Cleaning Mildew and Mold from AC Coils

When moisture arrives or increases in a closed-off space, mold and mildew are usually not far behind. The presence of moisture in most air conditioner coils makes for a nearly perfect environment for the growth of these toxins.

Here are a few tips, courtesy of the San Francisco Chronicle’s Home Guides section, for cleaning your air conditioner’s coils to eliminate allergens, as well as for making the system work more efficiently. Be sure to consult your owner’s manual before beginning any maintenance work to the unit, and always replace any old or used filters:

For Outdoor Units: First, turn off the power to the AC unit by unplugging it or by cutting electricity to the appropriate circuit breaker in your home’s electrical panel. Then, remove the unit’s outer housing. Use a vacuum cleaner to remove dust, debris and dirt from the condenser fins and grill. Remove the top grill, taking care not to stretch or break any wires that may attach to the unit. Use a hand broom to brush off any dirt from the evaporator coils. Spray the coils with an AC evaporator coil foaming cleaner, preferably one that’s ”no-rinse.” After 15 minutes, take a fin comb to the AC fins in order to straighten them. After an hour, reassemble the unit.

For Indoor Units: Again, cut power to the unit, as above, and remove the unit’s outer housing. Vacuum the blower and motor areas. Apply the same foaming rinse to the coils, run the fin comb through the fins after 15 minutes and then reassemble the unit after waiting for an hour.

Note that dry times are approximate and will vary depending on conditions. The idea is to make sure that the unit that you have taken pains to de-assemble has enough time to thoroughly dry so that any moisture that you’ve added as a result of the cleaning process won’t create more mold and bacteria.

As always, please feel free to contact one of our experts here at AC World with any maintenance questions or concerns!