Bad Smell From Cars Air Conditioner

Removing and Preventing Musty Odor in Vehicles AC

Jul 26, 2009

What causes that musty smell in the cars air conditioning vents? Find out how to prevent and methods of getting rid of that musty air conditioning odor.

That mildew smell coming from the air conditioning could be caused by fungus growth in the cars air conditioning system. As the odor permeates through the interior of the car it may also be absorbed in the seats and carpeting of the car. Knowing what causes the mildew odor will help to prevent the smell from reoccurring.

What Causes That Musty Car Air Conditioning Smell?

The real simple answer is water condensation. As the air conditioning systems is being used it builds up water condensation that can settle in the cars evaporator core housing. The evaporator core is similar to the coils on the back of some older refrigerators.

It’s surround by a black case (housing) and as the evaporator drips water from condensation it settles in the housing and becomes stagnated, causing a mildew type odor.

How to Get Rid of the Cars Musty Air Conditioning Smell

Many auto repair shops have a service that will get rid of the foul odor. Some auto parts stores also have a kit available that can rid the car of the musty smell. There are some pressurized cans of foam out there that foams up inside the evaporator core housing and scrubs the inside of the housing and core. This method requires a hole to be punched in the evaporator core housing. The foam works its magic and then dissolves and leaks back out of hole punched in the housing.

A better method is to have a professional auto technician use a sonic system that actually creates a fog inside of the car. The cars air intake in the ac system sucks in the fog and the fog is distributed throughout the ac system killing the bacteria. This type of system also soaks into the cars interior carpeting and seats and leaves the interior smelling fresh and clean.

Preventing Mildew Odors From the Cars AC System

Since the smell is caused by condensation, the best way to prevent the smell from reoccurring is to make sure the condensation dries out. The cars ac controls (on the dash) allows for closed and open circulation of the vents. Some cars have a closed/open circulation button on the ac controls. For cars that do not have a closed/open circulation button, max ac is closed circulation and normal ac is open circulation.

When the ac is in closed circulation mode (or max air), the air is circulated inside the vehicle. In normal ac mode, air from the outside of the vehicle is circulated through the ac system. When the cars engine is turned off and left in closed circulation (max air), the vent doors stay closed allowing the condensation to stagnate.

There are times when preventing the outside air from entering the cabin of the vehicle is beneficial, especially if there are contaminants in the outside air like dust, smoke or smog. Never allowing outside air from entering the air conditioning system will more that likely result in that nasty musty smell.

Serving the air conditioning system as routine vehicle maintenance will also help the smell from reoccurring. Following these simple instructions will help make the driving experience that much more enjoyable.

The copyright of the article Bad Smell From Cars Air Conditioner in Car Care/Ownership is owned by James Clausen. Permission to republish Bad Smell From Cars Air Conditioner in print or online must be granted by the author in writing.