| 摘要 |
<P>PROBLEM TO BE SOLVED: To prevent freezing in a water circuit inside a heat pump unit 1a without circulating hot water inside a hot water tank 2a. <P>SOLUTION: When a three-way valve 14 is switched to a refrigerant bypass circuit 11a side, a freezing preventing operation for operating a heat pump cycle with low ability is set, and a controller 5 stops ordinary cycle operation, a freezing preventing operation is carried out if a water temperature detected by water temperature sensors 16 and 17 is below a predetermined value. In this way, when the heat pump cycle is operated with low ability and water supply for hot water is passed at a low flow rate through the water heat exchanger 7 and a bypass passage 19, hot water heated by the water heat exchanger circulates through a water circuit in the water heater via the bypass passage 19, so that freezing in the water circuit inside the heat pump unit 1a can be prevented. The hot water inside the hot water tank 2 is not affected. <P>COPYRIGHT: (C)2007,JPO&INPIT |
