Radiator placement - where is the best position?

DTDfanBoy

DandelionPatrol wrote: »

The relative losses of external wall and window have no bearing whatsoever on the choice of internal wall vs external wall or window. They only come into play if the choice is between placing radiators on plain internal wall or under widows.

Of course the wall/window losses have bearing, the less well insulated the faster they will loose heat, if you stick the radiator on the external wall the wall temperature of that wall will be higher, hence greater losses through the wall and windows.

pendragon_arther

Plus the bricks on internal walls act as a storage for the heat generated, so will be warm for a while once the rad is off; as in storage heaters.

lstar337

Another factor here is that the OP has bay windows, so unless the windows are tiny, they will have to use those pathetic little radiators that are about a foot tall.

Ben84

Typically they're under windows. The idea seems to be that the heat loss from the window and any drafts will be hidden by the flow of hot air rising across the inside surface of the window. Double glazing will reduce the heat loss and drafts, but even good windows loose heat and will cool the air around them. I guess it depends if you want to keep the maximum heat in the house, or to have the most even heating in the house? Personally, I'm willing to loose a little heat if it's doing something useful, so I like the radiators under the windows. When the boiler is running, I really don't feel any cold from my windows, not even the really big ones. The few windows that don't have radiators under them are noticeable however, and I end up making less use of the space around them as I don't want to put chairs or beds near them.

lee111s

The advice about putting them under windows can't be that outdated, all new house builders place them under windows where possible.

Houses these days are super efficient, I doubt they're doing it without good reason.

DandelionPatrol

DTDfanBoy wrote: »

Of course the wall/window losses have bearing, the less well insulated the faster they will loose heat, if you stick the radiator on the external wall the wall temperature of that wall will be higher, hence greater losses through the wall and windows.

A statement of the undeniably blooming obvious, but it is a mistaken argument.

With an energy efficient house, the temperature on the inside of the outside walls is higher too, and much nearer the temperature of the surface of the inside wall. It is a clue that to achieve a level of comfort you need the room surface temperatures of the outside and inside walls to match as far as possible - in order to avoid heat transfer across the room. If there is heat transfer across the room and you are sitting in it, you will be sitting in a draft.

lstar337

lee111s wrote: »

The advice about putting them under windows can't be that outdated, all new house builders place them under windows where possible.

Houses these days are super efficient, I doubt they're doing it without good reason.

As already stated, I live in an EPC A rated house, and while it is possible to put the rads under the windows, they didn't. All the rads are on internal walls. Your statement in bold is false.

Other than leakey old windows, the only other reason to put a rad under a window is so that it doesn't tie up any useful wall space. Walls with windows are more or less wasted for storage devices, so you might as well stick a rad there.

CathA

We had a house with bay windows. The curtain track went on the outside of the bay window, so we had floor length curtains on the outside part, making the room 'square ' when the curtains were pulled, if you see what I mean? Our radiator was on the inside wall to the left of the bay window wall. All the other radiators in the house were in the usual place under the windows. HTH.

A_Frayed_Knot

I have had two places with bay windows and my mum also has a bay window - none of our homes have or had radiators at the window. As some have pointed out you can have long heavy curtains with thermal lining which I had - this keeps the room cosy when drawn in winter.

Think this all comes down to personal choice and what suits you and your room furniture layout best.

Just one word of warning though, and I know not all installers will be like this, but I do know of someone who wanted their radiator in the bedroom as you entered the door, they said it would be best behind the door - why? - because on the other side of the wall was the hall radiator, which meant easy installation for them - on the wall as you entered the door would have meant a whole lot more work for them, but its where the customer wanted it, they over ruled her.:(