how to choose new fire

[Deleted User]

Sorry if this is an obvious question - but I can't find the answer to it. We need to buy a new gas fire and I'm wondering how to calculate the heat output we need. I know it will be to do with the total space to be heated - this one is 2 rooms that have been knocked into one, and one room has a radiator, and the one with the fire doesn't. Does anyone know how to calculate it? Thanks.

Smiley_Dan

Assuming you want the fire to heat the room on its own, you need to calculate the heat loss for the room. This will give you a basic idea of what you need: http://www.cityplumbing.co.uk/heatLossCalculator . That's very rough and ready and assumes you live in a typically poorly built house as 99% of UK housing stock is.

What I'm not sure about is how the efficiency of a gas fire affects its stated output. You might need to get a larger output fire as a result, but you probably want that anyway to heat up the room a bit faster, then modulate down.

You probably already know this but a gas fire will not be the cheapest way to heat the room.

HappyMJ

Smiley_Dan wrote: »

You probably already know this but a gas fire will not be the cheapest way to heat the room.

Are you sure about that? A high efficiency gas fire can be the one of the cheapest ways of heating a room. I don't mean those decorative fires with a flue or chimney which draws out warm air from the room. I mean the heaters with a catalytic converter and no flue.

100% of the heat energy from the gas will be in the room. A gas boiler heats water, heat is lost from the pipes containing the hot water, electricity is required to pump the water around and more heat is lost out of the flue.

A wood fire would be cheaper if the OP has access to a source of free firewood.