Install ceiling fans or use the fans you already have
Set on counterclockwise in the summer months ceiling fans create a wind chill effect that will make you feel cooler without having to lower the temperature setting on your thermostat. Operating the fans counterclockwise draws the cooler air upwards.
Maintain your air conditioning system
Even if you have cold air blowing out of your vents it doesn’t mean your air conditioning system doesn’t need maintenance. This maintenance includes simple things like replacing the air filter, cleaning the condenser coils on the exterior unit (clogged coils will reduce airflow and force the system to work harder), inspect the condenser unit fan, inspect wiring, etc. All this work can be done by an HVAC contractor at a reasonable cost.
Keep your windows covered
When direct sunlight shines into your home through the windows it heats the interior of your home causing your air conditioner to work harder to cool the house. By closing your blinds or curtains on windows that receive direct sunlight your air conditioner won’t have to work as hard to cool the space.
Limit oven use
During particularly hot days consider cooking on a grill outside. The use of your oven, especially if you’re not cooking low and slow, can really heat up your kitchen and cause your air conditioner to work even harder to keep the house cool.
Keep interior doors open
This simple act is vital in keeping your home cool as it allows air to circulate freely keeping hot spots to a minimum thereby regulating the temperature within your home.
Install heat reducing film
Did you know that on average 30% of all energy used to heat and cool homes escapes through your windows? 3M and other similar manufactures make some interesting Low-E window films that they claim block up to 78% of the sun's heat without blocking natural light and your view.