Without energy-efficient window treatments, as much as 50% of a home's heating and cooling energy can be lost through its windows. All Hunter Douglas window fashions provide window insulation, offering your home increased protection against heat loss during the winter, as well as minimizing the sun's heat or "solar heat" during the summer. Solar Heat Control The warmth provided by the sun, its solar energy, may be desirable during the winter to help heat your home, yet it can make a room overly hot and uncomfortable while driving up air conditioning costs in the summer. Many Hunter Douglas products are designed to reduce the amount of solar heat that passes through the window, which is known as the Solar Heat Gain Coefficient (SHGC). The lower the SHGC, the more protected your home is from the sun's heat. To enjoy the sun's warmth when desired, simply raise or open the window fashion and invite it in.