Sliding patio doors are probably the most popular for their affordability and easy use. By merely sliding open the large glass window, you can let in the fresh air and provide an easy entry for special occasions outside. A swinging door would be a nuisance during these situations. While the door is closed, a glass sliding door acts as a window and can let in an abundance of natural light into the home, making a room inviting and making it look much bigger. Sliding patio doors are generally made with glass, and some are made with a Low-E glass that is energy efficient. Low-E glass has a special coating that blocks UV rays (similar to sunglasses) to protect carpet and furniture fading from sunlight. The UV ray protection will still allow sunlight to enter the room while keeping the room cool. Therefore, there is no need to turn on the AC so high during the hotter months.