efficient ...yes,
economical, depends on how big your garage is, and how well insulated & draught-proofed....?

It depends how you intend to use the garage. If you are for example going to be working at a bench in a fixed spot then an IR heater overhead of that spot will work well. But if you are constantly moving around or working under a vehicle then IR is unlikely to suit you at all.

thanks for your replies. I am converting the garage to residential use, ie visitor accomodation. So it wont be used on a regular basis. Its a solid wall/brick construction, which I will internally insulate with 75mm Celotex to floor and walls plus 150mm to roof.

On the other hand, there's no particular reason to think IR heaters are any worse than other form of direct electrical heating and they may well have some of the advantages of UFH or other large low-temperature radiators.

no one interested? Would you rather have 100% efficient or 350% efficient? simple to answer!

Is tony selling heat pumps or have I missed something ?

If your feet are cold under the table there is a 250w heat lamp used in animal husbandry
that will solve that particular problem but it does need a ceramic bulb holder and a switch to turn it off when you are no longer cold .

Tony you got me interested. You think a2a heat pumps are more efficient? Have you got any systems or suppliers to suggest? Maybe whisper any details.

Thanks for tip Tony, will do.

Posted By: SteamyTea'warm walls radiate heat'

They don't, on a nett basis, unless they're at higher temp than your skin! What they do is slow down the nett radiation emission from your skin, so you feel warmer. If nett emission from your skin is prevented, you'll feel extremely uncomfortable and eventually die, especially if you're getting nett radiation gain from the walls.

The body burns fuel (food) continually, generating energy; expends some in mechanical work, the rest in waste heat. What happens if that heat can't be dumped out? (same goes for planet Earth).

When composite surrounding air/radiant (Sol-air) temp approaches or exceeds skin temp, you can still sweat to dump heat by evaporation, or pant if you're a dog; when that cooling capacity is exceeded, and/or if you dehydrate, you're in trouble, 'heat-stroke' etc, and eventually runaway body temp.

How else do you see it working?

The body always has to be losing heat; comfort depends on how fast/slow is the loss rate.

Has anyone experimented with retroreflective optics such as those used in bicycle reflectors? I have often thought that these might be spread over the ceilings of large, under-occupied buildings such as warehouses. You'd then walk about in a little pool of your own reflected body heat.

You are probably going to tell me an extra jumper would be cheaper and just as effective.

Hi rhamdu,
Maybe more applicable to homes. Warehouses are enormous these days with few people in them. If it is possible to make people feel comfortable by clever use of radiant reflectors at say 15 C instead of 20 C then that would be something.

The only time I had experienced the effect of cold walls was when I went on holiday for a week and the home central heating was off and no cooking/telly/lights. When I got home everything was at about 12 C. Even when the air temperature was 20 C it felt cold. It took a good 3 days before it felt comfortable again. Walking into the house from a warm outside it immediatly felt cold even with 20 C air temperature.

Richard

I know it is an old thread, but I saw this tweet and it explains a lot of the discussion above. Surprised none of our more learned friends mentioned it

https://twitter.com/SandersonAidan/status/1178556350416261121?s=20

"Standard electric resistance heats the air whilst longwave infrared heats the people and internal surfaces."

And they are 100% efficient unless some heat gets radiated out of the windows

I go and look on eBay