Low-E (low-emissivity) glass is coated with a low-emittance material designed to reflect heat. A window made with Low-E glass repels ultraviolet rays that generate heat during the summer but absorbs UV rays and lets heat in during winter. The better insulated the window glass, the more comfortable your room temperature. Low-E 180 With a glass U-Factor of just 0.26 and an SHGC of 0.69, Low-E 180 Glass is an excellent basic product for passive solar applications. By blocking heat loss to the outside of the glass, the high solar gain glass keeps homes warm in winter and cool in summer. Low-E 272  Low-E 272 Glass delivers year-round comfort, reflecting an intermediate level of heat back into the room in winter and rejecting the sun’s heat and uv rays in summer. This product’s patented coating provides clarity and high-performance low-solar control, reducing window heat gain by 50% compared to ordinary glass.…