What Happens When Your Car AC Filter is Dirty?

Learn what happens when your car AC filter is dirty and how you can prevent these issues by regularly checking and replacing your car's cabin air filter.

What Happens When Your Car AC Filter is Dirty?

A dirty air filter can have a significant impact on your car's performance. It can cause the engine to work harder and less efficiently, resulting in reduced fuel economy and dirty emissions. In extreme cases, the clogged filter can completely obstruct the airflow, either by causing the fan motor to fail or by sucking the filter out of the housing along with all the debris that leaks out. One of the most common symptoms that indicates that a cabin filter needs to be replaced is reduced airflow.

The reduced airflow will appear in the form of less air being expelled from the air conditioning system grilles. When the filter is dirty or clogged, less air can pass through and the air that can pass through requires more effort than normal. Not only will this cause the air conditioning system to operate less efficiently, but it will also cause the engine to run less efficiently. A dirty air filter also makes the AC fan motor work harder. This can cause it to burn out and need to be replaced.

In addition, a clogged cabin air filter works less efficiently and consumes more energy. This puts the alternator to the test, something you don't want to happen in your vehicle. A faulty cabin air filter also cannot capture particles efficiently, and the cabin may get dirty and smell bad. If you haven't cleaned or changed the filter in a long time and your air conditioner doesn't blow cold air like before, it could mean that the system has frozen. Dirty filters restrict cold air flow, which can cause it to build up inside the air conditioner.

The end result could be ice formation on the coils. But how do you know if it's obstructed? Here are three signs that the cabin filter is clogged so you know: increased fan noise, little improvement in airflow, and an increase in odors coming from your vehicle's ventilation grilles. This can also be a potential sign that the AC filter may have been damaged or broken in some way, and is allowing unfiltered air to enter the cabin. A dirty air conditioning filter will not only hinder your car's HVAC system, but it will also dirty the inside of the windshield and become a breeding ground for different germs and bacteria that will release an unpleasant musky smell inside your vehicle. Believe it or not, the cabin filter can affect your air conditioning system and the air conditioning can have a strong impact on the power of the entire vehicle. If you notice any unusual odors coming from your vehicle's ventilation grilles, it may be a sign that the cabin air filter needs to be replaced. An increase in fan noise may be due to air intake from large materials or a dirty cabin air filter. The best way to prevent these issues is to regularly check and replace your car's cabin air filter.

Areas with above average humidity may need to replace the cabin filter sooner, as a musty odor is likely to develop. After locating the cabin filter (some vehicles, such as many Mazdas, have more than one), gently pull it out of its holder and place it on the floor or on a work table. Alternatively, take your car to a Firestone Complete Auto Care near you to have a professional technician ensure your cabin air filter is fresh and clean. The interior of your car becomes safer, the air is easier and more pleasant to breathe, and the vehicle is comfortable to drive.