[GSBN] Can someone validate RT's US R to (metric) lambda conversion?

[Graeme North]

the conversion I have used is that R value (imperial) ft2*degF/Btu =  
5.86 X R value (metric) in m2 *degC/W for the same thickness of  
material - an easy way of converting R values from imperial top  
metric to another for the same construction - it also helps demolish  
extravagant insulation  claims made for some american materials when  
proponents have not done the conversion.



10.05 * 5.86 / 39.37 inches/m = 1.49 so its close



Graeme
Graeme North Architects
49 Matthew Road
RD1
Warkworth
tel/fax +64 (0)9 4259305

graeme at ecodesign.co.nz
www.ecodesign.co.nz


On 16/06/2009, at 3:48 AM, contact at lamaisonenpaille.com wrote:

> Hello,
>
> For the purpose of publishing Bruce Kings book "Design of SB  
> Buildings" in french I would appreciate someone from this list  
> confirming Rob Tom's conversion below (for page 187):
>> A thermal resistivity of 1.45 ft^2*hr*degF/Btu*inch (Murrican)
>> converts to 10.05 m^2*degC/W*m (SIU).
>>
>> The thermal conductivity, or lambda value = 1 / thermal resistivity
>>                                           = 1 / 10.05  m^2*degC/W*m
>>                                           = 0.0994 W/mK  lambda (λ)
>
> Thanks,
>
> André de Bouter
> La Maison en Paille
> www.lamaisonenpaille.com
>
>
>
> _______________________________________________
> GSBN mailing list
> GSBN at greenbuilder.com
> http://greenbuilder.com/mailman/listinfo/GSBN

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.sustainablesources.com/pipermail/gsbn/attachments/20090616/d9b64797/attachment.htm>