Both exterior and interior shades control heat gain. Exterior shades are generally more effective than interior shades because the sun is blocked before it enters the home. When deciding the shade devices to use and where to use them, consider whether you are willing to open and close them daily or just put them up for the hottest season. You will also want to know how they will affect ventilation. Exterior shading devices include awnings, louvers, shutters, rolling shutters and shades, and solar screens.
Awnings are very effective because they block direct sunlight.
They are usually made of fabric or metal and are attached above the window and extend down and out. A properly installed awning can reduce heat gain up to 65 percent on southern windows and 77 percent on eastern windows. A light-colored awning does double duty by also reflecting sunlight. Maintaining a gap between the top of the awning and the side of your house helps vent accumulated heat from under a solid-surface awning. An east or west window needs a drop of 65 percent to 75 percent of the window height.