Dear AC_Hacker,
Thanks for reply, as i mentioned i used values from the 2002 code - the following are the composites of the structure:
walls: 25cm white stone + 3 cm polystyrene + 10 cm concrete block.
expected U value is 1.8 W/m2.k
roof: 18 cm concrete hollow block + 3 cm polystyrene + reinforcement concrete. expected U value is 1 W/m2.k
a study i found from the internet by "Mohammed Ibrahim Daher, Jordan International Energy Conference 2011 – Amman" suggested 10 cm polystyrene to achieve 1.13 W/m2.k for walls and using foam concrete for roofing to achieve 0.2 W/m2.k.
Is there a practical and inexpensive way to measure R values for roof and walls?
I would start by enhancing the insulation, to achieve 3 tons only.
for my calculation it is below:
extreme temp is -5 c ( Oops forget to convert to f)
HDD 1924
ceiling area 1668 ft2, R = 5.6
Walls area 1372 ft2, R = 3.15
windows area 403 ft2, R = 1.6
floor area 1668 ft2, R = 20 assumed.
volume 16421 ft3, 0.5 air change per hour
occupants 5.
new design loss after rectify extreme temp is = 57174 btu/hr
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