All the
modern boilers we fit are condensing boilers, whether they are
combination
(combi) boilers, system boilers or heat only boilers. They are the easiest
way of making a big improvement in the overall operating efficiency of an
existing low temperature, wet, central heating system. Condensing boilers
can be natural gas, liquid petroleum gas (lpg) or oil fired. If the only
fuel options are oil or lpg, it is well worth considering other heat
sources such as solar power or a heat pump as part of the heating system.
How
they work;
The term
‘condensing’ refers to the way in which the boiler recovers heat that
would otherwise be lost through the flue. The main heat exchanger within
the boiler uses the cooler water coming back to the boiler from the
central heating system, to condense out water vapour held within the
products of combustion, in the form of steam, from the flue gasses. This
condensation is what gives the appliance its name ‘condensing boiler’.
Because this process recovers latent heat from within the fumes, which are
the products of combustion from burning the gas, it greatly increases the
efficiency of the boiler.
By this
process, a condensing boiler can achieve efficiency levels in excess of
90%. This means that for every £100.00 you spend on gas for heating,
£90.00 worth goes into the heating system water. Like all modern, high
efficiency central heating products, it is important that a condensing
boiler is correctly fitted to operate to it’s optimum efficiency. By
installing the correct controls and by increasing the output size of
radiators within the central heating system, it is possible to ensure that
the boiler runs at maximum efficiency for as much of it’s operating time
as possible. The location of the drain point for the condensate is
important, partly because the condensate is basically mild sulphuric acid,
and it needs to be drained through plastic pipe work. Also in very cold
weather, it is possible for it to freeze in the drain pipe, possibly
shutting the boiler off.
