Like regular insect screening, sunscreens let breezes in and keep insects out. Mounted in wood or aluminum frames, sunscreens should be installed on the outside of the windows, and, for maximum benefit, should cover the whole window. By stopping most of the heat before it reaches the windows, interior heat is diminished, thereby substantially reducing the amount of air conditioning needed.
Most people living in the South spend more money for cooling than they do for heating.
Based on a 165-day cooling season, sunscreens placed over east and west windows save about one dollar for every square foot of glass covered during the cooling season. Reduced fading of curtains and furniture. Works with windows opened or closed. The open mesh allows cool breezes to flow through, yet keeps insects out. Works in winter, too.