Just going over the plans for some building work we are having done and the architect has specced the radiators under the dormers. Is there a reason for putting them under windows, and would they not be better on another wall which is better insulated above?

I think the traditional idea is that they warm the cold air next to the colder glass. If they were elsewhere then you’d have warmer and colder sides to a room. Convection of the warmed up air distributes the heat around the room to keep you cosy

you “lose” less wallspace for things – chairs, tables etc ?

As Cotic853

scaredy, that was my first thought, but what cotic says makes sense – same reason they have the heater blowers by the doors in shops?

Its to stop convection currents causing what feels like draughts. Rad under the coldest part of the room gives more even heat across the room – put the rad on the side opposite the window and air will ciculate around the room more. It is less efficient tho

Maybe you should have asked a building services/HVAC engineer.

The technical reasons for siting rads under windows are:

1 Heat is provided where it is most needed (i.e. at the point of maximum heatloss)
2 cold ‘negative’ radiation is countered at source
3 temperature gradient is less than if they were situated elsewhere
4 marking of a wall with dust carried in rising convection current is avoided.

HTH

Thanks folks.

If theres a draught coming thru a window then the colder air will drop into the building.. the heat under it will rise. mmmm.

Didnt you lot do GCSE/O Level Physics?

http://www.gcse.com/energy/convection2.htm

Didnt you lot do GCSE/O Level Physics?
Nope 😆

Helps reduce condensation as well.

They’re for cats: so they can sit on window ledges and warm their bums at the same time.

architects have specified radiators?

no underfloor heating? much more even warmth throughout the room(s) and allows greater ease putting furniture in the room…. no ‘cold’ spots or ‘hot’ spots in the room either.

You know it makes sense!