Impact of ambient temperature and humidity on the performance of a novel anti-frosting air source heat pump system

The defrosting process of air-source heat pump systems are often associated with deficits of heating interruption, high energy consumption, and inevitability of system performance degradation. To address these issues, an anti-frosting air source heat pump that employs surface modification and active airflow technology is introduced in the present work. It achieves frost suppression by removing unfrozen condensate droplets on the superhydrophobic heat exchanger with high-speed airflow, thereby reducing the frequency of defrosting or eliminating it altogether. The study investigates the complex interactions between the frost growth rate, energy consumption of anti-frosting and the system operation state, ultimately revealing the comprehensive impact of ambient temperature and humidity on system performance. To this end, a coupling model of frosting and heat pump system is developed, the influence of ambient parameters on the airflow parameters and system operation characteristics is analyzed, and the system performance map with varying ambient parameters is obtained. The study simulates the operation of the system under heating design parameters of 54 typical cities in China, comparing the performance enhancements under different climatic zones. The findings demonstrate that the anti-frosting system exhibits significant energy-conservation potential in hot summers and cold winters zone, with a COP improvement up to 21 %.