are conducted. Ground source heat pumps (GSHP) have attracted increasing attention because of their high energy efficiencies. The aim of this paper is to study the performance of (GSHP) in future climate conditions (2040–2069) by using projected future hourly weather data of selected representative cities in the US to estimate future ground temperature change. The projected hourly weather data and estimated ground temperatures are input to an hourly simulation tool (TRNSYS and eQuest for this research), which provides reliable coupling of GSHP system and building performance. The simulation results show that global warming will decrease the energy efficiency of GSHP in US residential buildings because a rise in inlet and outlet water temperature is predicted for GSHP systems during the cooling season and because buildings will become more cooling dominated in the future. For office buildings, although the cooling performance of GSHP will not drop significantly under future climate, the overall energy efficiency for the system will decrease due to the increasing energy consumption of the ground loop pump. In the future, considering the significant ground heat imbalance for GSHP operation, GSHP will become less competitive both economically and technically than it is now in the context of US climate zones.