Heat Loss is calculated as:
(Square feet of wall or ceiling)/(average r value of the materials covering it)*(temperature differential) + btus needed for air infiltration loss.
It's more complicated than that, but that's the gist of it.
There are free calculators online. I like the one that Slantfin has on thier website.
I tear things down and build them up.
Last edited by Clutchcargo; 11-20-2007 at 04:04 PM.