"Will Dean" wrote in message
.. .
wrote in message
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Looking at the heat loss calculations that I did for my house before I
renovated it I got values ranging from 15Kw if I installed no
insulation to 8kw if I installed as much insulation as was feasible.
These included 3.6Kw for air changes. This is for a detached house
about 10M square on 3 floors so it should need a lot more heat than a
terraced house.

Unless I'm completely wrong about calculating vent losses, then your air
change figure sounds extremely low. Even at one change an hour (very low
as an average for the house), a three storey 10x10 house is going to need
something like 10*10*7 [height, guess] * 1 * .33 * 24 [tempDrop] = 5.5kW.

How did you do the air-change loss?

This is 2 storey, somewhet smaller than your example: I've got roughly 30m^s
per floor in the main bit, 10m^2 in the back addition so total 40m^s plan
area. Each floor is 2.4m high (call it 5m total), so total house volume
approx 40 * 5 = 200 m^3.

With 2 air changes/hour and 20C difference that'd be 200 * 2 * 20 * .33 =
2.6 kW, which is near enough what I've got on my spreadsheet (actually I'v
been using a factor of .36 which I got from a post of Andy's sometime back).


--
John Stumbles
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Bob the builder / it'll cost yer
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