Here are some basic rules to follow for keeping your cooling bill down:
Caulk, weather-strip, and insulate (especially the attic) to close air gaps.
Plan hot work (washing and drying clothes, baking, cooking) for coolermorning and evening hours.
Pull drapes and shades over windows facing the sun. Keep windows and doors closed when the air conditioning is on.
Use a thermostat control to automatically increase or decrease hometemperatures for daytime/nighttime differences to save money.
Set thermostat control at highest comfortable level-- each degree raised reduces energy consumption by 3-4 percent.
Clean or replace air filters regularly.
With a new system, consider a service contract for a specified period of time.
Keep the outside unit free of leaves or other airflow obstructions.