What hot water system should I have?

[webmaster]

There are several hot water options available all with slightly different names and terminology; mains pressure, unvented, thermal store, indirect, sealed system etc. All these are variations on themes, each has its own advantages and disadvantages.

In terms of energy efficiency, however, it is not possible to state that one type is better than another. As with the radiators v. underfloor question the primary factor which influences the efficiency of the hot water is the type of boiler. After this other important factors include the amount of insulation and the heat exchanger surface area. Increasing the surface area of the heater exchanger (usually a copper coil) increases the speed with which the cold water in the cylinder absorbs the heat from the boiler circuit. This in turn lowers the temperature of the water going back to the boiler so reducing the amount of boiler 'cycling' and, in the case of a condensing boiler, increases the time that the boiler will be in condensing mode.

It is also worth bearing in mind that there is little point in installing an electric shower when there is a store of hot water sitting there a few yards away. Although this may seem obvious it is seen quite frequently on house plans. If it is a powerful shower you want then use a mains pressure system or a pump but do remember that these use more hot water and therefore more energy.


Regards, Webmaster
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Regards, Webmaster