Curtains, windows and radiators

[Wendy]

What's the best way to arrange this?  Should the radiator be behind the long curtain, or should the curtain be short, and not cover the radiator?

My feeling is that radiators are put by windows to negate the cold airflow, and that it doesn't matter too much whether it's behind or in front of the curtain, because there's going to be air circulation there anyway given the gaps at the top and bottom of the curtain.

[urban_biker]

I would always go for a short curtain so that the heat of the radiator goes into the room rather than into the gap between window and curtain.

This is on the assumption that trapping the hot air behind the curtain just sends it out of the window rather than into the room.

Not sure that is 100% the case though - its just an assumption.

[nuttycyclist]

My view is that the bottom of the curtain should be about an inch below the top of the radiator, so that the curtain can be tucked behind the radiator when drawn.

That way the heat from the rad is forced into the room, not up the back of the curtain.

[Wendy]

Does it matter though, because you have a continual flow of cold air down the window surface and behind the curtain anyway?

[clarion]

My view is that the bottom of the curtain should be about an inch below the top of the radiator, so that the curtain can be tucked behind the radiator when drawn.

That way the heat from the rad is forced into the room, not up the back of the curtain.

I agree. 

While having a pocket of warm air between your curtain and the window might help a bit, you're constantly having to reheat that air as the energy is inevitably lost through the window.

You want your warm air in the room, not insulated from you by a thick piece of material...