Drapes, shades and external panels all help to preserve energy in the home. Typically, the thicker the covering, the less heat is transmitted through the glass of the door.
Exterior coverings prevent heat from traveling through the glass from outside during warm months. Common exterior coverings include reflective rolling shades and solar screens. Rolling shades can block the heat from hitting the glass, reducing heat transmission into the home. Because they roll into place, they can be retracted when desired, allowing the home owner to enjoy the sunlight. Solar screens operate by absorbing the sunlight that would otherwise hit the glass causing heat exchange. Exterior insulating films are also available. These films can be clear or decorative, and the effectiveness is generally high, depending on the rating of the chosen film.
Interior coverage options are also available for patio doors, such as drapes or blinds. Interior coverings are usually most effective during cold months, as they are designed primarily to block heat from escaping the home. Drapes are the least effective solution available for an interior covering, but can still provide some energy loss from occurring. The thicker the drapes, the better the blockage, especially if they are designed to overlap the glass doors. Plantation doors and sliding panels are more effective at keeping heat from escaping, though panels are best, as the overlapping edges lower the chances of leakage.