new windows don't seem to matter for keeping cold out (floor, how much)

[ovi8]

We had a ranch that we put a new 2nd floor on top with majority Andersen 400 double-hung windows. These are the better ones according to their site save for "architectural" I think. Many sites say to replace "old vinyl windows" (other than wrapping them in plastic) to keep drafts out, but we're finding it doesn't matter whether it's new windows or old. We can still feel cold air "coming through" the panes and my unscientific opinion is that it's not that much better than the old windows downstairs. What has been your experience?

I'd love to hear any science behind it - such as how much that lingering cold air is better than an actual draft coming through, etc. Also how much worse is having just batting insulation in the ceiling as opposed to sprayed cellulose? Not sure what R-value they put in the attic floor, just the walls all around. There's always %s being thrown around.

[rasengan]

I have good windows too but I noticed when the sub-zeroes temperature hit last week it just didn't matter. I could feel the cold air through the panes and I even saw a little bit of ice forming from the condensation in our house.

[Linda_d]

Glass is simply not as good an insulator as wood walls filled with insulation. Even double glass insulated windows allow in more cold air than the nearby walls. I mostly abandon my little 12 x 12 sunroom during the coldest part of winter even though it's heated because it's chillier than the rest of the house because of all the windows and the skylights.

[mmyk72]

same here. When it's 30-40's, I can just slightly feel the cold from the outside. But when it gets to 20's and below that, especially with the unusual single digit temps lately, the cold thru the glass part of the window was very noticeable. Mine are double-pane vinyl.

[Pitt Chick]

Bitter cold will come through glass... no getting around that.
Try some thermal drapes over those windows.

[Billy_J]

Good windows will be rated "Energy Star".

Then a single pane of glass will easily transfer cold or hot.

But a double pane Energy Star window is filled with a special gas in-between the panes, and that gas is a poor "thermal conductor". So much less transfer of heat / cold as compared with a single pane window.

If the previous or other windows were double pane Energy Star windows, then you will probably not notice much difference.

Note there are triple pane windows and windows designed for Canada / Alaska. You can see these on a window manufacturers web site. Or search for key words like insulation, R-value, windows, etc. and the word Alaska. They do all sorts of special things up there due to the extreme cold.

Your best option may be to just install heavy drapes.

[RyanR]

If drapes aren't your thing and you only need something for these cold snaps, consider something like moving blankets. They don't let much air pass through (basically, you can barely blow through them). I just use thumb tacks to hang them.

There's varying "weights" on the moving blankets. If you go with the heaviest, they're a bit heavy to hold up with tacks. The ones you get at places like Home Depot or Lowes are fine.

[sullyguy]

Originally Posted by Billy_J

Your best option may be to just install heavy drapes.

Or something.

Here in Northern Virginia we have double pane wood windows - they're fine as they are but leak some wind around some parts sometimes.

However, during this particularly nasty cold spell there is NOTICEABLE cold streaming from them just because they're supercooled surfaces.

So we close our vertical blinds and both immediately and over time notice the house being considerably warmer.

But...sigh...darker, too, of course.

[James1202]

We have new double-pane wood...all wood...windows (Marvin Ultimate). The interior pane of glass gets cool but there are no drafts or coolness near the windows.

[nybbler]

You know you have to close the windows, right? :-)

Seriously, a single-pane 1/4" piece of glass has an R-value of about 0.9. An Anderson 400 has an R-value of about 3.3. So it's like having about an inch of glass between you and the outdoors... that's better than 1/4 inch of glass, but it's nothing like having an insulated wall.