How to Prevent Mold in Window Air Conditioner?

If you’ve ever found mold in your window air conditioner before, chances are you’re adamant about preventing it from ever happening again. But what exactly do you do to prevent mold growth? The answer is crystal clear. 

There are several steps one can take to prevent mold growth in a window air conditioner, including:

  • Turning on the AC’s humidity control setting (if applicable)
  • Keeping the AC unit on
  • Keeping the unit free of dust
  • Deep cleaning the AC unit periodically
  • Using white vinegar spray

Moldy air conditioner units are common, but this doesn’t have to be the case. Keep reading if you want to learn more about how to prevent mold in your window air conditioner, helpful information about mold, and more!  

Prevent Mold in Your Window Air Conditioner

Preventing mold growth in your AC is not an insurmountable task. The following sections will reveal to you in detail the steps that you should take to prevent mold in your window AC. 

Toggle On the Humidity Control

Humidity is a significant driver of mold growth- if the humidity in the room is high, mold growth will be accelerated.

To prevent a moldy mess, you’ll need to keep the humidity level in check. Not every window AC unit comes with a humidity control, but many of them do.

Look at your AC unit closely and see if there is a humidity setting. If your AC is equipped with humidity control, turn it on and set the humidity level to 30-50%.

This humidity level is perfect, as it will keep you comfortable without encouraging mold growth. 

If you haven’t yet bought an AC unit, make sure that you purchase a model that allows you to control the humidity setting. 

Keep the AC Unit On

A big mistake that people make with their window AC units is turning them off when you’re not home.

When you leave your home and turn off your AC, three things happen: 

  • The home is left without airflow
  • The temperature in your home rises
  • Moisture begins to build within the AC unit. 

This creates the perfect breeding ground for mold. 

To prevent this, do not ever turn your AC off. Chances are your AC unit has an “auto” mode.

This mode sets your home’s temperature at a constant, while ensuring that your AC won’t develop mold. Your AC’s “auto” mode is a cost-saving measure because of the way that it works. 

How “Auto” Mode Works

The machine’s compressor and fan work to bring your room to the desired temperature, turn off when the temperature is reached, and turn back on when the temperature falls.

This saves you money on your energy bill vs. leaving your AC on the “cool” mode. (Source: Cielo)

Don’t despair if your AC unit does not have an “auto” mode. You can simply continue to run your air conditioner on the “cool” setting while you aren’t at home.

While this is a less desirable option, it is better than allowing your unit to develop mold. 

Keep the Unit Free of Dust

Dust and mold go hand in hand. So, the dustier your AC is, the greater the chances of mold growth. 

But how do you keep your AC unit free of mold? You break out the vacuum, of course! 

After turning off the unit, use the vacuum cleaner hose to suck out any dust from the unit (and around the unit as well).

Pay attention to cracks and crevices that could easily be missed. 

Not only should you clean the outside of the air conditioner, you should take the front cover off of the unit and vacuum the filter.

It’s important not to use your vacuum’s brush attachment, as this could damage the filter. 

Cleaning your AC is not a one and done deal. It is advisable to inspect your air conditioner unit so that you can spot dust and get rid of it quickly. 

Deep Clean the Unit When Necessary

Dust is not the only culprit in the growth of mold. A deeper clean may be necessary if you find that there’s heavy gunk or dirt inside your air conditioner.

Grime can lead to mold really quickly, and if you want to avoid mold in your AC, you’ve got to start off with a clean unit.

In cases where your AC needs a deeper clean, you should take the following steps to clean it thoroughly: 

  • Always turn off the AC unit first and disconnect it. You don’t want to damage the unit. Some may want to take the entire AC unit down, but this is not necessary in most cases. 
  • Make a cleaning solution for the filter. The best way to clean an AC filter is to use water and a dish soap that isn’t too harsh. Fill a large container with enough water to completely submerge the filter and add several drops of a mild dish soap. The water should have a liberal amount of soap in it. 
  • Clean the filter. If the filter is really grimy, you may need to allow it to soak in the soapy water for up to an hour. If it’s not too dirty, you can simply use your hands to scrub away the debris. Rinse the filter and allow it to air dry. 
  • Wipe down the inside of the unit. While you’re waiting for the filter to air dry, grab a soft cloth (microfiber works fine) and wipe out the inside of the AC unit. Use gentle pressure so as not to damage the inner parts. 
  • Put the AC unit back together. Only reassemble after the parts are dry. If you put the AC unit back together without having fully dried the parts, mold can develop. Once the AC is reassembled, plug it back in and turn it on. 

If you perform regular maintenance on your AC unit, you should not have to go through the above steps too often.

However, it’s important to know how to clean it appropriately should the need present itself. 

Spray Your AC with a White Vinegar Mixture

A lesser-known preventive measure that you can take to prevent mold is to make a DIY white vinegar spray.

While white vinegar is known to get rid of existing mold, it can be used to keep it from developing in the first place. 

Simply mix one part white vinegar with one part water in a spray bottle. Lightly mist your AC unit (while it is not plugged in) with the mixture, but make sure that you allow it to dry before powering on your unit again. 

How Mold Grows in an AC Unit

Knowing the science behind how mold grows is helpful when trying to understand how to prevent mold growth. 

In order for mold to grow, it must have both moisture and nourishment (via an organic food source).

Moisture comes from within the AC unit, where water leaks and spills are common, and dust (which houses organic particles) is mold’s most common food source. 

So, when you leave the air conditioner off while you’re out of the home, dust builds and settles within the unit, along with any moisture/humidity that manages to accumulate within the machine. This creates a heavenly environment for mold. 

Why Mold Prevention is Important

You probably know enough about mold to know that you don’t want it in your AC.

However, there are many reasons why you should prevent mold in your AC unit, including: 

Mold Can Make You Sick

According to the Centers for Disease Control and Prevention (CDC), mold can cause the following ailments in people: 

  • Congestion (stuffy nose) 
  • Wheezing
  • Eye problems (itchy, watery eyes)
  • Shortness of breath and fever (in severe cases)

It’s important to note that not everyone who comes into contact with mold will have these health problems, but those who are sensitive to mold could have the following reactions. These health risks can be serious, making mold prevention in your AC a big deal. 

AC Units Spread Mold Efficiently Through Your Home

We don’t want mold anywhere in our homes, and mold has the potential to be dangerous whether it’s on your walls or behind the toilet.

But when it’s in the AC, it gets blown all over your house, increasing the chances that you’ll come in contact with it on a regular basis. 

Even though for some, the cleaning steps above may seem too involved, the health of your family is worth the trouble. 

Mold is Difficult to Eradicate

Once mold has found a home in your AC, it’s there to stay in most cases. The moment that you recognize those black mold spots, it may already be too late.

Moldy window AC units need to be replaced more often than not. This is specifically why mold prevention is preferred over fighting existing mold in an AC. 

Final Thoughts

Now you know exactly how to prevent mold growth in your air conditioner unit, why mold grows in your AC, and reasons why you should prevent mold in your unit. Use this article as your guide on how to keep your air conditioner clean and mold-free.

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