| 摘要 |
PURPOSE:To reduce maintenance charge by a method wherein a heat pump is operated only during a time band in which an energy cost is small, in the hot- water reserving type hot-water supplier in which a midnight electric power-utilizing water heater and the heat pump are combined. CONSTITUTION:A hot-water temperature operator 20 operates a hot-water temperature to be heated up by necessary heat amounts, operated respectively by a necessary heat amount operator 16 operating a heat amount to be reserved in a hot-water reserving tank and a remaining hot-water heat amount operator 19 operating the heat amount of remaining water, and a lower part temperature detected by the remaining hot-water heat amount and a lower part temperature sensor 14. The characteristic data of the heat pump unit is being inputted into a memory unit 23 and an operating time setting unit 24 sets the operating times of a heater 2 and the heat pump unit 3 based on respective temperatures of lower and outer upper parts of the hot-water reserving tank, an operated value obtained by the hot-water temperature operator 20 and the data of the memory unit 23. According to this method, a daytime energy cost etad is compared with the midnight energy cost etan and when etad>etan, the heat pump unit 3 is operated by daytime general purpose electric source. |
