New Radiators

[sandmaster]

We are modernising our house. Friends tell me modern radiators give out more heat than the old pressed steel radiators from the 70s that we have. I wonder what the experiences of fellow Answerbank members are?

[Old_Geezer]

Whilst I've no comparison experience I'd have my doubts. Power in = power out. I can see that one radiator design might heat up faster than another, but once it's done that surely they'd heat the same ?

[Kidas]

Some of the newer ones have heat-transfer vanes on the back.

Radiators work by heating water in the boiler. The water is pumped into the rads. As the water heats the metal rad, that energy is transferred into the room

A rad that looks like a slab of metal will transfer heat from that surface.

Add some thin vanes across the back and you can increase the heat transfer into the room significantly.

It means you can get away with smaller radiators.

[Garaman]

Modern radiators should be more efficient than old ones. They should have better water channelling to ensure water flows better, and ensure that the water heats more of the metal surface than the old ones did. The argument over which type of material hasn’t really changed:

Cast iron take quite a while to heat up but hold their heat well when the heating is switched off.

Aluminium take no time at all to heat up, but equally take no time at all to cool down when the heating is switched off.

Steel are somewhere between the two.

I put aluminium ones in our last upgrade and we are quite happy with them.

[The Builder]

Yes, modern rads do tend to be more efficient than older ones. They're often classed as "high output".

[sandmaster]

Thanks everyone. It obviously comes down to surface area and the vanes in modern radiators seem to be very effective. My old double radiators are not so effective and I can only guess that it is because the two inner surfaces are so close together. Garaman's remark re material is true. The quicker they warm up the quicker they cool off. But of course the heat has been transferred into the room.