| 摘要 |
PROBLEM TO BE SOLVED: To provide a heat pump-type water heater capable of surely determining frosting of an air heat exchanger even when outdoor air is in a low-temperature state.SOLUTION: A heat pump-type water heater 10 has such a mechanism of raising a temperature by flowing hot water sent out from a hot water storage tank 14 into a water heat exchanger 13 to which a refrigerant absorbing outdoor heat when passing an air heat exchanger 12, and performing boiling by returning to the hot water storage tank 14. There is included control means 32 for determining that frosting is generated in the air heat exchanger 12, and switching an operation mode from a boiling operation to a defrosting operation, when a condition 1 that an average integrated value of a boiling ability continues a prescribed number of times, and a condition 2 that a value obtained by subtracting an adjustment temperature selected according to an outdoor temperature from an outdoor temperature is continuously larger in a prescribed time, compared to a temperature value of the air heat exchanger 12 are satisfied. The control means 32 memorizes a plurality of temperature ranges in association with a high-temperature adjustment temperature in a temperature range in which a temperature is lower, and selects by the condition 2 an adjustment temperature in association with a temperature range to which outdoor temperature belongs. |
