BTU Online Calculator discrpancy

[alig31]

Hi all,

I put the same bedroom dimension into mrcentralheating.co.uk/btu-calculator and into homesupply.co.uk/radiator_output_calculator.php and got wildly different values. The former recommended approx twice that of the latter......now I am confused.com.

Room Size 2.5H x 3.25W x 3.963D one outside wall double glazing and cavity wall insulation on first floor of house, room above is heated.

The former gives a value closer to the current radiator size although the radiators are pretty old.

Any recommends which one I should use and why the vast difference.

Regards Al

 

[joni os]

Practical experience with existing radiators is more relevant than generalised theoretical calculations. Replace with rads. of similar output, or be prepared to add blankets to the bed when assumptions of zero heat loss through internal walls and ceiling prove unreliable.

 

[Gary80gas]

The existing rad is always a good guide, and if it creates the heat you want going a lot smaller could be disappointing and you could end up running your heating hotter to compensate. Quite why the figures are so different, they shouldn't be twice the difference. try several calculators, beware putting a pimple sized rad in room based on price