[Greenbuilding] Windah tahk (was Re: passive house in NY)

[Reuben Deumling]

I don't doubt that my crummy aluminum storm windows that live about 1-1/2"
(top sash) and 3" (bottom sash) from the 120 yr old single glazed double
hung wood windows in my house are as you say far from perfect when it comes
to thermal performance. I will say, though, that the combination is markedly
better than without those crummy storm windows. I've fiddled with my IR temp
gun on cold nights pointing it at these windows, with and without storms,
from inside and out, and found satisfying (to me) differences, the issue of
the IR+ glass emissivity notwithstanding.

I too know of therrmopane windows installed in 1967 on the Oregon Coast
(pretty unfriendly climatic conditions) which have still not failed. The
trouble is, said house has had three fail after ~24+ yrs. So the risk of
failure I think is real in the time frames discussed here.

In Germany (very different windows than we are used to in the US), a two
sashes locked together method was common for a few decades in the mid-late
20th Century. I've lived in houses with those windows and don't recall any
condensation issues. Distance between inner and outer glass I would estimate
to be close to 1".

I admit I didn't follow all of John Salmen's point about relative failure
rates. Are you saying, John, that the window housing is also only made to
last 25 years these days? Because my window maker doesn't look at his
products that way. I am under the impression that he is shooting for 80-10
years+.

Can you say more about the last point below: "so we are looking at houses
that essentially collapse beforee there is any economy in place to maintain
them"? Got any references? I'm really interested in/concerned about this
sort of thing.

Thanks all.

On Thu, Oct 27, 2011 at 9:12 PM, JOHN SALMEN <terrain at shaw.ca> wrote:
I do think the manufacture has improved with better sealants but the
manufacturing industry has also taken advantage of that to cut costs so...
we are hopefully looking at 20-25 years which only means that the glazing
will potentially last as long as the window housing (frame/hinge/weather
stripping).  is a huge expense for house maintenance and typically not
factored in. The housing industry is geared to that 25 year number for
substantial renovation/rebuild on all components but housing cost and
construction/financing economies are not so we are looking at houses that
essentially collapse before there is any economy in place to maintain them.


On Sat, Oct 29, 2011 at 7:31 AM, RT <archilogic at yahoo.ca> wrote:

>
> If condensation between the single-glazed, old windows and (outside) storms
> has never occurred, I'd venture that it's likely because the storms don't
> provide a very good air seal, allowing vapour between the panes to escape to
> the atmosphere before condensation occurs.
>
>
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