Why Does My Air Conditioner Smell Bad?

There can be a number of reasons your air conditioner smells bad when you turn it on. The smell is much like laundry that got wet, and never fully dried. The musty smell has been termed Dirty Sock Syndrome, and is a problem that many homeowners face without knowing why.

Why Dirty Sock Syndrome Occurs

Dirty Sock Syndrome often occurs in areas where there is excessive humidity and high temperatures one day, and cold the next. When the weather changes rapidly, the moisture left in the air conditioning system doesn't have time to evaporate. This leads to mold and mildew growth, and an odor to go with it.

How Mold and Mildew Spores Enter the System

It is common for dirty sock syndrome to happen when you go from heating your home to turning on the air conditioning system. Dust that makes it through your air filter will flow into the air conditioning unit, all the way to the evaporator coil. When the air gets humid, the dust is a breeding ground for mold and bacteria, creating an odor that spreads throughout your home when the air conditioner turns on.

Your air conditioner can quickly fill up with dust and debris if the air filters haven't been changed, or there aren't air filters correctly installed in your air conditioning system. Without proper air filtration, you can expect odors to only get worse.

Can Dirty Sock Syndrome Hurt You?

The most common reason for the horrible smell coming from your air conditioning is that you have mold and mildew on the evaporator coil of your air conditioner. While the odor isn't going to hurt you, any mold or mildew that gets into your home can exacerbate asthma and allergies. If you are coughing frequently, or your allergies seem worse, it's time to see what is going on with your air conditioning system.

Dealing With Dirty Sock Syndrome

You will want to have a professional come and deal with your air conditioning system if you have Dirty Sock Syndrome. The evaporator coil will need to be cleaned using specific chemicals and compressed air. It is not a simple process to clean evaporator coils, and older units are even harder to deal with.

If your air conditioner continues to smell bad despite the cleaning, it may be time to have a new system installed. Other issues that can cause an odor include problems with your drain line, dirty drain pans, or odiferous debris in your air filter.

When you aren't sure what is going on to cause the odor from your air conditioning system, it's time to call a heating and cooling professional to figure out the problem. We are ready to inspect and clean your air conditioner, and recommend a replacement if needed.