[sanjayuk (OP)]

Hi, I hope you can help. I have a technical question. I have searched with google to find an answer, but with no luck.

My question is: If we have any building material, say plasterboard, and it is emmitting some of it's heat by Infra-Red, and you want to recapture that lost heat by placing a reflective surface on one side of the plasterboard, (so the emmitted heat reflects back into the plasterboard, how close can you put a reflective surface to the plasterboard? Can the reflective surface actually be in contact with the plasterboard, or will that render the reflective properties useless?

Any help would be greatly appriciated.

Many Thanks,

Sanjay

[Ron Hughes]

I wouldn't think it could be any closer than the longest wavelength of infrared. Is there a material that reflects infrared? A mirror may reflect a portion of it but not a lot.

[Bored chemist]

It might not matter.
If you coat the plasterboard with foil (which is a very good reflector) then it will be a very poor emitter.
Job done.