Wet Underfloor Heating – Boiler Advice
Any boiler used for wet underfloor heating needs to be sized correctly. There are many heat sources that can be used for water underfloor heating systems. See page three on our quote for the maximum heat output from a water underfloor heating system.
Normally 3 kW output should be added for the hot water demand. If radiators are fitted to the heating system the plumber would calculate the total output for the radiators.
Radiators need a high water temperature as their surface area is comparatively small. When using underfloor heating water systems, the heated surface is much larger, with the floor area effectively becoming a large, low temperature radiator.
As radiators need high water temperature to work correctly, they are not very suitable for use with heat pumps. Underfloor heating water systems are made to be used with heat pumps as they require only a very low water temperature.
The best boiler to use is a condensing boiler as they are very efficient. A condensing boiler works by using the latent heat created using another heat exchanger fitted within.
Part L of the Building Regulations now demands that all new boilers fitted need to be of the condensing type.
Some customers will use Combination boilers for their heating and hot water systems. The disadvantage with a combi boiler is that they don’t supply enough hot water. It is far better to use a separate cylinder for the hot water supply. Also, combi boilers can be quite noisy.
Solar heating systems should be used to only heat the hot water supply. Biomass systems are fine for wet underfloor heating, but are mainly used in the country side.