radiator efficiency

[tp123]

Hi,
Just a quick question or two,

I have two old single flat radiators in my lounge which I am told are arround 1200btu each, the boiler seems to be working all the time to get the room up to temp, now if I were to replace them with two double convector rads of the same physical size but with a higher btu, say 4000 each (various calculators give an average of 8000btu as the recomended size for the room). With the new rads would:-

a, the boiler use more oil to heat the same space if the thermostat was set to the same temp as it is now?

b. the radiators stay hotter for longer when the boiler is switched off until the room thermostat clicks in again ?

I guess what I'm trying to assertain here is if I replace my rads with new ones will they be more efficient ?

regards.

 

[Agile]

Radiators are 100% efficient!

You pay for the fuel used to heat the room.

Hotter the room the more fuel.

To give you the comfort you want and the increased fuel consumption you need larger rads.

Replacing a single plain panel with a double convector you get about double the heat output.

Tony

 

[tp123]

Thanks for the reply Tony,

so if the radiator is double the size does this mean it takes double the fuel to heat the same space.

In my world I'm thinking that if I get a higher heat output radiator to heat the same space as a lower heat output radiator, I can heat the space quicker, the thermostat will switch the boiler off once the room is up to the desired temperature using less fuel, than as opposed to now with the lower heat output radiator the room never actually gets up to the desired temperature so the boiler is constantly on, trying to achieve the temperature the thermostat is set to.

I'm confused, am I missing something here...............

 

[mogget]

I don't think you're missing anything.

If the radiator has twice the heat output, it will consume twice the fuel... while it's on.

However, you are correct that the room will heat up quicker and the thermostat will turn the heat off sooner, so all in all it balances out.

Warm room = more fuel, cool room = less fuel

For example, a 4 kilowatt heater on for 25% of the time, produces the same heat and uses the same fuel as a 1 kilowatt heater on for 100% of the time.

(near enough, anyway).

 

[tp123]

Thanks for that , think I'll try new rads.
regards.
Paul

 

[D_Hailsham]

Does your boiler have the spare capacity to deliver the extra heat required by the larger radiators?

 

[tp123]

Yes, I had checked this earlier but thanks for bringing it up.