[Tijeras_Slim]

Interesting, is there a formula you are familiar with?

Thanks

[gorush]

The ratio of the numbers allow an honest comparison of differing materials. Styrofoam, for example, provides about R-10 per inch of thickness.

[gorush]

"Interesting, is there a formula ..."

I'm sure there is and it probably has something to do with the time it takes for X number of BTU's to raise a specified insulated space 1 degree Celsius, but I have no idea what that would be, but thankfully, the ratio's tell me all I need to know. The higher the R value the better.

We recently built an earth-sheltered home and separate shop with R-50 ICF's (insulated concrete forms) with a closed loop geothermal heating and cooling system. We heat and cool 3500 sq ft for under 700/year.