How to Clean Mold From a Window AC Unit?

Keeping your window air conditioning unit clean ensures fresh air quality in your home! Mold can easily build up and spread when the AC is on, which might lead to some unwanted allergies or funky smells. But don’t worry! I’ve compiled an easy, friendly step-by-step guide to help you safely clean the mold from your window AC unit and keep it from returning. Let’s make your space fresher and healthier together!

Tools and Supplies Needed

• Gloves, Mask, and Safety Goggles: Protect yourself from mold spores and cleaning chemicals.
• Screwdriver: To remove the front panel and access internal components.
• Vacuum with Brush Attachment: For removing dust and loose debris.
• Spray Bottle with Bleach Solution: Mix a solution of 1 part bleach to 10 parts water. You can also use white vinegar or a commercial mold cleaner if preferred.
• Mild Dish Soap: For general cleaning.
• Soft Brush or Sponge: For scrubbing moldy areas.
• Toothbrush: For cleaning small crevices.
• Bucket of Warm Water: For rinsing.
• Microfiber Cloths: For wiping down surfaces.
• Fan or Sunlight (Optional): To speed up drying after cleaning.

Step 1: Safety Precautions and Preparing the Area

1. Turn Off and Unplug the Unit: Always disconnect the power source before working on your AC unit.
2. Protect Yourself: Wear gloves, a mask, and safety goggles to protect against mold spores and bleach fumes.
3. Set Up a Work Area: Place a tarp or towels beneath the unit to catch any drips and debris. If possible, remove the unit from the window and work outside for better ventilation and to avoid spreading mold indoors.

Step 2: Disassemble the AC Unit

1. Remove the Front Panel: Using a screwdriver, remove the screws holding the front panel in place.
2. Take Out the Air Filter: Most window AC units have a removable filter. Carefully remove it, as it may have mold on it.

Step 3: Clean the Air Filter

1. Wash the Filter: Rinse the filter with warm, soapy water. Add a few drops of dish soap to help lift dirt and grime.
2. Disinfect with Bleach Solution: Spray the filter lightly with the bleach solution to kill mold spores. Let it sit for 10-15 minutes.
3. Rinse and Dry: Rinse the filter thoroughly to remove all traces of bleach. Allow it to air dry completely before reinstalling.

Step 4: Clean the Evaporator Coils and Blower Fan

1. Vacuum Dust and Debris: Use the brush attachment to remove loose dust and debris from the evaporator coils and blower fan.
2. Apply Bleach Solution to Coils: Spray the bleach solution on the evaporator coils, which are often a prime area for mold growth due to moisture accumulation. Let the solution sit for 10-15 minutes to kill any mold.
3. Scrub Gently with a Soft Brush or Cloth: Use a brush or sponge to scrub away any visible mold, careful not to bend or damage the coils.
4. Rinse and Wipe Down: Wipe the coils with a damp cloth to remove any remaining bleach residue.

Step 5: Clean the Drain Pan

1. Locate the Drain Pan: The drain pan collects condensation and is a common area for mold growth.
2. Scrub the Pan: Spray the pan with the bleach solution, let it sit, and scrub it with a brush or sponge to remove mold.
3. Rinse and Dry: Rinse with clean water and dry the pan to prevent further moisture buildup.

Step 6: Clean the Blower Wheel and Fan Blades

1. Spray and Scrub: Use bleach to spray the blower wheel and fan blades. Use a toothbrush to scrub any mold or grime in tight areas.
2. Wipe Down: After scrubbing, wipe the areas with a damp cloth to remove bleach residue.

Step 7: Clean the Outer and Inner Surfaces

1. Spray the Bleach Solution on All Surfaces: Spray the remaining inner surfaces and the front cover with the bleach solution.
2. Scrub with a Sponge: Scrub all surfaces with a sponge, paying attention to mold spots or dirty areas.
3. Rinse and Wipe: Use a damp cloth to rinse the surfaces, ensuring no bleach residue remains. This is important, as bleach fumes can circulate when the unit is turned back on.

Step 8: Dry Completely

1. Allow to Air Dry: Place all cleaned parts in direct sunlight, if possible, to help kill any remaining mold spores and speed up drying. A fan can also help expedite the drying process.
2. Ensure No Moisture Remains: Before reassembling, confirm that everything is completely dry. Any remaining moisture can lead to further mold growth.

Step 9: Reassemble the AC Unit

Once everything is dry, reassemble the unit by reinserting the filter, replacing the front panel, and securing it with screws. Place the AC unit back into the window if you removed it.

Step 10: Prevent Future Mold Growth

Now that your unit is clean follow these tips to prevent mold from returning:

1. Run in Dry Mode: Many window AC units have a Dry or Dehumidify mode that reduces moisture in the unit. Run this mode occasionally to prevent mold growth.
2. Regular Filter Cleaning: Clean the filter at least once a month during periods of heavy use. This keeps dust and mold spores from building up.
3. Use a Mold-Resistant Spray (Optional): Consider applying a mold-resistant coating to the evaporator coils, which can help prevent future mold growth.
4. Allow the Unit to Dry: After shutting off the AC for the day, run it in fan-only mode for 10-15 minutes to help dry out moisture within the unit.

When to Call a Professional

If your unit has severe mold buildup or if the mold smell persists despite cleaning, you may want to call an HVAC professional. Mold can grow in hidden parts of the unit, and a professional can disassemble and deep-clean areas that may not be accessible.

Following these steps will help ensure your window air conditioner remains mold-free and functions efficiently, providing clean, cool air throughout the season. If you maintain a regular cleaning schedule and follow preventive tips, you can significantly reduce the likelihood of future mold growth in your AC unit.