Low-Emissivity Glass is a highly reflective glass which emits very low levels of radiant thermal and heat energy. It is also known as thermal insulating glass. During glass manufacture low-e coatings are used so that a very minimum amount of ultraviolet and infra-red light can pass through the glass without compromising on the natural light penetration into the interiors. In this product glass is coated with an ultrathin layer of metal and the coating is applied to the inner surface of the glass. The metallic coating acts as a reflector of heat.