| 摘要 |
<p>PURPOSE:To contrive to reduce the heat loss by a system wherein the temperature of feed water and the calorie of remaining hot water are grasped and the electric energy to apply for set hot water quantity to be used is calculated. CONSTITUTION:The hot water quantity intended to be used the following day is inputted to a hot water quantity setting means 5 and the thermal calorie to be stored within a hot water storage tank before midnight energizing time ends is calculated based upon the detected values of a feed water temperature sensor 6 just after the entry of midnight power supply time zone and of a remaining hot water sensor 9 by means of an arithmetic unit 7. In addition, an arithmetic unit 10 calculates the thermal calorie of the remaining hot water. Furthermore, an arithmetic unit 11 calculates required energizing hours based upon the net thermal calorie to be applied. Accordingly, a timer unit 12 starts to energize a heating element 13 in the midst of midnight power supply time zone so as to obtain the required power supply hours calculated by the arithmetic unit 11 at the expiring time of midnight power supply. In such a manner as mentioned above, the reduction of radiation loss is contrived.</p> |
