What is ENERGY STAR?

ENERGY STAR is a program designed to promote greenhouse gas reductions through improving energy efficiency in products, homes and businesses. A joint program of the U.S. Environmental Protection Agency (EPA) and the U.S. Department of Energy(DoE), ENERGY STAR aims to help consumers save money and protect the environment by promoting energy efficient products and practices.

The ENERGY STAR requirements for products to earn the label center on the ability to improve energy efficiency nationwide, deliver comparable performance and allow consumers to recoup a price premium through savings on utility bills. The ENERGY STAR requirements for residential windows and doors establish the parameters for U-factor (the inverse of R-Value) and Solar Heat Gain Coefficient (SHGC). The requirements for different climate zones are illustrated in the graphic below.

ENERGY STAR breaks down the performance requirements by climate zones because different regions experience different weather and temperature conditions and therefore benefit from different performance characteristics. In a heating dominated climate, like the Northern region of the U.S., generally the most important performance characteristic is a window’s ability to prevent unwanted heat loss during the cold winter months. For that reason, in the Northern Climate Zone ENERGY STAR requires a low U-factor, while SHGC is more flexible. In warmer, cooling dominated climates, the principal concern is typically preventing unwanted heat gain during hot summers. Thus in the Southern Climate Zone, a low SHGC is paramount whereas the U-factor requirements are less stringent.

The Benefits of ENERGY STAR Windows

Replacing existing windows with ENERGY STAR qualified windows delivers the following benefits:

• Saves money: ENERGY STAR windows improve the efficiency of your home, lowering your energy consumption and saving you money on your utility bills.

• Improves Comfort: with ENERGY STAR windows, you can minimize cold drafts in the winter and overheating in the summer, keeping your house a more comfortable temperature all year round.

• Protects against UV rays: the low-E coatings on ENERGY STAR windows block large percentages of UV rays and prevent your furniture from fading.

 The Serious Difference: Advantages of SeriousWindows

SeriousWindows vinyl and fiberglass residential windows with low SHGC glass packages meet the minimum performance requirements of ENERGY STAR in all climate zones. Powered by SeriousGlass, SeriousWindows’ unmatched combination of high performance characteristics deliver optimal overall results: high thermal performance, optimal solar control tailored and high visible light transmittance.

• High Full Frame R-values for Super-Insulating Performance: Vinyl windows offer full-frame R-values of up to 6.67 (U-factor of 0.15), and fiberglass SeriousWindows reach full-frame R-values up to 11.1 (U-factor 0.09). High R-value means excellent insulation, which is the single most important characteristic of an energy efficient window.

• Tune Your Home for Energy Savings & Comfort: SeriousGlass packages offer a broad range of SHGC values, which allows you to “tune” your home based on its unique orientation to the sun. With customized low-E coatings on the glass and suspended film, your SeriousWindows allow exactly the right about of solar heat into your home.

• Comfort: SeriousWindows block 99.5% of harmful UV rays, offer 40% more solar damage resistance, and maintain an ideal average interior glass temperature between 60 and 70 degrees. Warmer glass temperatures not only make windows more comfortable to live near, but also reduce cold air circulation caused by cold glass temperatures. SeriousWindows also significantly reduce the risk of window condensation by keeping the glass temperature close to room temperature.

• The Anti-Triple Pane Window: SeriousWindows employ suspended film technology, which improves insulation and achieves higher performance across a broad spectrum of glazing characteristics without any of the design and durability limitations typical of triple-pane glass systems.

What to look for

As the ENERGY STAR label indicates, two of the most important numbers to look at when choosing the perfect windows for your home are U-factor (R-value) and SHGC. When shopping for windows, these values are readily available on the NFRC or ENERGY STAR label. The table below shows how two of the most popular high performance SeriousWindows fiberglass series compare to ENERGY STAR and other major brands on these two points. SeriousWindows deliver higher R-values and a full range of SHGC for optimal, regionally-tuned solar control:

Learn more

View performance data for all SeriousWindows here. To learn more about the ENERGY STAR program visit the ENERGY STAR website. ENERGY STAR not only qualifies products based on their energy performance, but also offers whole building certifications for new construction homes and commercial buildings.

SeriousWindows offers a full range of low to high SHGC options to allow for custom tuning of every home based on its climate zone and orientation. When working with certain energy design standards and programs, including Passive House and Net Zero Energy Homes, selective use of high SHGC glass packages delivers optimal solar results.