| 摘要 |
<P>PROBLEM TO BE SOLVED: To supply a sufficient quantity of hot water even if the outside temperature is remarkably lowered or the amount of water to be heated is larger than the normal amount, keeping economy of a heat pump type water heater in a water heating system. <P>SOLUTION: This water heating system 10 comprises a heat pump type water heater 11 and an electric water heater 13 having an electric heater. When a predetermined quantity or more of hot water stored in a hot water reservoir tank 14 of the electric water heater 13 is detected by a stored hot water detecting means, the electric water heater 13 is controlled to heat water, and when a predetermined quantity of hot water stored in the hot water reservoir tank 14 is not detected and the outside air temperature detected by an outside air temperature detecting means is a predetermined outside air temperature or more, the heat pump type water heater 11 is controlled to heat water. With this structure, in usual, water is heated by the heat pump type water heater 1 restricted in running costs, and when water heating ability is running short, hot water can be heated by the electric water heater 13. <P>COPYRIGHT: (C)2009,JPO&INPIT |
