For enhanced energy performance, Low Emissivity (Low E) glass is extremely important. Low E is thin, transparent layers of metal oxide applied to the glass surface. In warmer temperatures, Low E helps filter unwanted heat and ultraviolet rays from the sun from entering your home, thereby keeping your home cooler. In colder temperatures, the Low E coating allows heat rays from the sun to pass through, helping to warm interior temperatures. This means that regardless of the outside temperature, climate or season, Low E glass helps reduce the costs needed to heat or cool your home by using the rays from the sun to your advantage.