Mold can easily grow in window AC units, especially in vents where wet dust collects.
Window air conditioning units are excellent resources for those living in areas where temperature and humidity makes residing or working indoors uncomfortable. While window air conditioning units are less expensive than central air conditioning units, they can develop mold when not in use, especially if there is a buildup of dust on the vents. If this dust gets wet, it becomes a good growing medium for mold. But with the proper tools and cleaning method, you can remove the mold from your window AC unit and restore the quality of your indoor air.
Put on protective gloves and a protective mask.
Unscrew the air conditioner’s grill. This is located on the outside front of the air conditioner unit. When the grill is off of the unit, the unit’s filter will be exposed. If it is a disposable filter, simply discard it as you will be able to replace it with a new filter. If it is a reusable filter, soak it in a solution of hot water mixed with a teaspoon of mild detergent for 15 minutes to clean off any dust, debris or mold. Rinse it in clean water and allow it to air dry before replacing it at the end of the unit cleaning.
Remove the screws that attach the unit’s metal covering. Lift it up and off of the unit once you remove the screws.
Clean the evaporator, located in the front of the unit. It looks like a set of aluminum fins. Clean any mold, dust and debris from the fins by brushing it gently with a soft-bristled brush. Brush up and down so you don’t bend the fins. If you accidentally bend one of the fins, you will need to bend it back with a fin comb, which you can purchase from your unit’s manufacturer or at a hardwood store.
Spray the evaporator with an HVAC cleaner or any general-purpose solvent. Let the cleaner sit on the evaporator for 10 to 15 minutes before wiping the fins with a clean, soft cloth.
Wipe mold and other debris off of the fan blades using a soft rag that is lightly moistened with oxygenated bleach. Do not bend the blades.
Reassemble the unit in the reverse order you disassembled it. Before you reattach the grill, replace the unit’s filter or install a new filter on the grill.