Re: GBlist: condensation question

[Speireag Alden <Joshua.M.Alden.91@alum.dartmouth.org>]

Sgrìobh KG:

>When my double-glazed windows are uncovered (no curtains), I see very little
>condensation.  When the curtains are closed, however, I see more -- even if
>the air feels dry.

     When they aren't insulated, they stay warmer, and so the latent 
moisture in the air doesn't become suddenly colder and condense.  If 
you insulate them somewhat, the panes of glass are colder and draw 
moisture out of the air more aggressively.

     Best solution:  nighttime exterior insulated shutters. 
Guaranteed better overnight thermal performance, and no condensation 
at all.  Problem:  requires manual opening and closing, even in snow 
country.

     Conventional solution:  blow some warm air across the window to 
warm up the glass so that it won't grab the moisture out of the air. 
Problem:  the glass doesn't keep the heat.  It transmit it to the 
outside, so you are blowing heat (and therefore money and resources) 
right out the window.

-Speireag.
-- 
Speireag Alden, aka Joshua Macdonald Alden
Usually found somewhere in the wilds of New Hampshire.
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