[Greenbuilding] thermal bridging--letting it go

[Corwyn]

On Aug 1, 2006, at 00:34, Keith Winston wrote:
> Heat conduction is from hotter to cooler points. You could perhaps more
> accurately imagine that heat (like water) is "trying" to go in all
> directions, but can only actually succeed going in the direction of
> cooler areas. The stud is the coolest point because the heat is
> transfered through and out of the stud fastest (into the cold outside
> air), compared to the Icynene. Heat will try to transfer through the
> Icynene, but due to the high R-value, will not move well through the
> foam, and the foam will, in essence, not be cooler.

Looking from the outside, the studs will be the warmest part.   Thus, 
for any given slice of wall (crossways to the heat flow, parallel with 
wall surface) the stud will be the warmest section and heat will move 
from it into the cooler insulation.  This is why thermal bridging isn't 
as bad a simple computation by R-values would indicate.

Thank You Kindly,

Corwyn

-- 
Corwyn
Kermit didn't know the half of it...
http://www.greenfret.com/
corwyn at greenfret.com