By Tom Feiza, “Mr. Fix-It”                           

Central air conditioning is a pleasure – unless it breaks down or you get that really high electric bill. But proper care and feeding of your air conditioner will avoid headaches and help you get the most bang for your buck, energy-wise.

The Inside Story

Start indoors by checking the filter of the fan/coil unit. You’ll find this filter in the return duct for a basement AC unit, in a hallway for an attic unit, or in a closet next to a closet unit. Check the filter once a month and either change or replace it – depending on your unit’s requirements – when dirty. A dirty filter blocks normal air flow and reduces the efficiency of your system.

Your air conditioner removes moisture from the air in your home, and all that moisture has to go somewhere. It condenses on the AC’s refrigeration coils and runs down a drain line; most systems use a white PVC (plastic) pipe for this drain. You should periodically inspect the inside of the drain line. If it’s full of debris, clean it out, using a wet/dry vacuum if you have one, or replace it. An air conditioner can produce several gallons of water per day and will eventually flood the floor if not properly drained.

Does your home have a central humidifier? Make sure it’s turned off for summer. Also, some humidification systems have a bypass duct from the air supply to the air return on the AC unit; close the damper on this duct to prevent air from running through the humidifier.

If your walls have high and low returns (registers), switch them for summer cooling. The upper (high) vent should be open to draw hot air from the ceiling into the air conditioning system. The lower vent should be closed for the summer.

Take It Outside

Next, go outdoors for a few additional checks.

Make sure the exterior coil and fan aren’t blocked by trees, plants or other obstructions. Allow three feet of clearance at the air discharge and one foot all around the unit. Also, check that the exterior unit is level.

Keep the exterior coil clean. It’s best if your clothes dryer doesn’t vent near the exterior AC unit, but if so, vacuum lint from the exterior coil on a routine basis. If the coil is plugged with lint and dirt, hire a professional to clean the unit.

Overall Hints

Have your unit serviced yearly by a professional. If you do this in early summer, you can save money by having the heating unit checked at the same time.

Also, keep your thermostat set at a reasonable temperature – 78 degrees is a good compromise. If high humidity is the norm in your area, keep your AC unit running all the time, even when the outside temperature dips lower temporarily. It costs a lot of money and takes a lot of energy to remove moisture from the air in your home. Every time you open the windows, that moisture rushes back into your home.

Finally, keep an eye on the air conditioner. Listen for strange sounds or vibrations. As with any mechanical system, it’s better to catch a problem in its early stages rather than waiting until a crisis develops.

Just a little bit of maintenance will ensure that your central air conditioner stays efficient and keeps your home comfortable. And in the summer, that’s really cool.

Chill Out: Energy-Saving Do’s and Don’ts

DO

• Close off unused rooms, and close vents in those rooms.
• Make sure furniture doesn’t obstruct air conditioning vents.
• Block the sun with shades, blinds or draperies.
• Consider installing louvers or awnings outdoors.
• Keep heat-producing appliances like lamps or TVs away from the thermostat. Their heat fools the thermostat and makes the AC unit run overtime.
• When preparing meals, use the microwave rather than the oven.

DON’T

• When you first turn on the AC, don’t set the thermostat lower than the desired temperature. This won’t cool your home any faster; it will only lower the temperature more than necessary.
• Don’t run the kitchen or bathroom exhaust fans unnecessarily. They push that cool, dry air right out of the house.

Tom Feiza, “Mr. Fix-It,” is a recovering professional engineer who provides books, illustrations and home operating tools.  Visit HowToOperateYourHome.com for more information and books.