To breathe or not to breathe: Reasons for replacing your cabin air filter this season

FTMAbanner-2740 flattened TXT d2Spring has finally arrived here in Kalamazoo, and what that means for you, is a full onslaught of awful particulates to breathe in like pollen, dust, mold and more, guaranteed to make you simply feel miserable. Naturally, your first line of defense in your car, aside from your favorite go-to allergy medicine and closed windows while on the road, is your heating, ventilation and air conditioning system (HVAC) filter–also known as your cabin air filter.

When heating or cooling your vehicle, air is taken in through the HVAC system, where it is heated or cooled before being directed through the cabin air filter. In Chevrolets, this filter is found lodged in a precarious area behind your dashboard (and is usually accessible through the glove box), where it absorbs environmental impurities that affect the quality of air you are breathing, and surprisingly also affects the cleanliness of your vehicle.

The filter has paper folds much like an accordion, designed to catch the smallest of particulates, sometimes up to .001 microns. However, once those folds have held a couple or few years of dirt, it’s no longer able to absorb those particulates. Instead, dirty air makes its way into the cabin, accompanied by a musty smell due to dust particles attracting water and holding it onto that filter, creating a perfect storm to grow mold.  And with that, more pollen, dust, pollutants and mold begin layering on the filter and travel into the vehicle, and you’ll be breathing it all in.

Your filter’s cleanliness also influences your vehicle’s efficiency, as now, more air needs to be passed through the HVAC system to penetrate the dirty air filter. This causes an overall weak airstream you will feel coming through the vents, because the air has no where to go. And if you can’t feel it, you’ll turn the system fan or temperature up more to make up for the difference.

Think about a fan you have at home or have had in your life. There’s at least one fan you’ve come across that has a thick layer of dust collected on the blades, and every time it was turned on, you would see a small puff of dust particles float back into the air.

Now, that same fan is in your car trying to blow air into your vents. With no cabin air filter, that dust (or pollen, smog, etc) is coming straight into your car, and making its way around your vehicle. With a filter that has been well used and in need of changing, it’s almost like putting a sheet over it, with a few holes, where things will get through, but you’ll also experience little-to-no airflow.

(*Note: The filter on the left was removed from a vehicle earlier this week. The one on the right is the brand new replacement cabin air filter. Which would you prefer to filter the air coming into your vehicle?)

So again, why should you change the cabin air filter?

The easy answer is the benefit of clean air to breathe in your car without any odd smells of dust or mold, with your interior avoiding looking like any dusty item you would procure from Grandma’s attic or basement, and you and your passengers’ sinuses and allergies can have a little relief.

GM requires vehicle cabin air filters to be changed out every 22,500 miles or two years. If you live in a more polluted or dusty areas, you may want to consider changing it more often. As our Chevrolet Certified Service Technicians do inspect it during your vehicle’s Multi-Point Vehicle Inspection, you can always ask on the condition of the cabin air filter, and your service advisor can and should inform and show you the condition of your filter, especially if it is quite dirty.

Another additional benefit of a new cabin air filter,  is that air can actually get into your vehicle, and your car can and will run more efficiently to heat and cool the interior, like it was designed to do, in a reasonable amount of time. On those upcoming incredibly humid, hot 90+ degree summer days on the west side of the state, do you really want it to take nearly twice as long or more to cool down your car?

It’s a simple, inexpensive thing to change, and only so often. Plus, why not keep cool this season, as well as enjoy breathing in a little clean(er) air?

“For the Miles Ahead” blog is a weekly series dedicated to guiding friends, family and customers through their maintenance needs. If you have a question about service maintenance or car-related troubles, write to Motor Maven at

5 Comments Add yours

  1. To avoid costly repair or replacement, make your unit more energy-efficient, and save you money on electricity bills, it is a good idea to change your air filter regularly

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