The black mold in an AC unit is critical stuff!
It must be removed before it causes health problems for people susceptible to lung and breathing issues.
Mold on Window Air Conditioner Styrofoam and Other Places
Sometimes you’re aware there’s black mold in window AC units because they smell musty, or they’ve been running for a while, but you don’t know why.
People who are allergic to mold often know it’s nearby when they experience allergy symptoms – coughing, sneezes, watery eyes, asthma attacks, etc.
Other times, window AC mold is evident in the filter, housing, etc.
Don’t let mold grow. However, there are steps you can take if mold appears.
What Causes Window AC Black Mold?
Knowledge is power! Knowing the causes of window AC mold can prevent it from happening again once you’ve cleaned up your AC.
Three things are needed for black mold on a window’s air conditioner. First, we discuss taking care of this equation’s nutrition and moisture parts.
Mold spores – mold usually occurs. Most homes contain mold spores. However, they don’t pose a severe threat by themselves.
Water – When spores get wet, they start to grow and produce offspring. This is the reason the U.S. Environmental Protection Agency (EPA) states, “The way to control mold growth in your home is to control moisture.” But because your window air conditioner dehumidifies the room, eliminating humidity is difficult, and it’s why black mold on windows is so common.
Nutrients – Mold requires nutrients. It’s the reason it does so poorly on new foods in the fridge. And this also provides some clues for keeping mold off your window air conditioner. Keep your air conditioner clean to starve mold.
Mold in Air Conditioner Heath Hazards
Most people won’t be worried by small amounts of black mold on the air conditioner.
However, mold in air purifier health risks is real for pets and people with COPD, asthma, allergies, and other respiratory difficulties.
Black mold is dangerous for people and their pets regardless of general health when mold spores are breathed.
Black mold’s technical title is Stachybotrys Chartarum. As per the Centers for Disease Control & Prevention, Chartarum and other molds may cause nonspecific health symptoms.
It’s NOT essential to ascertain which mold you might have growing in your house or other building. All molds should be eliminated.
How to Remove Mold from a Window AC: Step-by-Step
Window AC cleaning supply list
- Protective eyewear
- Face mask
- Latex or non-porous gloves
- Water
- CLR or another mold removal cleaner
- Mild dish soap
- 5-gallon bucket
- Cloth
- Scrub brush
- Screwdriver
- Vacuum cleaner with attachments
- Laundry detergent
- Bleach
1. Remove and Clean the Washable Filter
This is a simple way to get you started.
If black mold is present on the filter frame, clean it with Tilex, let it sit for a few minutes, and then wipe it off.
1. If you’ve antibacterial soap, place the stopper in a bathtub, utility tub, or large sink. Fill 2 inches of water in it, then add a full dose of dishwashing liquid. Roll it to mix up the soap.
2. Remove the grille from the front of the air conditioner, remove the filter, and slide the filter out of the slot. Most grille covers contain clips; some have screws.
3. Put the soap in the soapy water (or spray it on both sides) or use Tilex. Let it sit for 15 minutes (longer is fine).
4. Rub both sides of the filter with the nylon brush. Wash the filter thoroughly before using it again. Shake it slowly to help speed up the drying. If you want to use it, attach it or smoothly towel off and let it air dry. Done!
After washing filters, turn your attention to the rest of the unit.
2. Pick A Place To Work
Move the device to a well-ventilated space where it is easy to get to either side. A picnic table outside work or a bench in the garage is two common choices.
3. Carefully Inspect the AC Interior
The grille should be off. Eliminate the screws holding the metal cover in the front of the AC – it was right behind the grille.
4. Suck it Up
Use the vacuum tube to clean loose dust, dirt, lawn clippings, etc., from inside the AC. The crevice tool might come in handy.
5. Brush The Fins
Add the upholstery brush into the vacuum and lightly clean the fins on the AC coil. Keep the brush in the same direction the fins run. Be gentle to ensure the fins don’t bend.
6. Clean The Fins
When the debris is gone from the radiator-like fins, spray-on Tilex, brush it gently, and let it sit for 15 minutes before rinsing it off with water or spraying it with a hose from a sprayer.
7. Clean The Housing
Spray off the housing – the portion that sticks out the window. Allow the cleaner to sit for a few minutes before rinsing or wiping it off.
8. See Any Mold Inside?
This is the best way to remove mold from air conditioner ducts – the passageways that cycle air from indoors throughout the device and back into your room – and those on the outside that take away heat.
Spray Tilex on the mold spots if they’re on Styrofoam insulation. Ensure the cleaner sits for at least 15 minutes before washing it off with a paper towel or cloth. If using a paper tissue, throw it away, then get a new one when needed.
9. General Interior Cleaning
Now, clean up the rest of the interior. Because it’s made to be moisture-resistant and thus doesn’t breathe well, the AC hurts. Allow the cleaner to clean. Clean it off with a paper towel or a clean cloth.
10. Don't Forget the Grill and Cover
Spray down the parts you take out. Let the cleaner sit for a few minutes, then wash or wipe off the cover.
11. Dry, Assemble & Move
Let everything dry before applying another coat. Yes, ACs should be waterproof with waterproof attachments and wiring. But it’s good to be safe.
12. Reattach the cover and grille.
13. Turn It On & Inspect
If possible, plug the AC into an outlet and turn it on for a few minutes so the cleaner’s chemical smell fills the room. You don’t have any of that in your house! It can cause allergic reactions just like mold can.
How to Eliminate Mold from Air Conditioner Ducts and other Parts
We provide detailed mold removal instructions here.
Here’s your supply list to eliminate AC mold:
Safety first
Face mask and latex or nitrile gloves. You may want to wear leather gloves when dusting the fins or interior of the air conditioner. However, there are some things you definitely shouldn’t do.
Window AC Cleaning Agents
Antimicrobial soap for the filter, Tilex, or another similar product, lists its label that says it removes mold. If you don’t have antibacterial dish soap, Tilex can clean the filter. We prefer Tilex because it’s specially formulated to kill and eliminate mold.
Cleaning Tools
A nylon washcloth, a cloth rag, a paper towel, a vacuum cleaner using a crevices tool, and an upholstery brush.
Hand tools: a Screwdriver set.
How to Avoid Mold in Window AC
If you’ve removed the black mold from the air purifier, keep it away to deprive the mold of water and food.
1) Remove Dust
Mold feeds on dirt, dust, and debris. If you vacuum away dirt, dust, pollen, etc., you can starve any mold that starts growing by removing its source of nutrition. If you use a compressor to blow dust out the AC vents, it might also help. Some people cover the AC area with towels to prevent the air conditioner from turning off when it’s not in use.
2) Use Fan Mode to Dry the Inside of the AC
Some window ACs have a fan option. However, the compressor won’t turn on to transfer heat, so the fan will blow. Once you’ve cooled down the room, turn on fan mode.
This will dry out your AC unit, which could cause it to fail. And since the EPA reminds us that moisture management is the key to mold control, you should probably take care of that before it gets too bad.
3) Clean Your Window AC Several Times In-Season
If you live in a hot climate, especially one that’s humid too (like Florida), clean your air conditioning unit at least twice each year. Check it every month.
If your air conditioner doesn’t get much use during the summer, cleaning it once might be enough unless you or someone in the family is particularly sensitive to mold.
Is Mold a Problem in your Residence?
If mold seems to be plaguing your house, there’s probably a problem somewhere.
Is Mold In Your Central AC System?
If you own a central air conditioning unit, mold can grow in your ducts.
This is particularly true if your ducts are too small and your air conditioner or heater is too large.
These issues may not allow the dehumidification procedure to go through its full course. Water contracts on cold surfaces, dust mites, and mold spores have all they need to grow.
We highly recommend having the machine checked out by an HVAC technician.
Getting two professional quotes on how to solve it is a fantastic idea.
Is Mold Inside Your Home or Building?
You should try to get rid of mold in your home.
If that’s not feasible this time, or until it’s done, an air-purifying device designed to eliminate mold spores from the air would be an excellent short-term solution.
Once the mold has cleared up, the air purifier should keep your air cleaner and easier to breathe.
I’m a degreed ME (mechanical engineer) who is passionate about machines of all kinds. I created MachineWonders.com as a way to connect with others who love machines like me – or need help choosing one for their needs, application, or situation.
