Cabin Air Filters: all the dirt (and dust)
Recently, a friend asked, “How often do you really have to change the cabin air filter? At every single oil change they try to sell it to me. My dad says you can pull it out and vacuum it instead. Not sure?”
Ok, here’s the deal with cabin air filters, sometimes called micro filters or pollen filters: there isn’t a set mileage (like with oil) that they need changing. It is certainly great for your mechanic to check it at every oil change, but unless you live somewhere with extreme dust or other airborne particles, you probably won’t need it changed every time.
Cabin air filters are designed to filter the air being brought into the interior of your car and remove not only large pieces of debris (bits of leaves, bugs), but also microscopic particles like pollen. The more of these that are present in your driving environment; the more they build up in the filter. A full/clogged filter will put more of a strain on your car’s A/C system, making it work harder to bring you fresh air.
For example, the brand we use for German vehicles, Mann, has 2 styles of filter. One is a Particulate Cabin Filter and the other is an Activated Charcoal Cabin Filter.
-The Particulate filter “Removes spores, pollen, particulates, bacteria, fungi, and road dust. Laboratory tests confirm that up to 95% of dust particles and pollen are almost completely retained.”
-The Activated Charcoal filter “Consists of a nonwoven-based particle filter media, an activated charcoal layer, and a carrier media to improve stability. Removes spores, pollen, particulates, bacteria, fungi, harmful gases, and road dust. Laboratory tests confirm that up to 95% of dust particles and pollen are almost completely retained.”
In regards to vacuuming your filter, yes, you can, but the vacuum is only going to get the bigger pieces. It will not remove the fine particles that become embedded within the fabric of the filter. Vacuuming may help extend the life of your filter slightly, but it isn’t going to take you from full to like-new clean.
Visually inspecting your cabin air filter on a semi-regular basis is a good way to know if you need to replace it. If you don’t know how to remove it and check yourself, ask your mechanic. They can show you where the filter is located and how to access it, or they can let you look at the filter when they have it removed.
We recommend changing your cabin air filter on average once per year. Inspecting it during high pollen seasons (Fall and Spring) is typically a good rule of thumb.