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Understanding Solar Heat Gain Coefficient

Preventing excessive heat gain is one of the primary tasks of high-performance windows and glazed doors. Renewal by Andersen® of Memphis, however, admits that not all fenestration products can do this job efficiently. To identify which ones can prevent most of the sun’s infrared light from entering your house, pay attention to Solar Heat Gain Coefficient (SHGC).

Understanding Solar Heat Gain Coefficient

What Is It?

SHGC measures a product’s ability to resist solar heat gain. It ranges from 0 and 1, any reputable window and door replacement specialist would advise you to go with a lower number.

Most of the sun’s light passes through the glass, but the National Fenestration Rating Council (NFRC) focuses on the entire unit. This non-profit also takes the heat transmittance occurring through the frame into account to come up with a more accurate rating.

What Is Ideal in Our Climate?

In Shelby County, the maximum SHGC to look for in replacement windows is 0.25. To successfully meet ENERGY STAR®’s requirements for the South-Central Climate Zone, though, Renewal by Andersen of Memphis recommends taking note of the U-factor too. Your chosen units must also have a U-factor of 0.30 or less for excellent energy efficiency.

When it comes to glazed doors with over 50% glass, the combination to look for is 0.30 U-factor (or less) and 0.25 SHGC (or less).

Why Choose Renewal by Andersen Products?

Renewal by Andersen of Memphis products bear the ENERGY STAR label, which indicates satisfactory energy ratings. Our standard High-Performance™ Low-E4® glass allows only 42% of the solar heat through while having a U-factor of 0.25. To reduce heat gain further, we recommend our High-Performance Low-E4 SmartSun™ glass, which only lets 28% of solar heat and has a U-factor of 0.24.

Made with Fibrex® material, our products do not expand and contract as much as most vinyl replacement windows due to extreme temperature fluctuations. The rigid frames of our windows render them weathertight for decades and therefore more reliable and energy-efficient over time.

To learn more about our made-to-order products and start-to-finish service, call (901) 779-1178 to schedule your free no-obligation consultation with us.


"Great job, timely and good service."

Bobbie Maxwell
Jul 25, 2022

"We are absolutely pleased with our decision to have our windows replaced by RbA. The in-home sales was pleasant and no pressure. Since each window is custom made, it did take several months. The wait was worth it. Our windows are lovely! The installers were courteous and professional. They completely cleaned up and hauled away the old windows. We recommend RbA wholeheartedly."

Anita King
Aug 26, 2022

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