| 摘要 |
PROBLEM TO BE SOLVED: To provide, for example, a heat pump water heater capable of easily and surely achieving reduction in defrosting operation time, and to provide a heat pump water heater capable of preventing fluid return to a compressor during a defrosting operation.SOLUTION: A heat pump water heater 1 comprises: a heat pump unit 20 in which a compressor 21, a hot water supply heat exchanger 22, an expansion valve 23, and an outdoor heat absorption heat exchanger 24 are connected by a refrigerant circuit 25; a bypass circuit 31 provided in the refrigerant circuit 25 and bypassing the expansion valve 23; and a defrosting solenoid valve 32 provided in this bypass circuit 31. The heat pump water heater 1 further comprises defrosting operation control means stopping heat exchange in the hot water supply heat exchanger 22 and starting a defrosting operation when frosting of the outdoor heat absorption heat exchanger 24 is detected. The defrosting operation control means controls the defrosting solenoid valve 32 to be opened/closed either according to a discharge refrigerant temperature of the compressor 21 or at regular intervals during the defrosting operation. |
