"IMM" wrote in message
...

"Neil Jones" wrote in message
...

"IMM" wrote in message
...

"Neil Jones" wrote in message
[snip]

Total losses for house = 12.3kW

Downstairs losses are 51.9% of total losses from house.

Losses through:-

Ground floor 4%
Downstairs solid wall 19%
Downstairs cavity wall 1%
Downstairs windows 6%
Ceiling to upstairs 3%

Roof 6%
Upstairs solid wall 18%
Upstairs cavity wall 2%
Upstairs windows 6%

Increase the loft insulation to 350-400mm and do the calcs again.

OK.
Thermal conductivity of mineral wool = 0.038

1/0.5 + (0.3/0.038) = 2 + 7.9 = 9.9.

U val = 1/9.9 ~ 0.10

Losses through ceiling reduced to 70 * 0.10 * 21 = 147W

Saving 588W, 5% of the total loss previously. How much does it cost
to
buy 70 m2 loft insulation, at a depth of 300mm?


What was the answer to this?