LAUSR

Abstract Air source heat pump (ASHP) and heating tower heat pump (HTHP) systems are both environmentally sustainable space heating systems. HTHP system can effectively avoid the frosting issue of ASHP systems, but requires higher initial investment. In order to explore the applicability of the two systems, this paper presents a comparative study between HTHP and ASHP systems in different climatic regions. Mathematical models were developed for HTHP and ASHP systems and validated by field experiments. Case studies were carried out in four different climatic regions using the numerical model to analyze the energy consumption, system efficiency and economic efficiency of the two systems. The results showed that the ASHP system was superior in electrical power input in the four regions. The EER of the HTHP system was higher than that of the ASHP system by 3% and 2% in Regions III and II (Xi'an and Shanghai) while lower by 7% and 6% in Regions I and IV (Shenyang and Chongqing). The annual cost of the HTHP system was higher than that of ASHP system by 9% and 11% in Regions I and IV, while lower by 5% and 4% in Regions II and III. Based on these comparisons, recommendations about how to choose HTHP and ASHP systems for different climatic regions were presented, to instruct future optimization and utilization of HTHP and ASHP systems.