Will my radiator be big enough?

pledgeX

I'm planning to knock through the wall which separates my kitchen and hallway. It will be approx 3.5m by 5m when done.

Currently there is a radiator in each room, but due to the new kitchen layout I'll only have space for one. How can I find out if the existing radiator will be 'powerful' enough? They're both 100cm x 60 cm x 6cm.

I've used a couple of calculators but they gave wildly different results (2800 vs 4700 BTUs). I looked on Screwfix and can see that they sell radiators that are the same size as my current ones, and output enough BTUs. However, I guess just because they're the same size doesn't mean they'll output the same.

Obviously the easiest thing would be just to wait and see, but for the sake of redecorating I'd rather get it right first time. Any thoughts?

Smiley_Dan

Assuming you have a "normal", i.e. not high performance house, work out the heat loss for the room by using http://www.cityplumbing.co.uk/heatLossCalculator

Then find a radiator that gives the correct output. E.g. http://www.simplifydiy.com/plumbing-and-heating/radiators/power

The wildly varying heat loss estimate may be down to the fact that houses have wildly varying performance, from some which have no heating required, to some which require a small forest to be burnt each winter. Therefore, assumptions are made.

If you are really keen you can perform a proper heat loss calculation. You'll need the volume of the rooms, the external wall perimeter, the U value of the walls and floors (assuming above is heated) and an idea of your air tightness, ideally.

Maybe another way is to work back - using the second link, work out your current kW output and if necessary upgrade the radiator to cover that power requirement.