| 摘要 |
<p>PURPOSE:To provide an effect of energy saving by a method wherein a plurality of electric heaters arranged at an upper part and a lower part within a hot water tank are controlled three modes of an alternative energization of all the electric heaters, an energization of only the electric heaters at upper part and a decreasing of set temperature of hot water in addition to only the upper electric heaters. CONSTITUTION:Water is supplied to a lower layer of a hot water accumulating tank through a water supplying pipe 3, the water is heated by two electric heaters 4 and 5 arranged at an upper part and a lower part and then hot water is taken out of the upper layer. Upper and lower temperature sensors may control an energization of each of the electric heaters 4 and 5. In case that hot water is not used so much at night, for example, only the upper electric heater is controlled for its energization and then hot water is accumulated at the upper layer within the tank with a less amount of calorie. In case that a surrounding atmosphere temperature is low, only the upper electric heater is energized and a predetermined temperature of hot water is decreased to save an electric fee. A controller 14 may control an energization of the electric heater with a simple operation at an operating part 18 and enable a variation of the predetermined temperature to be programmed.</p> |
