Performance Investigation of Dual-Source Heat Pumps in Hot Steppe Climates

There has been much research last decades about the feasibility of installing air-source and ground-source heat pump systems in cold areas in North America, Europe, and China. Unfortunately, not a single study has been conducted on the usage of heat pumps systems in hot steppe regions, despite the fact that hot and semi-arid (steppe) climates are met in huge territories across the globe. Furthermore, not many papers investigated the use of dual-source heat pumps. Hence, this research is the first to investigate the performance of air-source, ground-source, and air-ground dual-source heat pump systems in warm and steppe zones. The studied systems were evaluated by seasonal energy consumption, coefficient of performance, and energy efficiency ratio. Results revealed that high average thermal conductivity of soil and lower energy demand for heating and cooling in hot steppe climate than hot arid and cold climates. This implies low borehole heat exchangers length, high coefficient of performance of ground-source and dual-source heat pumps, and low energy consumption. Ground-source heat pumps were found to consume up to 60% less than air-source heat pumps, and dual-source heat pumps up to 50 and 79% with respect to air-source and ground-source heat pumps, respectively.