Tuesday Tip: Maintain Your Centralized Air-Conditioning to Keep Your Family Cool

By Yehudit Garmaise

Instead of just hoping our air-conditioners (a/c) will continue to blow cool, clean air as temperatures soar, we can take a few steps to maintain our a/c units will keep them going strong: all summer long.

Failing to maintain air-conditioners will not only diminish their abilities to cool down rooms, but dirty air conditioners and improperly operating systems can encourage the growth of microorganisms, such as mold, which can exacerbate allergies and asthma, said Sarah Kirby, PhD, the assistant director of the NC State Extension and a profession or agricultural and human sciences at North Carolina State University.

Whether residents’ heating, ventilating, and air-conditioning systems (HVAC) are comprised of a furnace and an a/c or a heat pump, which both heats and cools,  both types of systems include interior and external units that can be maintained by informed residents.

More serious maintenance tasks, such as slow refrigerant leaks, ensuring clean ducts and proper airflow, and twice-yearly service checks, of course, should only be done by expert HVAC technicians.

In addition, residents should call for service checks on their units twice a year: just before the weather gets cold and just before the weather gets hot, Dr. Kirby suggested. 

Savvy homeowners can use the following tips not only to extend the life spans and increase the power of their cooling systems, but to save considerable money as well by increasing units’ efficiency, CNN reported.

1. Completely shut off your a/c’s power before launching your maintenance efforts. Working around electricity is dangerous, and residents must do two things to cut the power. First, look for an exterior shut-off box near the unit, and then make sure to turn off the power at your breaker box.

2. Remove dirt. Use a screwdriver or wrench to remove the fasteners on the unit’s exterior condenser/compressor. Then, remove the fan cage by lifting it away from the top of your unit. To clean leaves and other debris from the inside of your unit, use either a wet/dry vacuum cleaner or clean by hand with a damp towel. 

3. Clean the fins/circular wires. First, remove the outer covers, and then use a brush attachment on a powerful vacuum to remove all outside dirt. Then, use a garden hose to apply a gentle stream of water to clean through the fins from the inside out to remove all the built-up dirt and debris.

For particularly dirty fins, commercially available fin cleaning sprays are sold at home improvement centers. Read and follow manufacturer directions.

4. Use a butter knife or a commercially available fin-straightening tool to gently straighten the fins/circular wires so that air can flow efficiently. 

5. Clean the area outside around your unit. Once you have finished cleaning and have replaced the fan cage, rake back any leaves and debris that surround your condenser. Cut back branches and any brush that has grown within two feet in all directions to ensure proper air flow.

6. Check to see whether your compressor is level. As soil settles beneath a/c units, the pads on which the condenser sits can begin to tip. An unleveled condenser unit can cause the compressors within to fail very quickly.

7. Clean the evaporator’s coil inside the unit by finding the evaporator coil door. You may need to remove some foil duct tape and take out a few screws or bolts. 

Once inside, use a soft brush to dust off the coil, and then spray the coil with a no-rinse coil cleaner. The spray will foam up before it starts to drip into the drain pan. 

Then, clean out the drain pan with soap, hot water, and a little bleach before you pour a cup that is ½  c. bleach and ½ water down the drain to inhibit algae growth.

 If the bleach mixture drains easily, you skip the next step of cleaning the evaporator drain. 

8. Clean the evaporator drain, in which algae and mold can accumulate. If your drain is either not flowing or flowing very slowly, you can unplug it by using a wet/dry vacuum to clear the drain. Replace the evaporator coil door, and use foil duct tape to reseal, if necessary.

9. Change your HVAC system’s blower filter at least twice a year: once just before the heating season begins and once before the cooling season begins. 

10. Find your unit’s filter enclosure in the location where the large fresh air return duct enters the unit. You may need a screwdriver to turn the latch to open the door to the filter enclosure. Remove the old filter and install the new filter, ensuring to match the air-flow direction arrows on the filter to the arrows on the unit. Close and latch the door, before turning the power back on. 

11. In the fall, when you stop using your a/c, cover the top of your unit with a piece of plywood or plastic to keep dirt and debris from falling inside. 

Don’t completely cover the unit’s sides, which can cause moisture to build up inside, cause corrosion, and encourage vermin to build nests inside. 

12. Remember to remove any covers before starting up your a/c units in the late spring.