[Greenbuilding] [BULK] Re: Window insulation

[Lawrence Lile]

The window quilt manufacturer claims about R5.  I am skeptical that
something so thin can achieve this, it's about an inch thick so that
puts it up there with foams for efficiency if their claims are correct.
I haven't seen anything to counter this claim, it would be interesting
to measure it. I'd bet it is closer to R4. 

 The window quilt material has two layers of insulating fluff around a
central layer of reflective mylar, backed with a canvas-like material.
You sew (or in my case apply fusible webbing with a steam iron) your own
layer of fabric on the front side.  The manufacturer gushes about how
easy they are to make, but I found them tricky, and my old Singer would
not sew the thick material at all.  Fusible webbing ("steam-a-seam")
comes to the rescue.  

Window treatments accomplish three things - first a simple increase in R
value from about 2 for a double glazed window to R6 or R7.  Second it
can produce a decrease in infiltration if you have leaky windows.
Third, it produces a surface on the inside of the house that is much
warmer than a bare window.  If your body is radiating to a frosty
window, you feel colder than if your body is radiating to a room
temperature curtain.  This can work even with thin curtains, you may not
see much difference in your heat bill with a conventional curtain but
the room will feel warmer due to radiant effects.  

It's recommended to look for a window treatment system that adds at
least R4 and seals tight around the edges to prevent convection heat
loss. 

Lawrence Lile, PE, LEED AP
Project Solutions Engineering
-----Original Message-----
From: bilrob at silcom.com [mailto:bilrob at silcom.com] 
Sent: Wednesday, September 26, 2007 7:40 PM
To: Lawrence Lile
Cc: Greenbuilding at listserv.repp.org
Subject: [BULK] Re: [Greenbuilding] Window insulation
Importance: Low

So how much do you gain in measurable (R or U value)terms by using
window 
quilts?
Bill Robinson
Train2Build


Quoting Lawrence Lile <LLile at projsolco.com>:

>  
> I've been playing with window insulation lately.  
>  
> First, I have tried the classic R-Max alumimum foil clad polyiso
board, duct
> tape on the edges, painted on the interior, force fit between the
wooden
> trim.  It's cheap, effective, and ugly. 
>  
> You can always dress up the force-fit Rmax with a covering of your
favorite
> cloth, a little less cheap, still effective, and not too ugly. 
>  
> I am using window quilts  http://www.warmcompany.com/wwhdwr.html  on a
few
> windows.  These are very nice looking, very efficient, and easy to
move up
> and down by a string just like a regular window shade.  They take a
lot of
> effort to put together.  They are also very expensive.  
>  
> A big portion of the cost of the warm window quilt is magnets.  They
use a
> magnetic strip to get a good seal around the window.  
>  
> I noticed an interesting fact:  I have sheetrock returns around the
windows
> (not wood trip like most people) because of extra thick walls.  The
sheetrock
> returns feature a metal corner bead, which is common in sheetrock
> construction.  this metal corner bead will hold a magnet!  
>  
> I could get rid of half the magnets in the warm window quilt system,
or
> install magnetic strips ont he backs of foam panels.  I believe that
magnetic
> foam panels would be a lot easier to put up and take down than force
fit foam
> panels, and should last a lot longer.  I am going to try this after I
get
> done with my current Window Quilt.  
>  
>  
> So the moral of this story is, use sheetrock returns on your windows -
and
> make sure they use metal (not vinyl) corner beads, this will help you
use
> magnets when you go to install moveable window insulation.  
>  
> --Lawrence Lile
> _______________________________________________
> Greenbuilding email list
>      Environmentally-preferable design, construction, building
elements
> List info:
>
http://listserv.repp.org/mailman/listinfo/greenbuilding_listserv.repp.or
g
> List email: Greenbuilding at listserv.repp.org
> Managed by BuildingGreen, Inc. http://www.buildinggreen.com
>       publisher of Environmental Building News and GreenSpec
> Hosted and archived by REPP / CREST http://www.crest.org
> To get on the list:
>
http://listserv.repp.org/mailman/listinfo/greenbuilding_listserv.repp.or
g
>   or
mailto:greenbuilding-request at listserv.repp.org?subject=unsubscribe
> To get off the list:
>
http://listserv.repp.org/mailman/listinfo/greenbuilding_listserv.repp.or
g
>   or
mailto:greenbuilding-request at listserv.repp.org?subject=unsubscribe
>