Calculating heat loss and size a radiator

Calculating a heatloss for a village hall


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Calculation of resistances for an insulated wall

Surface Area (m2) U Value (W/m2K) Thermal Loss (w/K)
Floor 104 0.60 62.4
External Walls 102 0.40 40.8
Windows 16 2.00 32.0
Roof 146 0.35 51.0
Roof Windows 9.6 2.20 21.0
Internal Walls No Loss - -
Total for building fabric     207.3

Village HallAssuming a Room Temperature is required at 20C and an outside temperature of 0C
The heat loss for the fabric = 207.3 X3=20 = 4146 W

Air Infiltration is assumed at one air change per hour.

Heat loss = Volume X specific heat X difference in Temperature
= 520m3 X 0.33 X 20 = 3432 W

Total Heat Loss = 4146 +3432 = 7578 W

Would suggest 6 radiators having at least 1263 W output.

From Manufacturers Catalogue 600mm high X 1000mm long double panel radiator gives 1336 W this would do the job

To test a U Value, watch our videos on calculating a U value and testing a U value