| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a technology for efficiently performing an additional heating operation of hot water stored in a terminal such as a bathtub even under hot-water exhaustion or when there is the risk thereof. <P>SOLUTION: The present invention relates to a water heater having: a required heating value calculation section for calculating a heating value required from starting heating hot water stored in a bathtub by means of an additional heating unit to reaching a first target temperature; a storage heating value calculation section for calculating a storage heating value that is a heating value of hot water stored in a hot-water storage tank when starting heating with the additional heating unit; a virtual additional heating value calculation section for calculating a virtual additional heating value that is a virtual heating value to be added to the storage heating value by heating the hot water in the hot water storage tank by means of an upper-limit heating capability of a heat pump unit; a heating value difference calculation section for calculating a heating value difference that is a difference when subtracting a total sum of the storage heating value and the virtual additional heating value from the required heating value; and a setting section for setting a second target temperature that is a target value of a temperature of hot water to be stored in the hot-water storage tank and a flow rate per unit time of a heat pump side circulation pump, on the basis of the heating value difference. <P>COPYRIGHT: (C)2012,JPO&INPIT |
