Routine Air Conditioning Service & Maintenance

Neglecting necessary AC maintenance ensures a steady decline in your air conditioner's performance and a steadily increase in its energy use.

Properly maintaining your AC system will lower your energy-consumption and repair costs, prevent breakdowns, and prolong the life of your equipment. Some air conditioner service jobs should be left to the professionals, but as a homeowner in Fairfax or Manassas, VA, you can do a lot to prolong the life of your equipment and keep it running at peak efficiency.

Air Conditioner Filters

The most basic but important maintenance task to ensure the efficiency of your air conditioner is to routinely clean or replace the air filters. Clogged, dirty filters block normal airflow and reduce an AC's efficiency significantly. With normal airflow obstructed, air that bypasses the filter may carry dirt directly into the evaporator coil, which will impair the coil's heat-absorbing capacity.

Filters are located somewhere along the return duct's length. Common filter locations are in walls, ceilings, furnaces, or in the air conditioner itself. Some types of filters are reusable; others must be replaced. They are available in a variety of types and efficiencies. Clean or replace your air conditioning system's filter or filters every month or two during the cooling season. Filters may need more frequent attention if the air conditioner is in constant use, is subjected to dusty conditions, or if you have furry pets in the house. If you use a disposable filter, it's always wise to keep several spares on hand.

Sealing and Insulating Air Ducts

For central air conditioning to be efficient, ducts must be airtight because an enormous waste of energy occurs when cooled air escapes from supply ducts or when hot attic air leaks into return ducts. Recent studies indicate that 10 percent to 30 percent of the conditioned air in an average central air conditioning system escapes from the ducts. Hiring a competent professional technician for air conditioner service to detect and correct duct leaks is a good investment, since leaky ducts may be difficult to find without experience and test equipment. Ducts must be sealed with duct "mastic." The old standby of duct tape is ineffective for sealing ducts.

Obstructions can impair a duct system's efficiency almost as much as leaks. You should be careful not to obstruct the flow of air from supply or return registers with furniture, drapes, or tightly fitted interior doors. Dirty filters and clogged evaporator coils can also be major obstructions to air flow.

The large temperature difference between attics and ducts makes heat conduction through the ducts almost as big a problem as air leakage and obstructions. Ducts in attics should be insulated heavily in addition to being made airtight.

Performing Outside Maintenance

Outside dirt, leaves, grass, and other debris clog the AC unit's condenser coils, straining the system.

Once a month, you should inspect an outdoor AC unit to insure that nothing is obstructing the airflow across the coil. Remember to turn off the power at the disconnect switch mounted on the wall near the unit before you do any work on your condenser unit. If your AC doesn't have a disconnect switch, turn off the breaker.

If you find that your unit is becoming dirty through normal operation, you can follow the procedures below.

Disconnect the power and check to see if leaves or other debris have collected inside the condensing unit. If so, open the unit by undoing the screws on the top panel and tipping it up. Remove any debris from the enclosure. Then, reverse the procedure, making sure to replace the screws before restoring power. Do not open the electrical panel cover. This is best left to a certified air conditioner service technician.

Check your compressor unit to make sure it is level. An unleveled unit will be nosier, less efficient, and will wear down more quickly. Check the level in both directions, making adjustments if necessary. Be careful how much you move the unit. It has rigid connections to the electrical and refrigerant lines. Too much (and it doesn't take much) movement could cause a refrigerant leak to occur.

Finally, check the condensate line for a bacterial slime that tends to grow in condensed water. The condensate line is the drain that removes water that has condensed from your indoor coil. Pour a 1:9 bleach-and-water solution through the line. Find the fitting for the hose, pull it out, and flush the line all the way to the floor drain. If the drain is difficult to reach, you may want to call your air conditioner service contractor to do the job.

Always be careful when using lawn mowers and trimmers around your condensing unit because flying debris can damage the coil and fins.