| 摘要 |
PURPOSE:To contrive to enhance heating capability and to shorten operating time, by changing over a hot water temperature set point so that it is low when the enthalpy of a heat source in a heat pump heating circuit is not higher than a predetermined value and it is high when the enthalpy is higher than the predetermined. CONSTITUTION:A heat pump heating unit 1 is constituted of a compressor 2, a heating heat exchanger 3, a throttle 4 and a heat source heat exchanger 5, the heat exchanger 3 and a hot water storing tank 8 are connected to each other by a circulating passage 9 provided with a circulating pump 11, a hot water temperature detector 14 is provided at an outlet part 13 of the heat exchanger 3, and the rotating speed of the pump 11 is controlled by comparing the hot water temperature with a hot water temperature set point in a controlling circuit 10. The enthalpy of the heat source is detected by a sensor 20 detecting the wet- bulb temperaure of air which is the heat source in the heat exchanger 5. When the enthalpy is higher than the predetermined value, the hot water temperature set point is changed over to a high level, and when the enthalpy is not higher than the predetermined value, the set point is changed over to a low level. |
