While using air conditioning can sometimes seem unavoidable, there are ways to design homes that don't need air conditioning at all. It's easy to forget, but many homes didn't have this amenity even as recent as 10 years ago, and most often naturally cooled environments actually feel better than artificially cooled air. Find out ways to inexpensively and easily incorporate naturally cooling into your home, after the jump.
The following building techniques can used individually, but most of them benefit from and compliment one another:
Cross-Ventilation: This strategy is something just about any dweller can implement, though it's best when purposefully designed into a building. By opening windows on opposite sides of the room or even on different floors of the house, cool, fresh air is encouraged to enter the house and flow through and then flush out of opposing openings.
Transoms: Installing these mini windows above doors is one of the oldest tricks in the book. Operable transoms allow natural light and vent to flow from bedrooms to areas that typically don't have access to natural light and vent, such as hallways, closets and other rooms without windows. Transoms also provide this benefit of exhausting hot rising air while allowing doors to stay closed for privacy and sound control.
Whole House Fans: Using a whole house fan is one of the easiest and least expensive ways to flush your house of hot and stale air. Whole house fans are typically installed in the floor of the attic (or the ceiling of the highest area of the house) near the stairway or another opening that spans the height of the house. Whole house fans are not as loud as they used to be and only need to be run for a couple of minutes to flush the house: open a few windows and doors, flip on the fan and just a few minutes later your home will feel fresh and cool. Whole house fans are especially effective during early fall and late spring when the outside air is nearly at the perfect temperature but it's not hot enough to use the air conditioning.
Ceiling Fans: Any high-use room such as bedrooms and family rooms should have a ceiling fan. It's an easy way to circulate indoor air and cool any bodies nearby, however it's unnecessary to run these if no one is around. Ceiling fans are inexpensive to install, are easy to retrofit and can be the light source for a room.
Overhangs: South facing windows should be shaded from the summer sun to keep indoor temperatures cool. When designed correctly the overhangs will allow full winter sun to enter the house and completely shade the windows from the hot summer heat — the size and design of the overhang will depend on your climate, but shading devices can include trellises, shutters, roof overhangs and shelves. It can also be as simple and straightforward as planting trees in key locations and using window shades.
High-Albedo Roofs & Paving Surfaces: Using light colored and highly reflective surfaces helps keep buildings and adjacent ambient temperatures. Look for roofing and paving with high SRI (solar reflectance index) values, which will be better at reflecting both light and heat to keep your building cool.
All in all, the climate of your home should be taken into account when considering cooling techniques, because not all of the above cooling strategies will be equally affective. When used in conjunction with proper insulation and air sealing, it's possible to keep your home cool without air conditioning at all.
(Images: Good Question: Transom Window or Screen?, Cool Roof Shingles by GAF, Best Ceiling Fans 2010, Green Tour: A Barn Inspired Wisconsin Retreat)