Modern Condensing boilers, the fundamental truth

A condensing boiler is a high efficiency innovative boiler that contains an additional heat exchanger to enable the red-hot waste air transfer much of their contained energy to start to heat the mains water to be heated. When operating at maximum efficiency, the water vapour produced in the burning process turns revert back into water releasing the latent heat of vaporisation.

A result is that this liquid, refered to as condensate, often acidic, should be piped outside to a drain or soakaway. The boiler is required to be fitted on a wall and the output fumes will travel through the flue. Hot water is rendered by a small-scale recepticle tank to enable convenient and rapid hot water .

How can I find the right size of boiler?

In earlier years boiler installers filled bigger boilers than were called for. Although this meant that there was little chance of the boiler not meeting the heat demand, even in the coldest winters, it also meant that they were not running a full yield, and so working under their planned optimal efficiency. If you have improved the energy efficiency of your home since the last boiler was fitted, it is highly likely that you will be recommended to install a smaller boiler than the current one.

We certainly recommend you get advice from a CORGI installer before purchasing your next boiler

Do the radiators need to be outsized with a condensing boiler?

The main efficiency gain from a condensing boiler results from having a larger heat exchanger. Bigger radiators would result in cooler return water temperatures, and so result in even better energy performance, but the extra benefit has not been viewed as cost effective, as you should consider the fact that that the system is working at very low capacity for the majority of the heating season. That in all likelihood remains true, though the reduced heating demand for new build may well mean that householders would now endure over-sized radiators more willingly.

The SEDBUK initiative considered these matters, and evaluated whether there needed to be new considerations for condensing boilers. The determination was that they need not, and the test results forall the boiler types use the same SEDBUK equation.