You may have heard it described as the NFRC label. NFRC stands for National Fenestration Rating Council® . This independent, nonprofit organization rates and certifies windows and doors according to strict requirements.
The NFRC doesn’t recommend which windows to buy. Instead, it helps you do an apples-to-apples comparison of different brands and styles.
At first glance, though, the NFRC label can be a bit intimidating. We’ll help you decode it.
The NFRC’s ratings measure: U-Factor. This tells you how well the window insulates. The lower the U-Factor, the more energy efficient the window. Solar heat gain coefficient. This measures how effective the window is at blocking the sun’s radiant heat. The lower the solar heat gain coefficient, the less solar heat the window allows into your home. Visible transmittance. This quantifies how much light the windows allow into your home. Windows use various degrees of tinting to control energy efficiency and solar heat gain. The lower this number, the more tinting you’ll notice.