How to Get Rid of the Musty Smell in Your Car's Air Conditioning

It's a pretty easy fix.

By Devin Pratt

Few things are as nice as a car's air conditioning on a hot summer day. But what to do when the air coming out of the vents smells like a sweaty sock?

"What you're probably smelling is condensation coming from the evaporator inside the heating and cooling system," says Jake Fisher, Consumer Reports' senior director of automotive testing. “Basically, water collects in that area and if it sits long enough, it creates the musty smell,” he adds.

Most of the water should leave your car through the evaporator drain under the underbody of the vehicle. “You've probably seen a small puddle of water under the bottom of your car on a hot, humid day,” Fisher explains. But sometimes, some of it accumulates on the evaporator, and if it stays there for a while, bacteria and mold will grow and it will even smell in the cabin of the car. But there is a fairly easy solution.

First, turn on the car's interior fan on low setting and open the car windows. Get a disinfectant like Lysol or some type of AC disinfectant product from an auto parts store and spray it in the area called the plenum.

The plenum is a box that connects to the HVAC system (heating, ventilation, and air conditioning system), and can be found at the base of your windshield at the height of the windshield wipers. Right there you will see some vents that are the plenum of your car. That's where the air coming into your heating and cooling system comes from.

It liberally sprays the cleaner on both sides of the plenum intake vent and is drawn into the system by the fans themselves, where it will kill bacteria and help eliminate musty odors. At that time it is preferable to keep the windows open to help ventilate the car. If you have a cabin filter, remove it before spraying the sanitizer to help it move through the system. It could also be a good time to change it, because a dirty filter prevents optimal airflow. Cabin filters are usually quite easy to reach, often located behind the glove box door.

To keep your vents in good condition during the summer, turn off the air conditioning and let the fans run for a few minutes before turning off the car's engine. This will help remove some of the moisture that forms on the air conditioning vents.

Editor's note: this article has been adapted from an episode of Talking Cars.

Consumer Reports is an independent, nonprofit organization that works side by side with consumers to create a fairer, safer, and healthier world. CR does not endorse products or services, and does not accept advertising. Copyright © 2023, Consumer Reports, Inc.

Consumer Reports has no financial relationship with the advertisers on this site. Consumer Reports is an independent, nonprofit organization that works with consumers to create a fair, safe, and healthy world. CR does not endorse products or services and does not accept advertising. Copyright © 2023, Consumer Reports, Inc.

Author Profile

Nathan Rivera
Allow me to introduce myself. I am Nathan Rivera, a dedicated journalist who has had the privilege of writing for the online newspaper Today90. My journey in the world of journalism has been a testament to the power of dedication, integrity, and passion.

My story began with a relentless thirst for knowledge and an innate curiosity about the events shaping our world. I graduated with honors in Investigative Journalism from a renowned university, laying the foundation for what would become a fulfilling career in the field.

What sets me apart is my unwavering commitment to uncovering the truth. I refuse to settle for superficial answers or preconceived narratives. Instead, I constantly challenge the status quo, delving deep into complex issues to reveal the reality beneath the surface. My dedication to investigative journalism has uncovered numerous scandals and shed light on issues others might prefer to ignore.

I am also a staunch advocate for press freedom. I have tirelessly fought to protect the rights of journalists and have faced significant challenges in my quest to inform the public truthfully and without constraints. My courage in defending these principles serves as an example to all who believe in the power of journalism to change the world.

Throughout my career, I have been honored with numerous awards and recognitions for my outstanding work in journalism. My investigations have changed policies, exposed corruption, and given a voice to those who had none. My commitment to truth and justice makes me a beacon of hope in a world where misinformation often prevails.

At Today90, I continue to be a driving force behind journalistic excellence. My tireless dedication to fair and accurate reporting is an invaluable asset to the editorial team. My biography is a living testament to the importance of journalism in our society and a reminder that a dedicated journalist can make a difference in the world.