The Solar Heat Gain Coefficient or (SHGC) measures how well a product blocks radiant heat gain and is listed on the NFRC label. Technically it is “the fraction of incidental solar radiation admitted through a window (both directly transmitted and absorbed) and subsequently released inward” which is expressed as a number between 0 and 1. The lower the number is, the less heat is transmitted into the building which is good thing in hot climates. For More
