Re: Insulation/temp gradient

[brian whatcott <inet@intellisys.net>]

At 21:56 9/5/97 +0000, you wrote:
> ... In some of the wall components (gypsum for 
> example) the temperature falls slowly (low slope) while in another area 
> (fiberglass) the temperature falls off more quickly (greater slope).See 
> below.
>
> Question: Which is the better insulator? That is how does one interpret 
> the *physical meaning* of the slope (degrees/inches)?
>
> The key says the low slope material....
> *	David Simmons	

If you will forgive yet another electrical analogy, it is evidently
a comparable situation to a string of resistors in series.
 The high resistance drops many volts; the low resistance drops 
few volts.
The electric current ( heat flux) is limited by the highest resistance
element (thermal insulator). This is where most of the potential drop 
temperature fall) occurs.

(This is surely not a purist's analogy - to compare dV and dT is not
quite respectable...)

Regards

brian whatcott <inet@intellisys.net>
Altus OK