The cabin air filter (CAF) is a fairly new component installed on many newer vehicles. Many car owners may not even realize they have one until a maintenance service facility points it out to them. Cabin air filters were designed to prevent pollutants and allergens from entering the passenger cab. Studies showed that the air inside a vehicle can be six times more polluted than the air outside. As is the case with most types of filters, the CAF can become clogged and require changing to optimize its intended performance.
Finding the cabin air filter can prove to be more challenging than actually replacing it. Many vehicles place the filter in the air intake housing behind the glove box or beneath the passenger side dashboard. In most cases, this requires the removal of a kick panel or the glove box or both to reveal the access panel for the CAF.
While this can be a simple procedure on some vehicles, others may have more complicated procedures on how to remove the glove box and may have other components in the way, such as wire harnesses to the air intake housing.
Other vehicles place the CAF inside the windshield wiper cowling located at the back of the engine compartment. This location generally requires removing the cowling to obtain access to the filter. Some models may even provide an external panel without requiring the removal of the cowling.
Once the glove box, kick panel or cowling is removed, most filters have an access panel door that slides out. The filter commonly sits inside the panel that may also act as a tray for the filter. Other models feature two filters, but purchasing the replacement filter will help you identify if you have a dual-filtered model or not. When dual filters are present, the first filter needs to be removed, usually by pulling down on the front of the filter. The inside filter is often slid along the channel toward the position of the first filter and then pulled down and removed.
Note the air flow arrow on the side of the filters you're replacing. Cabin air filters feature directional air flow position and will not be effective if placed incorrectly. The new filters will also feature the directional flow indicator, usually with an arrow pointing toward the way the air should flow through the filter.
Cabin air filters generally last between 15,000 and 30,000 miles. This depends on what types of roads you drive and how much pollution is in the air. Cars that drive in heavily polluted cities with a lot of smog or on lot of country dirt roads may want to replace them more frequently.
Higher-quality filters can be purchased and last longer. Some CAFs are available as reusable filters, but requiring cleaning maintenance. The cost of the filter is much more than the disposable kind and the cleaning kits are also pricey. The maintenance they require makes their intention seem to defeat its purpose. Although made a high quality, they won't save you any money in the long run. A good aftermarket CAF under a quality name brand like Wix or Fram will suffice.
The maintenance schedule provided with your vehicle will tell you how often you should replace the filter.
