How do I make sense of an NFRC label on EcoShield vinyl windows?
NFRC stands for National Fenestration Rating Council. The NFRC is an independent non profit organization which tests and certifies windows to certain performance ratings to help consumers compare the performance of one window with the performance of another window. The windows are tested using computer simulation and physical testing at laboratories accredited by the NFRC. The NFRC label provides the results of this testing using various standard ratings. On EcoShield vinyl replacement windows and new construction windows the NFRC label contains the U-Factor, Solar Heat Gain Coefficient, Visible Transmittance, and DP Factor. The U-Factor measures the rate at which heat transfers and is an indicator of how well a window insulates so the lower the U-Factor the better the window insulates. According to Energy Star U-factor values generally range from 0.25 to 1.25. The Solar Heat Gain Coefficient (SHGC) measures the solar energy that is transmitted through the window. This measurement is s
