Cabin Air Filter, Why and When To Replace?

Automotive cabin air filters

 How often do you change your cabin air filter?

The cabin air filter is typically a pleated-paper filter that is placed in the outside-air intake for the vehicle’s passenger compartment. Some of these filters are rectangular and similar in shape to the combustion air filter. Others are uniquely shaped to fit the available space of particular vehicles’ outside-air intakes. Being a relatively recent addition to automobile equipment, this filter is often overlooked, and can greatly reduce the effectiveness of the vehicles air conditioning and heating performance. Clogged or dirty cabin air filters can significantly reduce airflow from the cabin vents, as well as introduce allergens into the cabin air stream. The poor performance of these filters is obscured by manufacturers by not using the MERV rating system. Some people mistakenly believe that some of these are HEPA filters.

When you should change your cabin air filter?

Some car-care experts and filter manufacturers recommend changing them every  12,000 to 15,000 miles — at least once a year, but twice a year is necessary for maximum benefit. Moving  vehicles create a “tunnel effect” that causes pollutants inside the vehicle to reach up to six times the concentration of outside air. About 30.4 million Americans — roughly one in 10 people — live in areas with unhealthy levels of pollution.

cabinAirFilterCabin air filters clean the air entering the passenger cabin via HVAC system and have the ability to clean 100 percent of pollutants including pollen and road dust. More than 60 percent of individuals suffer from respiratory problems and 75 percent are concerned about the air quality in their vehicles. One survey reports U.S. car owners are largely unaware their automobiles and light trucks contain cabin air filters that should be changed at regular intervals. But this survey was from 2003 — the number of CAFs has increased considerably and consumers may be better educated today about CAF maintenance. The micron Air cabin air filters’ Web site provides a list of vehicles with CAFs and instructions on how to change them. Does your vehicle have a CAF? If so, how often do you change it?

What is a Cabin Air Filter?
The cabin air filter is a high particulate filtration medium that goes that is attached to the outside air intake of your vehicle’s ventilation system. This device helps to improve air quality and filter out pollution from the air that circulates inside the vehicle. Most air filters are made from a pleated paper construction, using a variety of different filtration media. Some are a cotton and paper blend, while others are basically extremely miniaturized paper filters similar to the air filter of your car’s intake system. There are some that are just a formed and shaped cotton filter in a cartridge. The cabin air filter is sometimes confused with an internal combustion air filter. The internal combustion air filter is the filter under your hood that prevents particles from getting into the engine. A driver may encounter the internal combustion air filter as a service recommendation at an oil change shop. That’s because if the air filter gets clogged or otherwise compromised, it can affect engine performance.
It’s important to recognize the distinction between these two very different types of air filters. When buying cabin air filters, you’re looking for something that’s going to help improve the air that you will be breathing as a driver or passenger in the vehicle. It’s not so much part of the vehicle’s performance gear as a health and safety device. Drivers can consider buying “green air filters” that are more sustainable and include more attention to what the inhabitants of a vehicle will be breathing.

Where is the Cabin Air Filter Located?
The cabin air filter, or air conditioning filter, is located in different places in different cars. On some cars these are easy to locate, remove and change. On others, they are more difficult to remove and change. They will all be in the air conditioning/vent system after the fan. Most of these can be found just inside a small inspection door in the cabin side of the fan housing. On most cars this will be down by where the front seat passenger’s feet are located. This area is sometimes referred to as the foot well. Refer to your car’s manual for the exact location.

Step-By-Step Guide

  1. The first thing you need to do is locate your owner’s manual to find out if your      vehicle is equipped with a cabin air filter. If you can’t find the information, then your car is probably not equipped with a cabin air filter. However, if you would like to be sure, call your favorite parts store and they can provide you with the information.
  2. When you purchase the new cabin air filter, be aware that there are 2 types of      filters. One is called the particulate; the other is called the activated charcoal. The particulate filters out road dust, bacteria, mold spores, pollen and other pollutants. The activated charcoal filters the above  mentioned and filters harmful gasses and odors. People who drive around in  gridlock or have an odor problem might consider buying the activated  charcoal, though it is more expensive.
  3. After      purchasing the filter, make sure you have your eye protection, gloves,      ratchet, socket and screwdriver before beginning the procedure.
  4. Remove the  glove compartment. Usually, vehicles are equipped with bolts and screws to  hold the glove compartment in. Your glove compartment may have tabs as  well, so be careful when removing the compartment and use the tabs to  remove.
  5. After removing the bolt and the screws, remove the glove box frame.
  6. Locate the filter housing. Look for a removable plastic filter cover.
  7. Remove the filter. Most under-dash filters can be removed simply by opening the      filter door.
  8. Before installing the new filter, vacuum the filter chamber to remove any excess      particles. You may also take a damp cloth and wipe the inside of the air      filter chamber to clean out unwanted dust and particles.


  • If you park next to trees, consider waiting to change the cabin air filter until the trees are done pollinating for the season as the pollen can find its way into the filter.
  • People who suffer from allergies may consider changing the cabin air filter more often.
  • Be careful squeezing the tabs, they break easily, so don’t overdo it.

In order to help keep your car’s ventilation system running at optimal efficiency (as well as protect the health of yourself and your passengers), it’s important that you replace your cabin air filter on a regular basis. The money you spend on a replacement filter and the time you spend installing it are well worth the benefits to your car and your health.

This post was written by: Martin Hand


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About Martin Hand

ASE Certified L1 Advanced Mastertech. Martin Hand has over 15 years experience in Asian and European Import Auto Repair. Specializing in electrical diagnosis, engine performance, AT/MT transmission repair/rebuild. Martin is also pursuing a degree in Computers Science & Information Systems starting at Portland Community College while he plans to transfer to OIT. Certified in Java application level programming, experienced with other languages such as PHP, Ruby, JavaScript and Swift. Martin has future plans of automotive diagnostic software development.


  • For a car’s engine to run efficiently, it needs air – CLEAN air that will be mixed with the fuel. So inferring from its name, it really doesn’t take a genius to know that the air filter is responsible for keeping the dirty stuff (that comes with the air) from getting into the engine.

  • Jackob says:

    Maintenance is important. Everything require time to time. Air filter also need to clean with time. Remove dirt from it.

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