What Is The Solar Heat Gain Coefficient (SHGC)?
The SHGC for windows (expressed as SHGCw) measures how readily heat from direct sunlight flows through a window system. The SHGC is the fraction of incident solar radiation admitted through a window, directly transmitted as well as absorbed and subsequently released inward. SHGC is expressed as a number between 0 and 1. The lower a window’s SHGC, the less solar heat it transmits.
Information on SHGC, u-Factor, and Visible Light Transmission.