Calculating size of radiator to size of room?

[Deleted User]

As you may have gathered from my post about boilers - I'm trying to sort some new central heating.

I'm contemplating buying the boiler and radiators myself and getting a corgi plumber to fit it all.

Does anyone know how to calculate what size radiators are required for the size of the rooms?

Does a double radiator give you exactly double the warmth, thus saving space, as opposed to having 2 singles? Or it that too simplistic?

Having recently moved in to my house, I've discovered the radiators are too small to heat the size of rooms they are in and my existing boiler (apparently only 18 months old) can only take one more radiator.

I can get round some of the problems by swapping existing radiators round but need to buy 3 extra ones plus the new boiler (which I haven't yet decided on).

Is there a market for second hand boilers? - as British Gas reckon mine will still be worth about £500.

Any plumbers/heating engineers here care to comment or advise?

many thanks

Woby_Tide

http://www.diydoctor.org.uk/projects/rads.htm

has a few rough calculations to work out the size of radiator you should aim for

tricky_3

Try these...

BTU calculator - http://www.heatershop.com/btu_calculator.htm
or
http://www.diy.com/diy/jsp/bq/templates/contentlookup.jsp?content=/bq_advice/planning_tools/btu_calculator.jsp

calculate the btu/hour required for each room. When you look in the rad catalogues, they will give you the btu number the radiator provides.

[Deleted User]

Thanks for the replies.

wallet_2

wickes have a sheet with figures on