Advice required regarding changing radiators

[nrwilliams]

Hello all,

I have two rooms in my house which by my calculations need 5000BTU radiators.

They currently have old double convector radiators measuring 90cmx40cm. During last winter these rooms would remain quite cold. The heating system is in good order, the boiler is new and sized correctly.

I cannot decide whether to just change the rad for new one of the same size, I have found 90x40 rads with an output of 4100BTU which I could fit without altering the plumbing under the floor boards or whether to purchase larger 5000BTU radiators and have to take the floors up to move the plumbing.

Does anyone have any experience of this? I have no reference as I don't know the output of the current radiators, does 1000BTU make that much difference?

I have dealt with insulation, double glazing, draughts etc and just don't want to go through this winter with the rooms remaining chilly.

Thanks in advance for any input you may have.

Neil

 

[gremlin16]

1000 BTU = 0.293 kW

 

[expertgasman]

After having gone to the trouble of sizing and considering insulation etc, why on earth would you downgrade from your calcs by 25%?

Having said that, new radiators give considerably more heat per sq ft than old. But your room is cold, so clearly rads are undersized, assuming they get uniformly hot.