On 01/12/2012 20:49, wrote:

U values... I thought brick/cavity/brick wall was 1.73?

Sounds a bit high to me...

A 9" sold wall would be about 2.2

I get something quite different... Brick Commons - 102mm --- 0.132
Air Cavity - 50mm ------- 0.180 Brick - 102mm ----------- 0.132
Plaster - 6mm ----------- 0.025

Total R Value = 0.469 where U = 1/R = 2.132

According to the figures we have he

wiki.diyfaq.org.uk/index.php?title=Heat_loss

An uninsulated cavity wall should be about 1.0

Just noticed a cell in an old spreadsheet got corrupted and defaulted
to 1.37 which I am sure is wrong, thought it was 1.73, but
calculating from data I get 2.132 (6mm plaster, most are 13mm
obviously).

I think your spreadsheet sounds closer...


--
Cheers,

John.

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