National Fenestration Rating Council (NFRC) certified products are independently tested, certified, and labeled to help you make the best purchase decision for your needs. While the ENERGY STAR label tells you if a product is energy-efficient, the NFRC label helps you compare between energy-efficient products by breaking down a product’s energy performance.
The NFRC label helps you compare between energy-efficient windows, doors, and skylights by providing you with energy performance ratings in multiple categories.
U-Factor measures how well a product can keep heat from escaping from the inside of a room. The lower the number, the better a product is at keeping heat in.
Range: 0.20–1.20
Look for: Low numbers
Solar Heat Gain Coefficient measures how well a product can resist unwanted heat gain, which is especially important during summer cooling season. The lower the number, the less you’ll spend on cooling.
Range: 0–1
Look for: Low numbers
Visible Transmittance measures how well a product is designed to effectively light your home with daylight, potentially saving you money on artificial lighting. The higher the number, the more natural light is let in.
Range: 0–1
Look for: High numbers
Air Leakage measures how much air will enter a room through a product. The lower the number, the fewer drafts you’ll experience.
Range: 0.1-0.3
Look for: Low numbers
