Radiant or solar heat gained through windows and glass doors can increase your air conditioning costs and reduce occupant comfort. The more glass your home has, especially on east, west, and south exposures, the more important it is to have some type of window shading to improve comfort and reduce air conditioning bills.

The most effective way to reduce excess solar gain is with exterior shading. Whenever possible, try to block the sun from shining directly on windows or glass doors. Exterior shading can block up to 95% of the sun's heat. Horizontal overhangs, awnings, tinted and reflective films, and louvers are commonly used for exterior shading. Some window films also make the glass more difficult to break, thus making them an ideal choice for security reasons as well.

Landscaping is also an effective means of shading windows and glass doors. Shade trees on east and west exposures can reduce cooling costs and prevent rooms on those sides of the home from overheating.

Unfortunately, exterior shading is not always a practical option. If not, some type of interior shading should be considered.

There are many choices of shading materials and placement. Interior shading devices include venetian blinds, shades, and draperies. These devices can block up to 65% of the sun's heat that would be transferred through the window. Interior shading can improve the aesthetics of the room as well as the comfort. Insulated drapes or shades can be used to reduce heating loss in the winter and heat gain in the summer.

Any shading device that can be removed during non-air conditioning months is desirable over a permanent device, particularly on southern exposures. South facing windows can be a good source of "free" heating in winter. The type of shading that will work best depends on your specific situation and needs.