Air-source heat pumps are widely used in winter as heating units due to their higher efficiency compared to electronic heaters or gas fired equipment. However, the air-source heat pump can cause discomfort during periodic defrosting operations. In this study, a PCM unit for continuous heating was adopted to solve this problem. The PCM unit consisted of a PCM, a heat exchanger, and control valves. It was installed between the outdoor and indoor units. The performance of the proposed system was measured during both defrosting and heating operations. The indoor unit showed an average leaving temperature of <TEX>$26^{\circ}C$</TEX> after adopting the PCM unit for continuous heating during the defrosting operation.