Hi, just met the local vicar in my capacity as a local councillor and was discussing his cold church hall. Its a prefab 1970s? rectangular wooden building with hopefully some insulation in the walls- maybe 100mm? and double glazing. Mostly one big room 20x 10m? It has v old panel heaters at the moment. They have classes, approx one a day there. He's thinking about infrared heaters. Surely aircon units would be a better idea for getting the temp up quickly for occasional use? Any thoughts. I was thinking about helping with the cost out of my budget. He's keen to do it in as green a way as possible. Obviously insulating it properly would be best but not sure there's any money for that at present.

Whether air-to-air heat pumps would be economic would depend on usage and installation costs. Combs Village Hall in Derbyshire had a lot of success with air-to-air, but they had guaranteed fairly consistently high usage.

Conventionasl wisdom has been, as the vicar seems to know, that radiant gets a cold hall/church 'comfortable' fastest; heating up the air is slowest by a long chalk. Unless the 'wisdom' has changed.

The radiant output coming off the surfaces and structure will take a matter of days of heat input, to heat up enough to play a part in 'comfort', but once done, and kept going fairly constantly, provides best comfort for least fuel, as it allows air temp (hence building heat loss) to be quite low. High radiant and lower air temp is what humans find most comfortable - the higher radiant heat being received on the body compensates for the lower heat being received via air temp.

So air-to-air would seem the poorest and most fuel-hungry way to intermittently heat a hall. But techniques to instead heat up the surfaces and structure, so they radiate more, accompanied by lower air temp - like UFH - are not good at intermittent heating have to be kept going more or less continuously. However, in chuches, it is poss to put warm-air generators under the pews, so that as long as people stay put they sit in a local warm-air bubble.

Which, for a hall, leaves strong prob overhead radiation as the 'instant' intermittent alternative, which has to overcome both the lack of warm radiation from surfaces and structure, and the cool air. It can be quite effective, for least fuel, but isn't capable of real toasty comfort, as it always only warms the parts of the body that it can 'see', while leaving your backside fully exposed to the cool air and the lack of warm radiation from surfaces and structure.

It can't simply be made stronger, otherwise you'll feel like you're under a grill. But you can choose between small-area red-hot electric radiators, or much larger-area so called 'black heat' piped heaters, which are a major installation, being supplied either with hot water, or with burning gas being blown along pipes. Large-area 'black heat' will come much closer to true comfort, compared with dead-easy small-area red-hot electric radiation, but at considerable cost.

Solar thermal on the roof heating an insulated water tank and hot water bottles for all that need or want it. And jumpers too

Thanks for these comments. I will feed them back. Upgrading the fabric would make a big difference too I would imagine.

Posted By: bogal2They have classes, approx one a day there.

If they're exercise / Yoga classes then infra-red would be cheap and effective. If they're classroom-type classes then, as Tom has mentioned, they're line-of-sight only, so anything under a desk won't be heated and wouldn't be a good solution.