Cabin air filters have been included in many vehicles for more than a decade, with more than 90 percent of current model vehicles so equipped. We’ve written numerous articles about these filters and preached the merits of replacing them on a regular basis to our readers. Aftermarket filter manufacturers have tried to educate the motoring public about these filters and the need to maintain them. Yet most motorists remain blissfully ignorant about cabin air filters. Most have no idea their vehicle has one, let alone where it is located or how to replace it.
It’s no surprise, therefore, that cabin air filters don’t exactly fly off the shelf. Most only need to be replaced every two to three years or 30,000 miles. The “odor eating” variety that can also absorb and trap unpleasant smells has a recommended service life of about a year or 12,000 to 15,000 miles. But it doesn’t matter because few motorists replace these filters that often — if at all!
It’s out of sight, out of mind as far as many motorists are concerned. In fact, many are surprised to learn their vehicle has a cabin air filter when a quick lube tech, repair shop technician or service writer asks them when the filter was last replaced. “Cabin air filter? What cabin air filter? Are you putting me on? I don’t see no filter!
Yep, it’s there neatly tucked behind the glove box inside the HVAC plenum, or hidden under a little access door at the base of the windshield in the plenum area of the cowl. Just look in the owner’s manual and you’ll see cabin air filter listed as a service item in the recommended maintenance schedule. Of course, few motorists ever remove the plastic wrapper from their owner’s manual, let alone flip through the pages or read what it says. They have to rely on somebody else to remind them what needs to be serviced and when. Even then, they may totally ignore your advice. So you have to keep hammering home the message that most late-model vehicles have a cabin air filter, and that the filter needs to be replaced periodically.
What happens if the filter isn’t replaced? It becomes a trap for debris, mold and bacteria that can create unpleasant odors and unhealthy air inside the passenger compartment. A plugged filter also restricts airflow through the air conditioning, heater and defroster ducts, causing heating and cooling problems any time of year.
What happens if a motorist simply yanks the old filter out and doesn’t replace it with a new filter? They may get a face full of gravel dust the next time they drive on a gravel road with the vent, heater, defrosters or A/C on because there’s no filter to prevent the dust from blowing right through the HVAC system.
The filter also helps to protect the HVAC blower fan and air control doors from being fouled or jammed by leaves, dead bugs, dirt or other debris that enters the cowl vents and finds its way into the HVAC unit.
Cabin air filters are a bit pricey compared to some engine air filters, so there may be some reluctance to replace a filter that many customers perceive as being relatively unimportant. That’s why you need to continue your efforts to educate your customers about cabin air filters, and remind them it’s important to service this filter along with the other filters on their vehicle. It’s their health and their vehicle they are protecting when they replace a cabin air filer.
