Replacing an old radiator with two smaller ones

[Alan H]

I have an old type 21 (600 mm by 1400 mm) that is against a wall I'd like to put furniture against, so I'd like to move it. There is no room to just move it along the wall so I was thinking of replacing it with two smaller ones on either side of the adjacent corner of the room. I guess the old radiator was probably just under 2 kW and I have room to put one 600 mm by 600 mm and one 600 mm by 700 mm type 22 radiators - I think they would give me sufficient heat output at just over 2 kW. Each would have its own TRV and I'd put them at the sides furthest away from the corner to minimise one radiator affecting the other's TRV. The plumbing looks straight forward - I'm a reasonably competent but occasional DIYer.

Does that sound reasonable? Any tips or things I should look out for?

 

[Old Account]

Hello Alan,

I am particularly not a big fan of installing a rad on walls without windows especially not opposite the window walls. There would be no convection if you know what it means. Ideally you will need to put the rads under the window. However, if you want to split the big rad into 2 smaller ones that's fine as long as you get the same heat output.

 

[Alan H]

Hello Alan,

I am particularly not a big fan of installing a rad on walls without windows especially not opposite the window walls. There would be no convection if you know what it means. Ideally you will need to put the rads under the window. However, if you want to split the big rad into 2 smaller ones that's fine as long as you get the same heat output.

Thanks for that.

The room is a living room that has a wide arched opening into what was once the outside wall but that now leads into an extension, so there are no windows in that room!

 

[ShaunCorbs]

Hello Alan,

I am particularly not a big fan of installing a rad on walls without windows especially not opposite the window walls. There would be no convection if you know what it means. Ideally you will need to put the rads under the window. However, if you want to split the big rad into 2 smaller ones that's fine as long as you get the same heat output.

Convection will still take place

 

[ShaunCorbs]

Op sounds ok

Do you know the pipework size ? Eg 10mm or 15mm etc

 

[Alan H]

Op sounds ok

Do you know the pipework size ? Eg 10mm or 15mm etc

I can see the main 22 mm pipes under the floor from the boiler but teed off that is 15 mm pipework that had been used to connect to a radiator in the extension that was removed decades ago, so I'll connect to that. Bizarrely, gate valves have been used to stop the pipe ends!

 

[ShaunCorbs]

15mm will be fine for two rads

 

[Old Account]

Convection will still take place

Not as much and not as efficient

 

[ShaunCorbs]

Not as much and not as efficient

Yes it will

 

[Alan H]

15mm will be fine for two rads

Thanks, Shaun. Good to know.

Not as much and not as efficient

I have no choice because there are no windows so all I need to do is replace the heat output of the one radiator with two smaller ones (and by making them type 22 rather than type 21 - and I will actually be increasing the kW available slightly). They will be nearer the arched opening to the extension so a bit nearer where the colder air will come from - I think that's the best I can do in the circumstances.