Radiator sizing (again) - are these sizes reasonable

[imrreh]

Hello all,

So I'm looking to sort out the central heating, I've done some calculation using a calculator at bestheating website and it has given me the following figures

room	Height	Length	Width	Window Area	BTU	Watts
Bedroom1	2.32	2.63	2.44	1.44	1666	487	2 outer walls
Bedroom2	2.32	3.45	2.98	2	1329	389
Bedroom3	2.32	3.81	3.6	1.96	1555	455

So the first surprising thing was that the smaller room (bedroom1) requires a larger ouput rad, I can understand that there are 2 outer walls but does that really make such a difference? The current rad that is fitted is the smallest one out of all the bedroom and the room heats up reasonably well.

For bedrooms 2 and 3 I could use a radiator that is 400high x 700mm wide but that may look a bit odd as the windows are around 2m wide. So would it be ok to put wider rads in and use a TRV to control the temp?

Thanks

 

[Chalked]

Radiator calculations are based on heat loss. Not just the size of the room. So 2 outside walls makes a big difference.
Download the Mr combi app. It seems the most accurate to me.

 

[AlexGas]

Hello all,

So I'm looking to sort out the central heating, I've done some calculation using a calculator at bestheating website and it has given me the following figures

room	Height	Length	Width	Window Area	BTU	Watts
Bedroom1	2.32	2.63	2.44	1.44	1666	487	2 outer walls
Bedroom2	2.32	3.45	2.98	2	1329	389
Bedroom3	2.32	3.81	3.6	1.96	1555	455

So the first surprising thing was that the smaller room (bedroom1) requires a larger ouput rad, I can understand that there are 2 outer walls but does that really make such a difference? The current rad that is fitted is the smallest one out of all the bedroom and the room heats up reasonably well.

For bedrooms 2 and 3 I could use a radiator that is 400high x 700mm wide but that may look a bit odd as the windows are around 2m wide. So would it be ok to put wider rads in and use a TRV to control the temp?

Thanks

If you'd like to work it out properly, get yourself this book:
CIBSE Domestic Heating Design Guide 2015