Weather Stripping: Not Just for Winter
Before you add to your electric bill trying to keep cool this summer, add something to your windows instead. The first principle of passive cooling is to keep the heat from getting inside. Even though it seems like a wintertime activity, weather stripping your windows and doors and caulking gaps can really make a difference in summer, too.
There are lots of ways to shade your windows from the sun, and if they seem a little old-fashioned, it's because they worked even before there was air conditioning. Large roof overhangs and porches, awnings, shutters and louvers can all be seen on old southern homes.
Awnings can actually reduce summer heat gain by up to three-quarters. And you can remove them in winter to let the sunlight in when you need it. Light-colored awnings are best because they deflect more heat. Solar screens are another option. Installed outdoors, they can cut heat gain in half, and you can still enjoy the view.
Interior Window Treatments
Interior window treatments aren't quite as effective as the outdoor methods, but they're better than nothing. Densely woven fabric drapes, Venetian blinds or roller shades will control some heat gain just by keeping out direct sunlight. Again, lighter colors are most effective.
If you're replacing your windows, ask about low-E glass. A low-E, or low-emissivity coating, depending on which surface of the window it's applied to, can keep heat where you want it and keep your costs down year-round.