Keith Dunbar wrote:
"The Natural Philosopher" wrote in message
...
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?

well I have K values (divide by width in meters for U Value)

aerated concteret 0.16
lightweigght block 0.19
med block 0.51
heavy concrete 1.63
screed 0.38
Brick 0.64

9" is about 125mm or 1/8th of a meter, which gives possible U values
depending on density, from 1.28 up to 12 or 13 or so.

I would suspect around 4-5. Similar to brick.

Ultimately it doesn't matter cos you want to line it all anyway don't you?

Or do you need to expose timbers?
I hadn't planned to alter the walls in any way - I'm just trying to check on
radiator sizes. Are you sure about these values? Values I have vary from
0.65 (11" insulated brick cavity) to 2.44 (9" solid brick). Trouble is I
have no easy way to find out what type of block was used. The only clue is
that the work was done in 1967.

\
If you are simply sizing radiators, you will want to oversize anyway for
fast warm up times.

Assume 9" solid brick.


Keith