Sure, air conditioning feels good on a hot summer day - until you look at your electricity bill. If you don't have AC, just want to save some money, or want to do things that are more sustainable, you can keep your house cooler with these easy, old-fashioned tips for using your windows to good advantage.
We know that hot air rises. You can help outdoor breezes cool your house more efficiently by opening lower-level windows on the windy side of the house and upper-level windows on the downwind side. This works even better if you have double-hung windows. Just open the lower sections on the windy side of the house and the upper sections on the downwind side. This creates air movement through the house to exhaust hot air out. Making the upper openings larger than the lower openings increases the effect.
Even if there isn't much breeze blowing outside, you can simulate air movement through the house by using fans placed in the right windows. Fans are a lot cheaper to run than air conditioning. Position fans in upper-level windows to blow out air. An attic fan will work the same way by pulling cool air up through the house and exhausting hot air. This kind of window engineering works even without fans. Hot air still has to rise, and it will escape through your upstairs windows while cool air is drawn in downstairs to replace it.
Naturally, the tips above work most effectively at night, when outside temperatures are cooler. If you draw in the cooler air at night, then maintain that temperature during the day, your house can keep nice and comfortable before you need to switch on the AC.
During the day, the sun shining through your windows heats the air inside the house, but installing awnings will reduce the effect. According to the U.S. Department of Energy, window awnings can cut solar heat gain in the summer by up to 65% on south-facing windows and 77% on west-facing windows. Retractable awnings allow you to take advantage of their shade in the summer but enjoy the warming sun in the winter.