Mold In Air Conditioner

Updated: May 17, 2023 8:16 PM
What to Do When There is Mold in Your Air Conditioner

Even if you have a top-tier air conditioner, you should know what to do when there’s mold in your air conditioner. Whether you’re sensing a musty smell or have spotted mildew or visible mold growth on a surface in your AC unit, we can show you how to clean a mold infestation and get your AC unit smelling fresh again. After all, if you are wondering, why does my AC smell? mold growth could be the culprit.


  • If you suspect a moldy air conditioning unit due to musty odors, power off the unit immediately and investigate.
  • Open the air conditioner and look for signs of mold like black spots or fuzzy growths.
  • You can clean the mold materials with household cleaners or reach out to a mold removal specialist.

What to Do About a Moldy Air Conditioner

Mold exposure can be a severe health issue that causes respiratory issues, shortness of breath, skin rashes, sore throat irritation, and other allergic reactions. Black mold spores can gather in an AC unit due to the humidity levels, and it can cause symptoms of mold exposure that turn into health risks, even to people without a mold allergy.

Insider Tip

You can use soapy water in your central air conditioning system, but you can cause water damage if you get moisture inside the exhaust fans.

Contact with mold toxins can cause actual health risks and possible severe reactions, including respiratory issues and eye irritation. If you think you have a moldy AC unit, you should contact an experienced professional for mold removal services or follow this guide to combat this severe health hazard.

Mold growth can occur when your AC unit is overheating or water leaks in the system. In addition, if your AC isn’t cooling, you may have dirty air ducts and mold damage. After all, the inside of an AC unit produces the perfect conditions for mold, but regular cleanings that zap earlier signs of mold growth from a professional service provider can help mitigate heavy mold growth.

If you have any experience cleaning mold from a shower or toilet, the process isn’t much different when cleaning an AC unit. While you’re inside the machine, you can apply some AC unit oil and find the contactor, but those shouldn’t affect the growth of mold in the unit.

Power Down the AC and Inspect the Unit

Disconnect your AC unit from power before looking at the internals. You should wear gloves and a mask while checking for the presence of mold in air conditioners. You can spot mold colonies by looking for black dust or fuzzy growth inside the unit.

Removing the Mold

You can clean the mold from your AC with most household cleaners, but you can also use a white vinegar or bleach solution. Vaccum the AC unit’s internals and apply the cleaning solution with a scrubbing sponge.

Leave the cleaning solution on the AC unit for about 10 minutes, and then rinse the unit with a hose or clean, damp cloths. Let the unit dry for up to 24 hours.

How Can You Prevent Mold Growth?

You can prevent mold growth by ensuring that your AC unit runs efficiently. In addition, if you have a window unit, ensure that it is tilted towards the air conditioner’s drip pan. Lastly, do not run your humidifier while running the air conditioner. Plus, many modern AC units come with an energy saving mode, which can help to reduce your electricity bill.


Schedule mold testing to ensure that dangerous mold spores haven’t infested your home.


What does mold in AC smell like?

Some people describe the smell of mold as wet, rotten, or stale. In addition, some users describe the scent as meaty, rotten wood, or wet socks. The smell is one of the most distinct signs of mold in your home or AC unit.

What causes mold to grow in air ducts?

An aging or dysfunctional AC unit offers an excellent environment for mold growth due to heat and moisture. If your air conditioning system has poor ventilation due to dirty filters or a faulty motor, the cold air cannot flow, leading to condensation along the air ducts. The heat and moisture provide a hotbed for mold growth.

Is duct cleaning a waste of money?

While some experts suggest air duct cleaning is a waste of money, that isn’t the entire story. There are times when duct cleaning is necessary to combat the health effects of mold, animal infestation, and severe asthma symptoms.

STAT: According to a 2019 Pew Research Center survey, only 8.8% of Americans do not have an air conditioner unit. (source)

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