calculate radiator sizes

peat

Can anyone tell me how to calculate hot water radiator sizes required for known room dimensions?

paul_h

There's a few ways to do it, but here's a simple one...

1.Measure volume of room in cu.ft. i.e length x width x height
2.Multiply by 5x for living rooms/dining rooms, 4x for bedrooms, 3x anywhere else
3.Add 15% for rooms facing north
4.Add 20% for french doors
5.Deduct 10% for double glazing

This will give the required BTU for your rad.

derrick

3412 BTUs = 1 KW

Ted_Hutchinson

radiator size calculator

amd

Brilliant find Ted. I always thought that our plumber used too small radiators for our old (uninsulated) brick walled house!!! No wonder we've been freezing.

moneysavingplumber

Software is far more accurate than other methods and the correct written method is far more complicated and long winded than above. Mears calculators notoriously oversize, so software as linked to above is best, most radiator companies produce software of their own.