Heat-pump water heater

摘要

In a heat-pump water heater (1), a control unit (5) has heat-radiation determining means (S20, S21, S22) for determining a heat radiation from refrigerant to outside air in an air heat exchanger (9) based on a water temperature flowing into a water heat exchanger (7), and the control unit selectively performs a general cycle operation and a bypass operation in accordance with a determination result of the heat-radiation determining means. That is, when the water temperature flowing into the water heat exchanger is lower than 60 DEG C, the general cycle operation is performed. On the other hand, when the water temperature is equal to or higher than 60 DEG C, the bypass operation is performed. <IMAGE>