| 摘要 |
<p>Hot water is generated using the water-jacketed tube heater type of apparatus in which, on demand, mains cold water passes through a high efficiency heat exchanger 4, 4' immersed in a heated thermal storage medium 2, such as water, contained in a cylinder 1 whereby the cold water becomes heated and is conveyed at high pressure to a point of use such as a sink, bath or shower. Substantially the whole of the thermal storage medium 2 is continually maintained, by means of a controller 13 and one or more electric immersion heaters 10, 10', at least one of which extends into the lower regions of the cylinder 1, at about 90 DEG C in the off-peak (night-time) electricity tariff period and at about 60 DEG C in the peak (day-time) tariff period. The controller 13 receives a signal from a temperature sensor 12 located in a upper region of the cylinder 1. Maintaining the specified temperatures in the medium, particularly that in the peak period, reduces the time taken to obtain hot water through the heat exchanger 4, 4'. <IMAGE></p> |
