BTU Calculation help please

[dwalsh1]

Hi all. I want to replace the rads in my front room and to get the right size I'm trying to calculate the BTUs but I'm having agro calculating so can someone who knows what they're doing help please. The room size is
7.6m long
4.0m wide
2.5m high
window dimensions are 1420mm H x 820mm W, 1350mm H x 1790mm W
3 outside walls 220mm solid brick
Wooden floor with heated room above
Thanks

 

[Ric2013]

Problem with calculating BTUs is we tend to be able to be reasonably accurate with walls and floors, but ventilation has a huge effect compared with heat loss through building fabric.
I could spend ages calculating it using U values, but I'd have to make certain assumptions and I could be out by a large factor. So you may as well Google 'room heatloss calculator' and use one of those guides.

 

[cjg]

always add little extra on, fit trv if this is not your control rad, if you under cal, you will never heat the room,