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Energy Efficient
Glass Examples
(U-Factor and SHGC are approximate and will
vary depending on manufacturer and grade of glass.)
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ALUMINUM FRAME WINDOWS
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| Window
Type |
U-Factor |
SHGC |
| Single Clear |
1.25 |
0.74 |
| Single Tint |
1.20 |
0.60 |
| Double
Clear |
0.79 |
0.63 |
| Double Tint |
0.75 |
0.53 |
| Double
Tint Low-E |
0.54 |
0.32 |
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VINYL FRAME WINDOWS
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| Window
Type |
U-Factor |
SHGC |
| Single Clear |
0.90 |
0.60 |
| Single
Tint |
0.86 |
0.52 |
| Double Clear |
0.49 |
0.46 |
| Double Tint |
0.45 |
0.42 |
| Double
Tint Low-E |
0.36 |
0.28 |
U-Factor:
Also known as the U-factor or coefficient of heat transmission,
a measure of the rate of non-solar heat loss or gain through a
material or assembly. U-values gauge how well a material allows
heat to pass through. U-value ratings generally fall between
0.20 and 1.20. The lower the U-value, the greater a product's
resistance to heat flow and the better its insulating value.
SHGC:
The fraction of external solar
radiation that is admitted through a window
or skylight,
both directly transmitted, and absorbed and subsequently
released inward. The solar heat gain coefficient (SHGC) has
replaced the shading
coefficient as the standard indicator of a window's shading
ability. It is expressed as a number between 0 and 1. The lower
a window's solar heat gain coefficient, the less solar heat it
transmits, and the greater its shading ability. SHGC can be
expressed in terms of the glass alone or can refer to the entire
window assembly.
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