| 摘要 |
PURPOSE:To maximize a ratio of an amount of utilizable hot water to the capacity of a hot water storage tank. CONSTITUTION:Since an output control device 9 is provided for an auxiliary heat source which is operated during a period in which the output of a heat pump during the starting of operation set by a clock is stabilized and controls a boiling-up temperature to a target temperature, a layer 6a having a temperature gradient in a hot water storage tank 6 is minimized through regulation of a boiling-up temperature to a constant target temperature from the initial stage of operation. Thus, the increase of the temperature of water entering a heat-exchanger 3 between water and a refrigerant does not occur until a time just before completion of boiling up and running of the heat pump can be stably continued. Thereby, a ratio of a quantity of utilizable hot water to capacity of a hot water storage tank can be maximized. |
