Long, Zhang; Jiankai, Dong; Yiqiang, Jiang; Yang, Yao - In: Applied Energy 133 (2014) C, pp. 101-111
When an air source heat pump (ASHP) unit is used for space heating at low ambient temperatures in winter, frost may form on its outdoor coil surface. Since the accumulated frost adversely affects its performance and energy efficiency, periodic defrosting of the outdoor coil is necessary....