The dog days of summer can really put the heat on electricity bills and put even the best air conditioning systems to the test.

Here are six tips to keep your utility bills down this summer:

1. An air conditioner set at 70 degrees can cost twice as much to operate as one set at 78 degrees. Raise the thermostat by 2 degrees above its normal setting. You'll still be comfortable, and your pocketbook will thank you.

2. Set the thermostat to 80 degrees when you'll be out of the house for several hours and lower it when you return. But don't shut the air conditioner off; it's less efficient to cool the house back down than to leave it set at a higher temperature.

3. A ceiling fan uses about as much energy as a 100-watt bulb, but it can make a room feel up to eight degrees cooler. In summer, blades should turn counterclockwise, pushing air downward to create a cool breeze.

4.  Keeping windows closed and curtains drawn during the day can reduce cooling costs by 30%.

5. Lights, computers, and televisions all generate heat. Turn them off when they're not in use.

6. Get your air conditioner serviced before you need to turn it on to avoid the rush in service calls made to air-conditioning repair companies on the first hot day of the year.

7. Create shade for the outdoor part of your AC unit, but keep the area around the exterior unit clear of leaves, bushes, and other obstructions to ensure adequate airflow.

8. Clean or replace the air filter monthly. Clogged, dirty filters block air flow and make a unit work much harder. A clean filter can save up to 10% on your bill.