Condensing boilers, a summary
Condensing boilers, a summary
A condensing boiler is a finance saving innovative boiler that incorporates an additional heat exchanger so that the red-hot exhaust gases transfer most of their inherent heat to pre warm the mains water to be heated. Once working at maximum efficiency, the water steam produced in the burning process distills back into water giving up the latent heat of vaporisation.
A consequence is that this water, refered to as condensate, typically acidic, needs to be piped away to a waste pipe or soakaway. The boiler will have to be fixed against a wall and the output gases will rise through the flue. Hot water is first delivered by a small recepticle tank to help quick hot water availability.
How can I get the right size of boiler?
It was a past times practice to install oversize boilers. Whilst this ensured that there was little chance of the boiler failing to meet the need for heat, irregardless of the winter weather, it also meant that they were not running a full output, and so running below their maximum efficiency. If you have bettered the energy efficiency of your home since the current boiler was installed in your house, you will probably find that you will be able to fit a lower-ranking capability boiler than before.
Make sure you get advice from a CORGI installer before purchasing your next boiler
If I fit a condensing boiler should I put in big radiators?
The main driver for lower fuel use from a condensing boiler results from having a larger heat exchanger. Larger radiators would allow lower return temperatures, and so push efficiency higher still, but the additional saving is not shown to be cost effective, bearing in mind that the system is is only using a small part of its overall capacity for the main heating months. That in all probability remains true, though the smaller heating demand for new build may well mean that homeowners would now allow over-sized radiators more willingly.
The SEDBUK initiative reviewed these matters, during which it was argued whether condensing boilers required to be processed differently from others. The decision was that they need not, and the test results forall the boiler types use the same SEDBUK formula.