Did you step into your car to go to work and notice a growing, funny smell? Or is there dust collecting around the interior? It may be time to replace your cabin air filter.
New cars are increasingly equipped with cabin air filters that remove particulates, and sometimes odors, from the air that enters the vehicle through the heating, ventilation, and air conditioning (HVAC) system. These filters are crucial in maintaining air quality inside the vehicle, ensuring a cleaner and more comfortable driving experience.
Learn why cabin air filters are important, the types available, and signs indicating when you need cabin air filter replacement.
Why Are Cabin Air Filters Important?
While cabin air filters are usually standard equipment on premium models, other cars make them available as a stand-alone option or part of an option package. Some luxury cars have two or more cabin air filters.
While cabin air filters may not be standard on all vehicles, they offer significant benefits for passenger comfort and safety.
- Remove contaminants: The types and sizes of contaminants a cabin air filter can trap vary with the specific filter design. However, a general list includes dirt, dust, leaves, twigs, insects, soot, smog, mildew, pollen, mold, spores, fungi, bacteria, germs, rodent droppings and other undesirable debris.
- Improve vehicle safety: The Filter Manufacturers Council estimates that 40 million Americans suffer from allergies caused or worsened by airborne particulates. By removing those contaminants, a cabin air filter can reduce or eliminate symptoms such as sneezing, blurred vision, runny nose, and headaches that could distract a driver and result in a collision.
- Protect vehicle interior: By trapping dirt and dust, the filter helps prevent the accumulation of debris on interior surfaces, thereby extending the lifespan of your car's interior.
Cabin air filters are more than just a convenience. They play a vital role in maintaining clean air, enhancing driving safety and extending the lifespan of your car.
Signs You Need a Cabin Filter Replacement
Your car's cabin air filter is critical for maintaining clean and fresh air inside the vehicle. There are three factors to consider when determining if you need to replace your car's cabin filter:
- Mileage: Factory-recommended intervals for replacing cabin air filters range from 15,000 to 30,000 miles. Ask your auto repair shop or check your auto's owner's manual for exact mileage specifications.
- Levels of fine particulate matter: You may need to replace the filter more frequently if you drive in an area with higher-than-normal dust levels, pollen and other airborne debris. Many motorists are shocked when they see how many contaminants cover the surface of a cabin air filter that has been in service for an extended time.
- Performance: Symptoms of a restricted cabin air filter include reduced airflow through the HVAC system, windows that fog up easily and are hard to defrost, and persistent bad odors. A restricted cabin air filter also places a greater load on the ventilation fan and can shorten its service life.
Cabin Filter Types
Most cabin air filters have a pleated filtering medium that looks like paper but is actually a more complex material made of natural and/or synthetic fibers. The filter's physical characteristics trap most contaminants, and in many designs, the air passage over the filter creates an electrostatic charge that helps attract and trap smaller particles.
Quality filters may have several layers that support the filtering medium and offer different types and degrees of filtration. Cabin air filters vary in quality, and their price reflects this. A basic filter might cost $15 at a local auto parts store, while a premium original equipment part from a car dealer could be $50 or more.
Standard Cabin Air Filter
Standard cabin air filters are typically around 98 percent efficient at trapping particulates in the 5-100 micron range. This includes the majority of contaminants, but smaller particles like mold, spores, soot, and tobacco smoke can still pass through.
HEPA Cabin Air Filter
High Efficiency Particulate Air (HEPA) filters can trap even finer particles. One major supplier claims its premium HEPA cabin air filters have a filtration efficiency of 99.97 percent at 0.3 microns based on standardized industry testing. While they cost more, HEPA filters provide the ultimate protection against airborne particles.
Carbon Cabin Air Filter
Besides filtering particulates, many cabin air filters are chemically treated with activated carbon, giving them a gray appearance and helping to remove various odors. These include exhaust gas smells such as ammonia, sulfur dioxide, nitrous oxides, hydrogen sulfide, and benzene from incomplete combustion. Some cabin air filters supplement carbon with baking soda to neutralize a wider range of smells, including odors from the human body, wet dogs, and mildew.
How to Replace Your Cabin Air Filter
Most cabin air filters can be replaced in less than 15 minutes without tools, although some take a little longer and may require removing fasteners that hold the glove box or interior trim panels in place. If you need help replacing your filter, it's a good idea to check with your local auto repair shop during a car tune-up.
- Locate the cabin air filter compartment: Cabin air filters are in the ductwork that delivers outside air to the HVAC system. In some cars, the filter is in the engine compartment near the base of the windshield. In others, it is located under the dash or behind the glove box.
- Remove the old filter: Locate the compartment cover, which is likely screwed or clipped into place. Remove the cover and take out the old filter. While the compartment is empty, vacuum out any loose debris.
- Install the new filter: Ensure the new filter matches the correct type and size of the old filter. Typically, there are arrows on the frame to guide you in orienting the filter correctly. Slide the new filter into the compartment; it should fit snugly without being forced.
- Secure the compartment: Replace the cover and snap it back in place. Tighten the screws or make sure it's correctly clipped in.
There is also good news for some drivers whose cars came without a cabin air filter. Many automakers use the same HVAC ductwork for every trim level of a given model to reduce the number of different parts they have to manufacture.
If your owner's manual mentions cabin air filter replacement, it's likely your car is equipped to accept one, even if a filter was not installed at the factory. By following the replacement instructions, you can determine whether the ductwork contains the necessary filter housing.
FAQ
Below are frequently asked questions about car cabin air filter replacement.
How Much Does A Cabin Air Filter Replacement Cost?
The cabin air filter cost varies depending on the make and model of your vehicle, and whether you choose to have it replaced at a repair facility or replace it yourself. On average, you'll likely pay between $20 and $50 for a cabin air filter replacement, but it may be higher for luxury vehicles.
How Often Should You Change Your Cabin Air Filter?
The recommended maintenance interval for changing your cabin air filter depends on your car and driving conditions, but it typically ranges between 15,000 and 30,000 miles.
In addition to following the recommended mileage interval, consider replacing your cabin air filter if you notice any of the following signs:
- Reduced airflow from the vent
- Persistent bad odors
- Dust building up inside the vehicle
To find your car's exact mileage, check the owner's manual or ask your auto repair shop.
Can You Replace the Cabin Air Filters Yourself?
Depending on your comfort level and vehicle type, you can replace the cabin air filter yourself. While it's generally not complex, some vehicles may require additional steps, such as removing trim panels. Consult your manual beforehand to ensure you complete the steps correctly or find a video tutorial online specifically for your car model.
If you'd prefer to avoid any mistakes during installation or simply want someone else to check your filters, including your engine air filter, you can take your vehicle to an AAA-Approved Auto Facility.
Replace Your Cabin Air Filters with AAA Auto
AAA recommends that you plan ahead for vehicle service by finding an auto repair shop and technician you can trust before they need them, and include regular cabin air filter replacement in your maintenance routine.
AAA members can find information on nearly 7,000 Approved Auto Repair facilities that have met AAA's high standards for appearance, technician training and certification, insurance coverage and customer satisfaction.