Controls Sunlight to Create a Comfortable Living Environment and Reduce Air Conditioner Burden The Solar Reflective Glass Block features a metal oxide coating on the inside surface which greatly reflects solar energy while reducing the passage of sunlight. Additionally, the air pressure inside the glass block is one-third the atmospheric pressure. These features help to keep down the use of air conditioning, thus contributing to energy conservation. And because the reflective coating is inside the glass block, it will not deteriorate by exposure to air or cleaning detergents. When used in regions with a hot climate or for walls that receive strong direct sunlight, Solar Reflective Glass Blocks will control the sun's effects to help create a more comfortable living environment.