Quote:
Originally Posted by Ormston
The thermal performance quoted is only possible in the correct construction which is usually a 1" batton either side of it to create an air gap. This makes the minimum thickness of the insulation construction 2"+.
|
So when you say "batton" you mean the same thing as a spacer?
I'm really curious about 'air-space' requirements for various insulations, and what the rationale for a particular requirement is. I know that air is a good insulator. I also know that if the air space is too large, air currents can begin 'self pumping' and seriously reduce the effectiveness. Some folks have said it has to do with the wavelength of heat, but I did a calculation of the wavelength of unfra-red light, and the length of a wavelength is 700 nanometers (nm) to 1 mm, so it is very, very small.
Quote:
Originally Posted by Ormston
Whilst I could use it in my loft(attic) conversion I,m currently doing I decided to stick with polyurethane foam with foil on both sides. Using 4 layers of various thicknesses adding up to 150mm (6") which means 8 layers of foil so u guess it is multi foil in a way.
|
So will your configuration have air gaps, between layers?
Quote:
Originally Posted by Ormston
AC will be interested in your results as to how you get on with dig multi foil.
|
Yeah, me too. I went shopping yesterday at my local fabric warehouse, looking for some kind of very thin microfiber filler material, that was not dense and felted or closely woven. There weren't very many choices. But I did find almost exactly what I wanted, and it was fine, thin lambs wool filler material. Pretty gorgeous stuff, really (All the ladies at the fabric store kept saying, "you're going to do what!?"). So I bought enough to make a ten layer test piece that is 18" x 18".
I'm in the midst of a construction project myself (power tools and building debris are ruling my existence), so hopefully I'll be able to have my sample within a week.
Best,
-AC