| 摘要 |
<P>PROBLEM TO BE SOLVED: To solve a problem on the impairing of hot water supplying performance when defrosting conditions are met during the supply of hot water in a case where a heat pump type hot water heater has two heat pump circuits. <P>SOLUTION: This heat pump type water heater having two heat pump circuits, has a defrost starting time difference determining part 17 for estimating the time when two evaporators start the defrost on the basis of an output temperature of each evaporator, and outputting a signal to a main control part 8 when the estimated value is smaller than a set value. The main control part 8 gives the opposite commands (to decrease operating frequency in compressor starting defrost earlier, and to increase operating frequency in compressor starting defrost later) to a first compressor control part 7 and a second compressor driving part 9 driving each of the compressors on the basis of the signal, whereby the meeting of defrost starting conditions is delayed while keeping the constant performance, and the impairing of the hot water supplying performance caused by the meeting of defrost starting condition during the supply of hot water can be reduced. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
