Sat. Dec 5th, 2020

Understanding NFRC rating data is important, when picking window replacements for Colorado climate. Because of the fluctuating temperatures throughout the year, maximum energy efficiency can only be achieved through understanding the data specific to your area.

Energy saving windows are rated based on four properties, U-factor, Solar Heat Gain Coefficient (SHGC), Visible Light Transmittance (VT), Air Leakage, and Condensation Resistance. All criteria for energy star windows are based on these properties.

NFRC Ratings for Colorado

U-Factor SHGC Air Leakage
Windows: U ≤ 0.30
Windows: U = 0.31
Windows: U = 0.32
Skylights: U ≤ 0.55
No requirement
Windows: SHGC ≥ 0.35
Windows: SHGC ≥ 0.40
Windows: AL ≤ 0.30
Skylights: AL ≤  0.30

NFRC Rating Lable Example for Colorado

Here is what a typical NFRC rating label on a window suitable for Colorado climate. By using the table above, you can see that this window’s U-factor that is 0.30, is consistent with the U-factor table requirement of (Windows: U ≤ 0.30).  The same for the Solar Heat Gain Coefficient (SHGC) rating, which in this case, the window rates at 0.35, and requirement in the table above is (Windows: SHGC ≥ 0.35), and the Air Leakage which shows 0.2 is consistent with the table requirement of (Windows: AL ≤ 0.30). Visible transmittance can vary according to preference.

 

 

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