An air conditioner, whether a window unit or a central air conditioning system, keeps your house cool when the weather outside is toasty warm or frightfully hot. To set the vents to maximize air conditioner cooling is easy; just open the louvers all the way and direct them toward the center of the room. However, there's more to air conditioning than setting the temperature low and opening louvers on floor, wall or ceiling vents. Increasing air circulation through the room and/or house also plays a role in maximizing the cooling effects of your air conditioner.
Open the vent louvers and direct the airflow toward the center of the room to maximize the cooling effect.
Window Air Conditioner
A window air conditioner generally has louvers on the front to direct the airflow into the room. Pivot the louvers from side to side and/or up and down to maximize airflow to the center of the room. If the louvers are not adjustable or point in the wrong direction for your needs, add-on deflectors can help redirect the airflow.
Window units may also have a fresh air vent control that allows you to close the vent and recirculate the indoor air or open the vent to draw in fresh air, while a third option opens both the vent and exhaust to allow indoor and outdoor air exchange. In general, unless you need to vent odors or smoke outside, it's best to keep the fresh air vent closed and recirculate the already-cooled air.
Central Air Conditioner
To maximize cooling, don't close the vents in unused rooms. Central air conditioning is predicated on the air circulation through the entire house. Closing vents can make "hot spots" within the home and can reduce the effectiveness of the air conditioning unit. In addition, closing vents can affect the efficiency of the ducting system and can push cool air out of leaky ducts into the attic or crawl space.
Adjust the louvers of the vents if they are directed toward a wall or corner. If they are not adjustable or are frozen in place, consider changing the vent so you can redirect the airflow. Alternatively, you can add a deflector to direct the cool air to the center of the room.
More Ways to Maximize Cooling
When installing a window unit or a new central heating, ventilation and air conditioning (HVAC) system, position the air conditioner where it is at least partially shaded to maximize efficiency. An awning, hedge or shade tree that shades the unit can reduce the strain on the equipment as it cools your home. Make sure that there is a minimum of 12 to 24 inches of clearance around the unit, including above it, per the manufacturer's instructions.
Clean the vent louvers, change the filters and vacuum or rinse the condenser coils regularly to remove dirt and debris that block the airflow through the unit. Unplug window units and then wipe interior vents and spray exterior coils gently with a mixture of a mild dishwashing liquid and water. Remove grass, weeds and plant debris from around exterior HVAC units and then rinse with a garden hose nozzle. Don't use a pressure washer, as it can damage the coil fins.
Add floor or ceiling fans to increase air circulation in rooms. In addition, rearrange furniture to avoid blocking vents and maximize the cooling effect in your favorite sitting place. Install insulated curtains or window films to block sunlight from the room and keep it cooler.
- Home Depot: SPT User's Manual: Window Air Conditioners
- Willard Heating and Air Conditioning: Maximize Vent Positioning for Optimal Air Flow
- Fountain Hills Air Conditioning & Heating: Why Airflow Can Make or Break Your Air Conditioner’s Performance
- Deljo Heating & Cooling: How Much Clearance to Have Around Your Air Conditioner
- Carrier: Air Conditioner Coil Cleaning
Ruth de Jauregui is the author of 50 Fabulous Tomatoes for Your Garden. She writes numerous home and garden articles for a variety of online publications. She got her start as a book and cover designer in San Francisco for William (Bill) Yenne at American Graphic Systems. In addition to designing books, she wrote her first book, Ghost Towns. With several nonfiction books under her belt, de Jauregui recently published her first novel, Bitter.