Calculating rads size.

sub55

Any body know of a calculation method to ascertain what an appropriate rad size would be ?
In terms of size, mm by mm, or BT use given room area or volume?

murraymint77

Try this http://www.diy.com/diy/jsp/bq/templates ... ulator.jsp

Ginjafro

I've used rad calculators prior to my very recently installed central heating. To be honest they may provide a rough idea of requirements but IMO you can't beat the knowledge and experience of a good plumber. They will take account of "cold walls", direction of house, prevailing winds and so on. Also, it is well worth considering the best insulation you can get for the walls (£99 grant for beading!) and loft space to prevent all that lovely heat escaping.

sub55

I can find online calculators , although i was really after the mathematical calculations behind it.
For a little bit more background , im actually a self employed plasterer and i have an appointment to see a prospective client. As part of the contract they want their existing skirting rads removed and conventional rads installed. Under normal circumstances i would sub contract it out to a local plumber for the sake of ease. But as work ia at premium at the moment , i `ll do it myself. Now the plumbing side of it is no problem at all , but when they ask me , how big the rad`s got to be in order to look like i have a vague idea , as to what im talking about it would be nice to calculate it out . Its all bullshit really.

murraymint77

This may be more help then. http://www.diydoctor.org.uk/projects/rads.htm

andy162

There is no simple "rule of thumb" calculation for rad sizing. I use a Mears Guage & it's a complicated bugger to use. It has to take into account room volume, types of walls ie, insulated, cavity or not & what the room is used for. Bedrooms for instance will require a smaller output to a lounge. My advice would be to leave the quotation open until you have consulted a plumbers merchants. A good merchant will have the calculator to hand so as to size the rads accordingly. Take the necessary info with you & you'll be given the correct advice & price.

I would recommend K-Rad radiators if you can get them, good quality & half the price of Stelrads. I would fit thermostatic radiator valves while your at it & add some corrosion inhibitor to the system when you're done (providing it's not a Primatic system in the house, recommend Sentinel X100)

Hope this helps.