Will blinds improve a triple glazed window in winter? Merged

[Vortex2]

We have massive triple glazed windows on our eco house.

Being in the middle of a field we haven't bothered with roller blinds or curtains.

Would adding these help with insulation in winter?

[clv101]

Can't hurt! But doubt it would make a big difference, the internal skin temperature of your triple glazed is already high enough to mitigate drafts sitting near it etc.

[adam2]

Yes but only slightly.
Adding a blind or curtain to a triple glazed window might be compared to adding a lightweight cotton sheet on the top of a bed already made up with several thick wool blankets.
Warmer ? undoubtedly, it is basic physics. Noticeably warmer ? probably not.

I would still add curtains or blinds, as much for privacy and security as for warmth.
I appreciate that due to the remote location, that privacy might not be a significant concern under normal conditions. But during an emergency, do you really want the baddies to be able to watch your every move ?
Behind closed curtains, you can load firearms and make other defensive arrangements, unseen.

[BritDownUnder]

From what I can find on the internet a reasonably insulated wall is still a far better insulation material than even an argon filled triple glazed window. Windows tend to be given U values and other materials given R values just to confuse you.

I suppose your window has some kind of infra red reflecting coating but a good thick curtain will still block more radiative heat from escaping than no curtain.

Not sure what the draughts or the window being cold to the touch.

As Adam said, you never know who is watching from the edge of that field.

[kenneal - lagger]

A close fitting heavy lined curtain adds the equivalent of an extra pain of glass so even though it will not have a significant effect on comfort it will save heat loss through the window. As BDU said a wall has a considerably lower heat loss than a window and could have a u-value of 0.1 whereas a window would be 0.6, so six times the heat loss. If you can reduce that to only three or four times the heat loss over a large window by the addition of heavy lined curtains that will make a difference. The use of Millium, an aluminised lining fabric, that would help.

Then there are the security issues as well as others have mentioned.

[Vortex2]

Hi,

Can the thermal performance in cold weather of triple glazing be enhanced by adding blinds or curtains?

[adam2]

I would say yes, but only marginally.
Adding insulation will in all common cases reduce heat loss, but if this heat loss is already small, then the gain will be modest and perhaps not noticeable.

[kenneal - lagger]

As I said above the window, even a triple glazed window, will lose heat at six times the rate of an equivalent wall. Adding an extra layer, assuming it is a good thick airtight layer, will reduce that heat loss by anything up to a third. How much that reduction is will depend on the size of the window.

I would certainly use heavy lined curtains in my house.

[Vortex2]

Thnaks for the merge - I'd forgotten about that ealrier post ... doh ...

[Lurkalot2]

As i understand it adding a pelmet to curtains help with heat saving. Most curtains and fittings seem to be aimed at privacy rather than any insulation effect. As such they are subject to thernosyphoning where warmed air is drawn in at the open top , cools against the glass and exits at the bottom. Addind a pelmet to close the top helps to reduce the effect and i would assume curtains as close to the wall as possible would help.

[BritDownUnder]

I did some research myself and I found one article on the net that said that a pelmet doubled the effective R value of the window. Believe it or not if you want. Have a look yourself.

[kenneal - lagger]

I'm quite happy to believe that. It's probably why the first one was fitted centuries ago!

[Lurkalot2]

Also has the added advantage of blocking out light leakage so Adam doesn't have to load his guns in the dark..