[Greenbuilding] moveable insulation

[RT]

On Wed, 17 Nov 2010 13:28:31 -0500, Doug Kalmer <sunart at 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.



-- 
=== * ===
Rob Tom
Kanata, Ontario, Canada
< A r c h i L o g i c  at  Y a h o o  dot  c a >
manually winnow the chaff from my edress if you hit "reply"
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