Boiler & radiator size query.

[Agile]

Doubling the single panels can often help a lot as it increases output by about 70%.

But each room really needs to be calculated on its own.

I am not impressed by his efforts! Brings our speciality into disrepute!

Tony

 

[D_Hailsham]

You need to find out if the rads are up to heating the rooms they are in.

http://www.radcalcs.com/[/QUOTE]
I agree on the first part, but radcalcs is the last thing I would use.

They do not use a standard method with u-values and temperatures but factors, e g one outside wall is a factor of 1, two is 1.15 and three 1.5. The most ridiculous is the 'comfort type' factor. Average is 1, Slightly warmer is 1.2, Tropical Plants is 1.5 and Ignore Global Warming is 2.

In some cases, changing a factor had no effect on the BTU required!

A more reliable calculator is Here

 

[Whitespirit66]

Thanks for your advice.
Would it be a good idea to replace some of the small radiators with one larger single radiator and use the old smaller one(s) to put two into another room. i.e. two in some rooms. Or, should I replace them all and throw the small ones away?

Whatever suits you really. If it were me and all the rads were new, I would be looking to re-use the rads rather than bin some. It comes down to the layout of you home and whether 2 smaller rads in a room is practical for you, compared to one large ones. In some respects, 2 smaller rads may give more even heating of a room.

Remember though that swapping a small rad for a larger one will require minimal pipework, but adding an extra rad to a room will require more alteration work.


Thanks Mr Hailsham. Will have a look at the calculator that you suggest.

 

[Stivino]

I'll have a look at that calculator too, thanks for the link.
I understand that it would be much easier to just fit a wider radiator, what if I just put double ones in the place of the singles, would that be the same as a wider one?

 

[Stivino]

I've done the calculation on both of those sites and the both give completely different results for the same input figures
http://www.radcalcs.com/ says I need 5072 BTU's.
http://www.homesupply.co.uk/radiator_output_calculator.php says I need 2787 BTU's.
So, how to proceed?

 

[D_Hailsham]

I've done the calculation on both of those sites and the both give completely different results for the same input figures
http://www.radcalcs.com/ says I need 5072 BTU's.
http://www.homesupply.co.uk/radiator_output_calculator.php says I need 2787 BTU's.
So, how to proceed?

I would trust Homesupply over Radcalcs any day.

A good way of checking is to do the calcs for all rads, using both sites, and then compare the total for each site against the result of using the Whole House Boiler Size Calculator.

Rad total should never be less than the calculated boiler size, but if it is greater that's OK as it means the boiler can run at a lower temperature and still produce the required output.

PS It's now standard to quote boiler and rad outputs in kilowatts.