Hi - I'm looking for papers where people have measured window performance
before and after retrofits, such as interior & exterior storm windows, and
weatherstripping, caulking, and sealing. Ideally papers that include air
leakage testing pre and post retrofit and u-value and shgc information.
Thanks!
Morgan Heater, P.E.
Hey Morgan:
As important as those measurements are the numbers that count are
comparative energy usage and comfort. Those are the measures of true window
'performance' in my opinion. A 50% decrease in air leakage may or may not
significantly impact energy usage and/or comfort. We have been involved in
a number of window retrofit projects and in the real world what they save
and occupant comfort are what has meaning AND VALUE.
I urge you to at least include, and I believe they should be the principal
items, actual energy comparative usage information and comfort. I feel that
it is a fallacy that there is a direct straight line meaningful and
impactful relationship between air leakage, u-value, and shgc, and, actual
energy usage and comfort except in the most gross sense. Location, use,
individual window differences that do not show in any of those reported
measurements, and, installation our experience shows as more important.
Thanks,
Andy Hoover