The importance of treating mold in your car’s HVAC system | Sound Driving

When people think of car maintenance, many people think of oil changes, alignments, new air filters and new windshield wipers.

When people think of car maintenance, many people think of oil changes, alignments, new air filters and new windshield wipers. It is easy to neglect the maintenance that doesn’t affect how the car runs, such as cleaning the car.

I’d like to share a story with you.

I was riding in a friend’s car and after about an hour, I noticed a sore throat developing. But the symptom that seemed to be a harbinger for a cold disappeared several hours after getting out of the car.

I mentioned this curiosity to my wife, and she told me that her mold allergies cause this same experience whenever she encounters a high-mold environment. When I mentioned it to my friend, he said his daughter cannot ride in his car because of the mold growing in the ventilation system.

I doubt my experience is unique, but the truth is that the cause and solution to mold and mildew in cars is quite simple.

The heating, ventilation, air conditioning (HVAC) system in any car is a perfect breeding ground for microorganisms such as bacteria, mold and mildew. These respiratory fiends need moisture, food and a temperature above 40 degrees. In the Northwest, they hit the jackpot in our cars.

In most newer cars, the HVAC system pulls in cold, moist air from outside, chills and condenses the air to remove moisture, which is collected under the evaporator core into a drain pan. The dry air is then blown in through the heater core. Especially during the wet spring months, the collection pan is regularly moist. When dust or debris gets into the pan, microorganisms and bacteria are able to flourish.

What people may not realize is that the remedy for this situation can be as simple as a disinfectant. For some cases, a household aerosol disinfectant can be sprayed into the system’s inlet while the blower fan is turned on. The disinfectant can destroy whatever has grown in the system and eliminate any odors. The inlet for the vent system can usually be found on the outside of the car, either under the hood or just behind it.

This method’s success often depends on the disinfectant used, the configuration of a car’s HVAC system and the severity of the infestation of mold and mildew.

When considering trying this, make sure to read and follow the product instructions carefully. Some products may damage components or the finish of the car’s interior. Most auto part stores can provide a product that is safe to use in your car.

Depending on the severity of the microorganism and/or bacteria infestation, a higher level of treatment may be required.

When my own car developed a mildew smell, I had it treated with professional-grade product to clean it up. Within a week, the smell was completely gone.

Your mechanic likely has access to professional-grade products that are able to thoroughly eliminate microorganisms within the vent system. These products are typically not available to the public due to their aggressive nature, but for an extreme infestation, these products may be necessary to successfully treat the issue.

Car maintenance is more than the engine and wheels. The cleanliness of your car can have a real impact on your physical health.

Next time you notice an odor in a car, don’t wrinkle your nose and go on with your day. Stop by the store and get some disinfectant or visit your local service center and make the health of yourself and your car a priority.

Ken Clark is the owner of Sparks Car Care in Federal Way. He can be reached at 253-874-1070, or