● Use an ENERGY  STAR programmable thermostat with your air conditioner to automatically increase the setting at night or when no one is home.
● When you come home and the house is hot, do not turn the thermostat below what is comfortable (train yourself to enjoy 80º or even more).  Turning the thermostat lower will NOT reduce the time to cool the house, but will cost you a lot of money, especially if you forget to move it back to 80º
● 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 an attic fan.
● Add insulation in the floor of your attic, and house walls if possible, the thicker the better to keep your house comfortable.
● Install white window shades, drapes, or blinds to reflect heat away from the house.
● Install awnings on south-facing windows. Because of the lower angle of the sun, some trees, a trellis, or a fence can help shade west-facing windows.
● Apply sun-control or other reflective films on south-facing windows.
● Check your air conditioner's efficiency. Use a household thermometer to measure the temperature of the cool air coming out 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. Less than 14º could mean low refrigerant or leaks. A unit cooling more than 20 degrees could have a severe blockage.
● Use a whole-house or attic fan, especially if you live in a multi-story home where the upper floor stays uncomfortably warm. Attics trap fierce amounts of heat and can rise to 150º.  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.  (Or you can just put a small, less expensive fan in one end of the attic to pull air in the other end during the heat of the day.)
● When buying new heating and cooling equipment like a central a/c unit, proper sizing and quality installation are critical to your home's energy efficiency and comfort. Remember: Bigger doesn't always mean better. If the air conditioner is too large for your home, you will not only increase your energy costs, you'll be less comfortable in your home.
● The outdoor porch or post lamp is one of the highest used light fixtures in a home, and is the perfect place to install ENERGY STAR qualified lighting products. Many compact fluorescent lamps (CFLs) will fit easily into existing porch lights. Or install a new ENERGY STAR qualified outdoor fixture that saves energy through advanced CFL technology, a motion sensor and/or a photocell that turns the light on only when someone is present or on at night and off in the morning.
● Replacing single-paned windows with ENERGY STAR qualified windows or choosing ENERGY STAR over the typical clear-glass double-paned alternative can save a significant amount of money on your energy bill._ ENERGY STAR qualified windows, doors, and skylights keep your home cooler in the summer and warmer in the winter, making you more comfortable. Many ENERGY STAR qualified windows, doors, and skylights act like sunscreen for your house, protecting your photographs, artwork, furniture, carpets, and wood floors from sun damage.  See below for info on the new TAX CREDIT for installing ENERGY STAR qualified home improvements.

Landscape for a Cooler House
● Plant trees or shrubs to shade air conditioning units, but not block the airflow. An AC 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 because 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 between $100 and $250 annually in cooling and heating costs. Daytime air temperatures can be 3 degrees to 6 degrees cooler in tree-shaded neighborhoods.

Reduce the Heat You Create
● Replace all incandescent bulbs with compact fluorescents.
● Plug home electronics, such as TVs, VCRs, computers, printers, cell phone chargers, etc. into power strips and ALWAYS turn power strips OFF when equipment is not in use.  (Remember, if any AC adapter is plugged in, it is ALWAYS drawing power, heating your house and costing you money. In the average home, 40% of all electricity used to power home electronics is consumed while the products are turned off.)
● Air-dry dishes instead of using your dishwasher's drying heat cycle.
● Don't use your oven, use your stovetop, or grill outside.
● Turn off your computer and monitor when not in use.
● Dry clothes on a clothesline, not in a dryer, whenever possible.
● 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 Entire Neighborhood
● Caulking and weather-stripping will keep cool air in during the summer.  See the ENERGY STAR website for excellent brochures on how to find and patch the leaks.
● 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. Use duct insulation material rated at least R-6.
● Check to see that your fireplace damper is tightly closed (if there is any remaining air flow, put an air block in whenever it is not in use, or install tight glass doors across the entire front).
● Use the Home Energy Yardstick to compare with averages.  The typical household spends $1,900 a year on energy bills. With ENERGY STAR, you can save up to 30% or more than $600 per year.

Take Advantage of Tax Credits
The Energy Policy Act of 2005 allows consumers to receive a federal TAX CREDIT up to $500 for making energy efficient improvements on their home, including installing ENERGY STAR qualified windows, skylights, new heating and cooling systems, and more.  In addition, TAX CREDITS up to $2,000 are available for solar hot water heating, photovoltaics, or fuel cells.  Click here for complete details.  (Remember that a tax credit is money directly in your pocket; it is much better than a tax deduction.)

Thanks to the Department of Energy's Energy Star program which provides most of these tips.