The Basics

25 cheap ways to keep your house cooler

Simple
changes such as moving lamps away from thermostats can save you
hundreds of dollars. Here are more money -- and energy -- saving tips.

Get the most from your air conditioning

• Open
  windows and use portable or ceiling fans instead of operating your air
  conditioner. Even mild air movement of 1 mph can make you feel three or
  four degrees cooler. Make sure your ceiling fan is turned for summer --
  you should feel the air blown downward. If you live in a relatively dry
  climate, a bowl or tray of ice in front of a box fan can cool you as it
  evaporates.

• Use a fan with your window air conditioner to spread the cool air through your home.

• Without blocking air flow, shade your outside compressor. Change air filters monthly during the summer.

• Use a programmable thermostat with your air conditioner to adjust the setting at night or when no one is home.

• Don't
  place lamps or TVs near your air conditioning thermostat. The heat from
  these appliances will cause the air conditioner to run longer.

• Consider
  installing a whole house fan or evaporative cooler (a "swamp cooler")
  if appropriate for your climate. Attics trap fierce amounts of heat; a
  well-placed and -sized whole-house fan pulls air through open windows
  on the bottom floors and exhausts it through the roof, lowering the
  inside temperature and reducing energy use by as much as third compared
  with an air conditioner. Cost is between $200 and $400 if you install
  it yourself. An evaporative cooler pulls air over pads soaked in cold
  water and uses a quarter the energy of refrigerated air, but they're
  useful only in low-humidity areas. Cost is $200 to $600.

• Install
  white window shades, drapes, or blinds to reflect heat away from the
  house. Close curtains on south- and west-facing windows during the day.

• Install
  awnings on south-facing windows. Because of the angle of the sun,
  trees, a trellis, or a fence will best shade west-facing windows. Apply
  sun-control or other reflective films on south-facing windows.

Landscaping for a cooler house

• Plant
  trees or shrubs to shade air conditioning units, but not block the
  airflow. A unit operating in the shade uses less electricity.

• Grown on trellises, vines such as ivy or grapevines can shade windows or the whole side of a house.

• Avoid
  landscaping with lots of unshaded rock, cement, or asphalt on the south
  or west sides. It increases the temperature around the house and
  radiates heat to the house after the sun has set.

• Deciduous
  trees planted on the south and west sides will keep your house cool in
  the summer. Just three trees, properly placed around a house, can save
  a few hundred dollars in annual cooling and heating costs. In summer,
  daytime air temperatures can be 3 degrees to 6 degrees cooler in
  tree-shaded neighborhoods.

Little things mean a lot

• Replace incandescent bulbs with compact fluorescents; they produce the same light but use a fifth the energy and heat

• Air-dry dishes instead of using your dishwasher's drying cycle.

• Use a microwave oven instead of a conventional electric range or oven.

• Turn off your computer and monitor when not in use.

• Plug home electronics, such as TVs and VCRs, into power strips and turn power strips off when equipment is not in use.

• Lower the thermostat on your hot water heater; 115° is comfortable for most uses.

• Take showers instead of baths to reduce hot water use.

• Wash only full loads of dishes and clothes.

Don't air-condition the whole neighborhood

• Caulking and weatherstripping will keep cool air in during the summer.

• If you see holes or separated joints in your ducts, hire a professional to repair them.

• Add
  insulation around air conditioning ducts when they are located in
  unconditioned spaces such as attics, crawl spaces, and garages; do the
  same for whole-house fans where they open to the exterior or to the
  attic.

• Check to see that your fireplace damper is tightly closed.

Plan ahead

More costly but effective cooling measures are available as your home undergoes normal upgrades and repairs.

• A
  10-year-old air conditioner, for example, is only half as efficient as
  a new one. A quick check of your air conditioner's efficiency can help
  you decide whether to call in a service professional. Use a household
  thermometer to measure the temperature of the discharge air from the
  register and the temperature of the return air at the return-air grill.
  (Keep the thermometer in place for five minutes to get a steady
  temperature.) The difference should be from 14 to 20 degrees, experts
  say. An air conditioner that's not cooling to those levels could be low
  on refrigerant or have leaks. A unit cooling more than 20 degrees could
  have a severe blockage.

• Using
  light shingles on a new roof can cut the amount of heat the house
  absorbs. Repainting in a light color, especially south- and west-facing
  exterior areas, helps as well.

• Upgraded
  insulation in the attic and double-paned windows all around, complete
  with tinting to reflect sunlight, are good ideas, too.