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Re: GBlist: Hemp Insulation?



At 02:49 PM 6/13/97 -0000, you wrote:

>First question, can anyone convert the metric thermal conducivity? Is 
>there a web site with this conversion. (I've found several sites with the 
>typical conversion factors, but none with this one.)

W/m *K   X  6.935 = BTU * in/(hr*ft^2*deg F.)  ie. k - value, so one inch of
0.048 W/m^2 *K  is worth 0.33 BTU * in/hr*ft^2*deg F = thermal conductivity
Inverting this, of course, converts to R-3 per inch.  Acceptable.

but one inch of  0.13 W/m^2 *K  is worth 0.9 BTU * in/hr*ft^2*deg F or
roughly R 1.1 per inch; could be a good subtitute for opaque single glass. 
  - my guess is that the 0.13 is actually conductance (not conductivity),
for a thick sample eg. 40 cm (15 in.)
  - then the units should be W/m^2 *K   and multiplying by 0.176 will yield
.023  BTU/(hr*ft^2*deg F. or  R-44
  - but it's only a guess

[conversions from ASHRAE Fun-da-mentals,  Ch. 35]  

Them little numbers and letters is elusive - best left to professionals, who
have little else to recommend them but dogged determination.
See below.

>Second. What's the general impression of this product? 

WOW!  Far flipped away!
What R they smokin' in that test  lab?
Mark E. Kelley III, PE
Building Science Engineering
85 Depot Rd.    Harvard MA  01451
508 456 6950
dragon@world.std.com

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