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<div class="moz-cite-prefix"><font face="Helvetica, Arial,
sans-serif">Hi Sacie<br>
I assume you have double-glazed low-e argon Pellas, with wood
frames?<br>
If you have condensation problems it is very likely too high
RH. I am curious about your comment that the RH is within the
recommended range.<br>
This could be ture, but is that recommended range might be 20%RH
or 50%, since I have seen both "recommended" for the Kansas
climate. Have seen some significant condensation on low-e Argon
filled windows in a large multi-unit building about 1.5 hr drive
from Kansas City which was reported to always be bad at this
time of year.<br>
Condensation like this tends to be worse early in the season as
the moisture from building materials is released. In my
airtight home this delay is very noticeable (eg RH is stubbornly
high until January I find), and I have to ventilate aggressively
during this time period to keep my RH within safe levels.<br>
As rough guidelines, when it is 30F outside, I would target
30%RH and when it is 10F, I would look for 20%RH. It takes a
while to ventilate down to those levels, but once you get there
it tends to stay.<br>
<br>
PS I have triple glazed foam filled fiberglass framed windows.
Condensation can be made to occur on these rather high
performance units merely by letting the RH ride up to, say, 50to
55% during 30F nights. The condensation quantity is small but
totally visible.<br>
PSS Bob's claim that windows leak outward in cold weather is not
true. It is often true for the second storey of homes, but
rarely true for the 1st floor of 2 stroey homes and almost never
true for windows on the windward side during windy weather.<br>
<br>
<br>
<br>
</font>
<div class="moz-signature">Dr John Straube, P.Eng. <br>
<a class="moz-txt-link-abbreviated" href="http://www.BuildingScience.com">www.BuildingScience.com</a></div>
On 12-10-28 1:20 PM, Sacie Lambertson wrote:<br>
</div>
<blockquote
cite="mid:CAM6L0t4dz+GbamEYBVidUVg4Xvy2cNtv5HsEP+=uzGx=7Uiunw@mail.gmail.com"
type="cite">On Sun, Oct 28, 2012 at 10:36 AM, Bob klahn <span
dir="ltr"><<a moz-do-not-send="true"
href="mailto:Home-NRG@dnaco.net" target="_blank">Home-NRG@dnaco.net</a>></span>
wrote:<br>
<div class="gmail_quote">
<blockquote class="gmail_quote" style="margin:0 0 0
.8ex;border-left:1px #ccc solid;padding-left:1ex">
Lance,<br>
<br>
One guideline that has been implied but not stated in any
reply I've read is that whatever approach you choose, the
innermost pane must be the air-tightest to limit condensation.
The old "rule of thumb" was five times tighter than
subsequent panes, if there is any leakage. This allows any
leakage (drying) to be to the outside.<br>
</blockquote>
<div>Re Bob's note on tight windows, we're now moving into the
winter heating season. Our windows are starting to condensate
at the base on the inside. Many of you have suggested this is
the penalty of winter. Isn't there anything I can do about
it? With the windows I have? Or, are there windows out there
that don't condensate in the winter? Are there windows that
don't leak cold air to the inside from the outside glass per
Bob's dictum? Or is this not a matter of tightness, but
rather of the differences in temperature?<br>
<br>
thanks, Sacie<br>
</div>
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<br>
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