| 摘要 |
<P>PROBLEM TO BE SOLVED: To improve efficiency of a heat pump type water heater by shortening a defrosting operation time by suppressing boiling-up of the water in a heat exchanger for hot water supply during a defrosting operation of the water heater. <P>SOLUTION: This heat pump type water heater comprises a compressor 14, a water-refrigerant heat exchanger 15, a variable pressure reducing mechanism 16, an evaporator 17, a water circulation pump 13 for circulating the supplied hot water in a hot water storage tank 10 to the water-refrigerant heat exchanger 15, a supplied hot water temperature detecting means for detecting a temperature of supplied hot water in the water-refrigerant heat exchanger 15, and a defrosting operation control means performing the control to stop the water circulation pump 13 and then increase an opening of a passage of the variable pressure reducing mechanism 16 on the basis of the temperature of supplied hot water detected by the supplied hot water temperature detecting means, when conditions for starting the defrosting operation of the evaporator 17 are satisfied. <P>COPYRIGHT: (C)2009,JPO&INPIT |
