| 摘要 |
<p>PURPOSE:To utilize midnight electric power fully, reduce natural heat dissipating loss after heat-up and increase energy saving effect by a method wherein hot-water temperature in a hot- water reserving tank is detected when a proper time has elapsed after detecting the start of conduction electrically to decide conduction or non-conduction of all exothermal bodies while the proper time is changed in conjuction with the change of setting of heat-up temperature. CONSTITUTION:In case heat-up of water is effected by providing a plurality of exothermal bodies 2, 3 at the lower part of the hot-water reserving tank 1, the water is heated up at first upon starting the conduction by one set of comparatively low-capacity exothermal body and the hot-water temperature in the tank 1 is detected when the proper time has elapsed after detecting the starting of conduction electrically to decide conduction or non-conduction of all exothermal bodies while said proper time is changed in conjection with the change of setting of the heat-up temperature. When the hot-water temperature after 3hr has elapsed from the starting of conduction under the heat-up setting of 75 deg.C is lower than 50 deg.C, for example, the water is heated up by the conduction of all exothermal bodies after 8hr from starting the conduction. When the hot-water temperature after 6hr from starting conduction effected by the low-capacity exothermal body under the heat-up setting of 60 deg.C is lower than 50 deg.C, the water is heated up by the conduction of all exothermal bodies so as to heat up it after 8hr from starting the conduction.</p> |
