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<DIV><FONT face=Arial size=2>I've been living the test for over 25 years-at
first I had no window insulation, and noticed large heat losses, then I built my
insulating shades, and discovered much less heat loss. Thank you for admitting
that testing trumps theory, some folks just don't seem to get that. Doug 25
years of comfortable living in a direct gain solar home. </FONT></DIV>
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<DIV><SPAN class="PreviewMsgText visualIEFloatFix" id=ucPreviewMsg_lblMessage><PRE>Date: Wed, 17 Nov 2010 14:27:23 -0500
From: RT <ArchiLogic@yahoo.ca>
To: greenbuilding@lists.bioenergylists.org
Subject: Re: [Greenbuilding] moveable insulation
Message-ID: <op.vmbxnxzk4f5a3n@owner-b0bdc4ac6>
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On Wed, 17 Nov 2010 13:28:31 -0500, Doug Kalmer <sunart@netease.net> wrote:
> I doubt there are even a couple of ounces of water condensed on a window.
The amount of condensation depends upon a number of variables:
(i) How friggin' cold it is outside ( ie If it's only minus 20 or so,
maybe not so much condensation. If it's minus 30 -minus 50 then you're
going to have audible drips and ice build-up of a cm. or more.
(ii) The air-tightness of the construction. An air-leaky house would
have dry air in winter. Minimal condensation
etc.
The point is, this thread started with the suggestion that the
knuckleheads who were using rigid insulation to make insulating shutters
were stuck in the Dark Ages and that using bubble wrap to make
easy-to-operate roll-up shades was the enlightened approach.
Chances are those kNeanderthal Knuckleheads were using rigid insulation
because (i) it can be placed right up against the glass to eliminate the
convective airspace that would exist with roll-up shades and (ii) the
rigidity of the panels makes it easier to create effective edge seals to
minimise the entry of moisture-laden warmed air into the glass/insulating
shutter interface thereby minimising the potential for condensation
problems.
I don't have a problem with roll-up shades made out of bubble wrap.
But I would doubt that they provide anywhere near the R-value that
bubble-wrap manufacturers claim.
The fact that condensation exists in your (Doug's) situation merely means
that the shades are preventing movement of warmed air against the glass
allowing the mositure in the air to reach the dew point.
The same thing could be accomplished by placing a sheet of newspaper over
the opening.
Or course, I could be full of hooey. Only a test will tell the troot and
that would be easy to do.
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