[Greenbuilding] R20 window insulation?

[Corwyn]

Some thought on R-20 Window shutters:

• You might try the foam weatherstripping I use on my interior storm 
windows 1/2" x 1/2" open cell foam compressed to 50% of that upon 
insertion in the window frame.

• R-20 is impressive when it is actually IN the window.  If you  are 
using them for less than 12.4 hours per day, you will probably be better 
off with an interior storm window (see 
http://www.greenfret.com/projects/storms.html ) which provides a lower 
R-value, but present all the time.

• If you aren't the sort of person who will put them in every night, 
then you might also be better off with something you only need to change 
once a season.

• For north (Pole-ward) windows where the shutter is in all winter, the 
shutter are VASTLY better option.  (but...)

• Make sure they fit very snugly in the window frame, and that no 
moisture is accumulating behind them.  If air circulates through the 
space between the shutter and the window, you have merely created heat 
pump and a water pump.

Thank You Kindly,

Corwyn
-- 
Topher Belknap
Green Fret Consulting
Kermit didn't know the half of it...
http://www.greenfret.com/
topher at greenfret.com
(207) 882-7652