ENERGY STAR® and NFRC Labels: What’s the Difference?

If you’ve been shopping around for new entry doors or windows, you may have noticed the ratings and certification labels affixed to every unit. In today’s post, Timberland Exteriors explains how these labels work, and how they can help you get the best replacement windows for your home.

• U-Factor. The U-Factor measures how well the product can keep heat from escaping. The lower the number, the better its insulating capabilities. In some products, R-Value is used instead. Since it measures thermal resistance, the R-Value will be inversely proportional to the U-Factor. That is, a product with a low U-Factor rating will have a correspondingly high R-Value.

• Solar Heat Gain Coefficient. SHGC measures how well a product can resist unwanted heat gain from the sun — lower numbers mean lower heat gain. Homeowners in constantly cold locales may benefit from windows with high SHGC values, as it can help reduce their heating costs.

• Visible Transmittance. VT measures how well a product allows natural light. Tinted windows typically have lower VT ratings, with clear glass being the opposite.

• Air Leakage. This measures how much air will enter a room through the product. Lower numbers mean fewer drafts.

ENERGY STAR® Labels

You’ve probably seen ENERGY STAR labels on a wider selection of products, from washing machines to computers — virtually any product that uses energy. ENERGY STAR labels provide an even simpler way for consumers to choose the most energy-efficient product. In terms of fenestrations, ENERGY STAR relies on the NFRC ratings to determine whether or not a window, door or skylight can be considered as energy efficient.

ENERGY STAR labels simplify things for homeowners at point of purchase. For example, if you are simply looking for energy-efficient fenestrations but are not looking for specific features (like SHGC or VT), then all you need to do is pick the products that have the ENERGY STAR label. However, if you are looking for a window that will allow natural light but you’re worried that the sunlight might heat up the room, the solution is to choose windows with low SHGC and high VT ratings.

Your window contractors at Timberland Exteriors can help you learn more about choosing the right windows for your home. Give us a call at 651-439-1760, or fill out our contact form to schedule a free, no-obligation estimate. We serve Maplewood, MN, and the surrounding communities.