| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a heat pump type water heater with improved energy saving performance and very high usability. <P>SOLUTION: The heat pump type water heater includes: a heat pump cycle composed by annularly connecting a compressor 4, a refrigerant-water heat exchanger 5, a pressure reducing device 6, and an evaporator 7; and a heating circuit composed by annularly connecting a hot water storage tank 3, a circulation pump 10 conveying low temperature water in a lower part of the hot water storage tank 3 to the refrigerant-water heat exchanger 5, and the refrigerant-water heat exchanger 5. By changing heating capacity of the heat pump cycle in response to a residual hot water amount in the hot water storage tank 3, a target heating temperature of hot water produced by the refrigerant-water heat exchanger 5, and a supply temperature of water supplied to the hot water storage tank 3, and determining an overnight heating start time, heating operation with favorable operation efficiency is made possible, and the energy saving performance can be improved. <P>COPYRIGHT: (C)2010,JPO&INPIT |
