Important Window
Terminology
- Solar Heat Gain Coefficient
(SHGC)
-The fraction of solar heat transmitted thru window
-A SHGC rating of 0.40 means that 40% of the total solar heat is transmitted
through the window
-SHGC the most important criteria for Texas windows
- U-factor
-The measure of rate of heat exchange due to indoor/outdoor temperature difference
(Btu/ft2-hr-ºF) U is the inverse of R-value
-One ft2 of window conducts 5-10 times the heat of 1 ft2
insulated wall
-Less critical than SHGC for most of Texas
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