Reading Energy-Efficient Window Labels: A Quick How-To

With the weather beginning to heat up, energy-efficient windows are going to be essential to keeping your home cool.

But how do you know which windows are best?

The National Fenestration Rating Council includes labels on windows to show each window’s performance. These labels indicate several performance factors, but without the proper background, they can sometimes be difficult to read. Here’s a quick summary of the label so you know what to look for in your replacement windows this summer.

Energy Ratings – 

• U-Factor. This number indicates how well the window is insulated. The lower the number, the better insulated (and more energy-efficient!). Anything under .30 is considered to be energy-efficient, but at Aspen, we go above and beyond. Our replacement windows have a .24 rating – so we’re better than just being energy-efficient!
• Solar Heat Gain Coefficient (SHGC). SHGC indicates how much solar heat is being let in by the replacement window. The lower the number, the less heat being let into your home.

Other Ratings –

• Visible Transmittance. This number is an indicator of how much light is being let into your home by the replacement window. The higher the number, the more light being allowed into your home.
• Air Leakage. Like our last rating, air leakage describes exactly that; air leakage shows the amount of air passing through the window. Remember – this number is not always shown on a NFRC label.
• Condensation Resistance. This number indicates the resistance of your window to condensation buildup. In this particular case, the higher the number, the more resistant it is to condensation buildup. However, like air leakage, this number is not always shown.

If you’re interested in learning more about our replacement windows, view pictures of our past window projects. You can also click for a free estimate from our team!