home insulation - insulating paint?

calmgirl

also gromituk my heating is on I have just gone outside my windows are cold my neghibours are warm we both ahve double glazing fitted in the same week by the same bloke

GreenNotM

Windows provide a cold heat sink into a room and generate cold down-drafts... with a radiator by a window it is being cooled and you are heating an outside wall. Long curtains over windows and radiators allow the heat to travel straight to the glass, not into the room - shorter curtains just allow the cold downdraft. The mass of cold air outside is greater then the mass of warm air inside - so it is the cold window cooling the room -


Rads were put under windows as it was convenient, when rooms were full of sideboards chairs etc ... it is best to have long curtains to stop the downdraft.

It is possble to put PIR board between the rafters of your roof - but allow 50mm gap for ventilation use nails or studding as depth stops. The new insulation buzz word is "cold bridges" so the wooden beams in your loft are allowing heat str8 into the loft space - these need to be coverd with insulation.

this http://www.celotex.co.uk/appl/PDF/Product_Summary.pdf uses the more correct building terms and shows how to double insulate the rafters - which you should consider if you use the loft for storage or have your cold water tank there.

gromituk

GreenNotM wrote:

Rads where put under windows as it was convenient, when rooms were full of sideboards chairs etc ...

Possibly, but also to reduce the downdraughts. After all, modern rooms aren't exactly denuded of furniture, are they?

The downdraught problem will be less severe than it was, because of double glazing. That might explain any trend away from radiators against outside walls. I agree that putting radiators on an outside wall wastes heat through that wall, so there should be some insulation behind the radiators.

gromituk

calmgirl wrote:

All i know is that our next door neighbour lives in an identical house to us all their rads are under windows, ours are on the walls and they pay much more for their gas than we do. (both have 3 kids) we also cook with ours they have electric cooker.

* Do you both have the same type and age of boiler?
* Are both houses heated to exactly the same temperature?
* Do both houses have the same degree of draught-proofing?
* Do both houses have the same type and thickness of loft insulation?
* Are both houses heated for exactly the same hours?

I can guarantee that the answer to at least one of those questions will be no, and that will dwarf any difference between the position of radiators.

bunking_off

GreenNotM wrote:

Rads were put under windows as it was convenient, when rooms were full of sideboards chairs etc ... it is best to have long curtains to stop the downdraft.

From Jeff Howell's column in the Sunday Telegraph last week;

"Keeping external walls above dew-point temperature is vital to prevent condensation. Radiators are also often sited below windows, one purpose of which is to dry out any dampness caused by rain running off the glass and tracking back below the sills. Stopping radiators from warming walls might result in money having to be spent on repairing decorative damage."

Don't know if there's any truth in this, just reproducing what he said...

gromituk

Hmm - never heard that one before. Rain should not track below the cills if they are designed properly.

GreenNotM

gromituk wrote:

Hmm - never heard that one before. Rain should not track below the cills if they are designed properly.

Isn't that what the groove under windows sills is for - to make the water drip. Can't see the difference between rain running down brick work and glass - still the same collection area..

gavinp

I bought a couple of rolls of this "reflecting tin foil wallpaper" which is fitted behind our radiators located under windows and it does seem to have helped:

http://www.screwfix.com/app/sfd/cat/pro.jsp?id=10612&ts=18930

Thanks

Gavin

calmgirl

gromituk

I have obivously have offended you in some way so im sorry othe rthean that


Cae yr Gig, saes bwlch

gromituk

Not at all. I'm just pointing out that your conclusion is a bit simplistic.