Btu requirements

[Steve]

I have been using the plumbcentre online btu calculator and I'm a bit confused.

My 3.2x4.3m living room, with cwi, concrete floor, dg 2sqm window, needs 5000btu/h according to the calculator.

Originally i picked a double panel 600x1600 rad. About 9000btu/h. I picked this on the basis that it looked/felt right in that space, prior to doing any working out.

We took out of the room two radiators. Both old.

I know I should overspec the heating somewhat, but is my chosen rad overkill?

I'm going to go around and properly work out all the heat requirements for each room if this is appropriate and I shouldn't size rads by gut feeling.

 

[JohnD]

Time to move into the 1970's and use kW

 

[Agile]

Exactly! Been kW since 1980 !

You have not described your property construction, but in worst case should not need more than about 100W per sq. m.

So the calculator is about right.

Unless you are working as a heating engineer I don't understand why you think that you should be able to guess the size required.

Tony

 

[Steve]

It's a semi with injected filled cavity walls and will have loft insulation by winter. Double glazed throughout.

 

[AGAS]

Central Heating Radiators BTU's Calculator

 

[motorbiking]

1.5KW sounds about right for the size, the 2.8Kw rad you have chosen will be fine as long as you fit a thermostatic valve. At least it will heat the room a bit quicker.

 

[bernardgreen]

A larger radiator means you can operate it at a lower water temperature for the same heat output as a smaller radiator at a higher water temperature. The advantage of this is that most boilers are more efficient if the return water temperature is lower

 

[Steve]

Central Heating Radiators BTU's Calculator

This calculator brings up nearly half the btus of the plumbcentre one. Whats that about?

 

[AGAS]

tongue in cheek mate , stick with KW's