Choice of Infra-red heaters

[stevewilliams]

Currently researching infra-red heating for my local village hall. I’m getting contradictory information regarding short wave or medium wave heaters. One company insists that short wave should not be used for indoor spaces and others are quoting using short wave. The hall has intermittent use and the heaters will be wall mounted at around 3 metres. I’m slightly confused as to the right solution. Any advice much appreciated.

 

[RandomGrinch]

One company insists that short wave should not be used for indoor spaces and others are quoting using short wave.

The spread of Infrared on the EM spectrum is huge.
It is worth confirming that you are comparing heaters that are like for like.
Generally, the shorter wavelength heaters will use a tungsten filament in a quartz envelope, and will glow orange.
They provide instant heat, will warm people directly, but provide very little heat to the space.
Hence, useful for outdoors, or very large spaces where you can't hope to warm the whole room.
The direct heat can also become uncomfortable after a while (think what it would be like having the sun shining on the back of your neck for a couple of hours!).
The longer wavelength heaters won't visibly glow. Also, the longer the wavelength, the more heat they will add to the room.

If your hall is really large, then short wave heaters may be better.
If you want some heating of the space as well as the occupants, look at medium to long wave heaters.

I hope that makes sense

 

[stevewilliams]

Thanks for the comprehensive info RG. One of the specialists companies is recommending medium wave and that now seems to make sense. I assume that the medium wave will warm the floor to a certain extent?

A lot of the short wave heaters are sold as no glow or low glow so it looks like that was a problem that was addressed. Our hall is not huge but we waste a lot of energy preheating for hirers with the current old convectors - takes about an hour these cold months so not sustainable with our rising costs.

 

[RandomGrinch]

I assume that the medium wave will warm the floor to a certain extent?

IR heaters of every wavelength will heat the fabric of the building to an extent - just as we feel warm from the direct IR, so will the walls and floor, and eventually the ceilings and floors will absorb and re-emit IR themselves.
I may be wrong, but I believe the difference with the medium and long wave heaters, is that there is less reflectance and better absorption of the IR by the surfaces.

A lot of the short wave heaters are sold as no glow or low glow so it looks like that was a problem that was addressed

'No glow' should hopefully be more comfortable.

Our hall is not huge but we waste a lot of energy preheating for hirers with the current old convectors - takes about an hour these cold months so not sustainable with our rising costs.

Apart from the purchase and installation costs to consider, it's also worth noting that the IR panels will be running continuously at their specified wattage.
If they turn off, it won't take long for the surfaces to lose their heat. Whereas convector heaters will cycle on and off on their thermostats, when the air in the room is up to temperature.

If possible, see if you can get the installers to bring demonstration units to your hall - this may give you the best idea of what they are like to live with.

 

[stevewilliams]

Good points. Our problem is intermittent use so the convectors are on early, are working hard to heat the hall which is eventually toasty but often then nice and warm and not used after a class etc has finished. They are also very hot to the touch so a risk for things like mother and toddler groups. They have also been accidentally left on by hirers so we’re looking for simple push bottom timers for control.

Is it possible that our convectors (30 years old) are not thermostatically controlled? They seem to stay on - maybe the hall never gets to temperature? I take your point about IR being on continuously - it’s going to be 6 or 8 2.4kw IR heaters so quite a cost to balance against the convectors having to be switched on early.

Like most village halls we‘re hoping to get grants to upgrade the heating and lighting and initial enquiries suggest that shouldn’t be a problem otherwise it’s fundraising!

Many thanks for all your advice.