The cabin air filter prevents dust, pollen, and other debris from entering the passenger compartment through the climate control (HVAC) system.
How does the cabin air filter work?
Typically made of paper or foam suspended in a plastic frame, the air filter media catches the dirt and debris that comes in through the heating and ventilation air intake. Some high end vehicle have carbon activated filters that help eliminate fumes and odors from incoming air.
Musty and moldy odors can often be resolved by replacing the cabin air filter.
What are the symptoms related to a bad cabin air filter?
Deceased airflow from the climate control system may be noted with a clogged cabin air filter. There may also be a musty or moldy odor emanating from the vents as moisture becomes trapped in the system housing and ducting.
A vehicle can be driven with a dirty cabin filter. However, decreased climate control performance, or unpleasant odors may be noted if the replacement interval is ignored for too long. If left for too long, the bacteria that remains even after the filter is replaced will continue to leave a noticeable smell.
How often do cabin air filters need to be replaced?
Replacement intervals vary greatly by vehicle and driving conditions. Manufacturers often recommend that the cabin air filter is replaced in alternation with the engine air filter. We see this performed approximately every 40,000 miles.
How are cabin air filter issues diagnosed?
A visual inspection of the filter will be sufficient. The technician will access it by removing plastic cowling in the engine bay, or through access panels underneath the dashboard, and removing the filter. The climate control housing will be inspected for road debris, and the filter will be assessed for cleanliness.
How is a cabin air filter replaced?
The procedure is the same as the inspection. The technician will assess the climate control filter housing and remove the cabin air filter. Typically the filter is a cartridge that can simply be swapped for a new one. Some high end cars may have two filters that need to be changed at the same time.
The cabin air filter prevents pollen and dirt from entering the passenger compartment and should be replaced every year or every 10–15,000 miles.
The cabin air filter may also be referred to as a pollen filter, micro filter, or an air conditioning filter.
