Why are radiators almost always on outside walls and under windows

[Mynameisthecatwhogotthecream]

It's always puzzled me, surely it would be more efficient and less heat would be lost if they were on internal walls and away from windows, is it because that's what always been done or is there a reason for it?

Helps with furniture placement as you wouldn't usually put a wardrobe under a window say.

Mine is on an internal wall not under a window.

I'm saving up to get it moved, it's a pain and makes the whole wall unusable for a sideboard or bench.

I wish my radiators were under windows, they are all on internal walls. Having the. under the windows would make so much more sense in terms of placing furniture.

It is to counteract the cold air coming into the room.

I had a house once where the radiators downstairs were on the opposite wall to the window, which were also internal walls. The downstairs was always cold and the radiator placement was suggested by many as the reason why.

I thought it was to warm the cold air that escaped from outside into the room?

Isn't it to negate the draught from windows? So any cold from the windows is overtaken by heat

From my understanding it's the most efficient place as the heat pushes outwards and then rolls back. I don't think I'm explaining it very well, but the heat moves forward from the radiator not up.

My physics teacher taught us it was the best place for them, as the warm air rises and heats the cool air coming in the window, which then circulates round the room. If the radiator was opposite the window, he said that by the time the warm air got to the window, it wouldn’t be warm enough to heat the cold air coming in and you’d get a cold draught around your feet.

No idea if he was right, though!

@Pumpkinstace

Mine is on an internal wall not under a window.

I'm saving up to get it moved, it's a pain and makes the whole wall unusable for a sideboard or bench.

I have no idea about these things. But what about a vertical one?

I have mine on internal walls, but I have double glazing, so it's fine

Here you go OP
www.onlyradiators.co.uk/blog/how-to-guides/where-to-position-a-radiator-in-a-room

We renovated and have put radiators generally speaking in the coldest bits of rooms or where they can warm zones

It counteracts the cold air coming from outside...

It is to heat cold air coming in to the room by convection.

I have always wondered why they weren't called convectors because they do not radiate heat at all.

They are convectors not radiators.

Back in the day, many people who had central heating didn't have double glazed windows, so it was basically placed under the window to warm draughts, as heat rises the theory was the heat would blanket the whole window, thus making the room warmer.
It's also convenient as many people didn't tend to put furniture directly in front of the windows.

So my cat can snooze on the window sill in near-tropical luxury.

It helps with furniture placement and the air circulation round the room.

Curtains / blinds can make a huge difference to the cold air at a window.

Mine are all on internal walls.

Helps prevent mould. Only one of my rooms has the radiator under the window...it's the only room that doesn't get mould. I wish all the rads were on outside walls/under windows. Would make life a lot easier!

Convection. In a small room it's less essential, and the newer style with the slots in the top are also better at pushing the warm air around the room.

I hate radiators, I think they're an utterly stupid design no matter where they're placed tbh.

The only one I have on an outside wall is the one in my bedroom, which is the only room that never seems to get warm.

I've got 15 radiators - only 2 are on outside walls.