What is Low-Emittance or “Low-E” window glass?
A low-emittance (or “Low-E”) glass coating is a microscopically thin film applied to the glass. This coating keeps heat inside in winter and outside in summer. Choose a Low-E coating based on your climate. • High Solar Gain Low-E – These coatings allow as much heat from the sun to enter the house as clear glass. High solar gain coatings offer the greatest energy savings in regions with cool summers and very cold winters. Windows with high solar gain Low-E coatings generally have Solar Heat Gain Coefficients between 0.56 and 0.75. • Moderate Solar Gain Low-E – These coatings screen a portion of the sun’s heat, keeping the home cooler in summer but admitting a good amount of solar heat in winter. Moderate solar gain Low-E coatings offer the greatest energy savings in regions with moderately hot summers and cold winters. Windows with moderate solar gain Low-E generally have Solar Heat Gain Coefficients between 0.41 and 0.55. • Low Solar Gain Low-E – These coatings screen the most heat fro
