Improve Air Quality, HVAC Performance and More: A Guide to Your Car’s Cabin Air Filter

The Bureau of Transportation reports that, on average, U.S. households today have more cars than drivers. Still, most drivers don’t remember the last time they replaced their air filter. While frequently neglected, a cabin air filter can impact your HVAC’s performance and your health. Whether you’re experiencing foul car smell or allergies, a dirty cabin air filter could be the source of the problem.

Your car has four filters: one for oil, one for fuel, and two types of air filters—one that filters the air going into the engine and another that cleans the air entering the cabin. As air enters your car’s interior through the HVAC system, your cabin air filter traps pollutants, debris, and contaminants before they enter the cabin. Without a functioning air filter, you could breathe in harmful emissions and contaminants, triggering allergies and other respiratory reactions. 

Cabin filters vary in degrees of protection, but standard filters effectively trap most pollutants. According to the Environmental Protection Agency, a High-Efficiency Particulate Air (HEPA) filter can remove 99.97% of contaminants with a size of 0.3 microns, making it effective against smoke and bacteria. Coronavirus particles range from 0.6 to 0.14 microns in size, creating challenges for cabin air filters. But hope isn’t lost. The Car Guide reports that Honda recently announced that they’ve developed a new filter built to deter the spread of the virus. But there have been no recent updates about when the filter will be available in the U.S.

While your car may alert you when it’s time to change the oil or when a tire’s air pressure is low, air filter maintenance can be easily overlooked. But replacing your cabin air filter on schedule is just as important, and here are a few signs that it may be time:

Some cabin air filters are reusable, but most manufacturers recommend replacing your air filter every 15,000–30,000 miles. Your environment, type of filter, make and model of car, and how much you drive all determine how often your cabin air filter needs to be replaced. If you have long daily commutes or live in an urban area with high traffic, you may have to replace your filter more frequently. Other factors like smoking tobacco or the use of hair spray products in the car can clog your filter and require earlier replacement. Consult your car manual for specific vehicle guidelines. 

The cost of a cabin air filter varies, but the average cost is between $15 and $50. But be prepared to pay for labor or fees when having one professionally installed.

The great news is the filter is often easy to change and can be a quick DIY project for most car owners. You can typically find the filter behind the glove box, and the process should only require a few tools. Be sure to clean out any debris around the filter and vacuum the area before attaching the replacement. Your owner’s manual will be able to provide step-by-step directions.