"Newshound" wrote in message
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"Keith Dunbar" wrote in message
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"Tony Bryer" wrote in message
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On Fri, 14 Sep 2007 05:15:42 GMT Keith Dunbar wrote :
Further to previous posts about calculating radiator sizes, my 17th
century
timberframed house has been renovated as far as I can tell by replacing
all
the old wall materials with rendered breeze blocks. The walls seem to
vary
in width in different places, but the minimum seems to be 9 inches,
presumably solid breeze block. My attempts to google for a u value
haven't
been very successful. Can anyone suggest a reasonable u value for this
wall construction that I can use in my calculations?

If they are medium density blocks (1400kg/m3), then about 1.5. Aerated
concrete (Thermalite/Celcon, 500kg/m3) about 0.6.

--
Tony Bryer SDA UK 'Software to build on' http://www.sda.co.uk

I guess I should just set an arbitrary in-between figure to work with -
perhaps 1.5?

Keith

Sample drilling will tell you whether it's lighweight blocks or not. Just
an old carbon steel drill: will go straight through thermalite, won't
touch concrete
Ah, I think I may already know the answer then. But I shall do a drill test
later. If it is concrete, what u value would we be talking about for 9".

Keith