Can I Put a HEPA Filter in My Car?

There’s a severe air pollution problem globally, and it’s like nowhere is safe from this hazard. Unfortunately, clean air almost seems like a luxury from your home to your office and even your car. Thankfully, many new cars have a cabin filter to tackle this issue, but can you put a HEPA filter in your vehicle?

You can put a HEPA filter in your car, as long as you use it as a cabin air filter. You’d need to change your cabin filter at some point, and a HEPA filter is an excellent replacement option. A portable car purifier that uses HEPA filters also works.

This article delves into cars with a HEPA filter and if you can put a HEPA filter in your vehicle. I also review the option between HEPA and regular cabin filters.

What Cars Have a HEPA Filter?

It wasn’t until the late 1980s that car manufacturers started adding cabin filters to cars. Today, over 90% of new vehicles and trucks have cabin air filters. Surprisingly, a marginal number of drivers know about it, and the few who do might not be maintaining it well.

Premium car models usually have cabin air filters as standard equipment. Other cars make them part of an option package or a stand-alone option. There are also luxury cars with two or more cabin air filters, and even electric vehicles have them.

The increase in the availability of built-in vehicle air filters emphasizes the importance of air quality, even in cars. Of course, different car models will use filters of different standards and designs.

HEPA (high-efficiency particulate air) filters are known as the best filters for particulate matter, and some cars use them as their cabin air filters. Here are the vehicles that have a HEPA filter:

  • Tesla models S, X, and some Ys in China offer HEPA air filtration.
  • The Hyundai Creta
  • The Kia Seltos
  • The 2022 Mercedes EQS from Mercedes-EQ

In 2016, Tesla introduced the HEPA filter and Bioweapon Defense Mode or the Biodefense HEPA filtration system in Models S and X. Today’s Tesla models S, X, and Y have them as standard features.

Tesla overcame the HEPA filter-HVAC issue by building fans strong enough to power through the filter’s airflow resistance. Tesla’s HEPA filtration system is activated whenever the vehicle’s climate control pulls air from outside. You can use Bioweapon Defense Mode in extreme conditions to prevent pollutants from entering the car.

The Bioweapon Defense Mode pressurizes the cabin upon activation. As a result, all the air entering the cabin in this mode passes through the gas media and HEPA filters.

The 2022 Mercedes EQS HEPA filter has the “OFI Quality Seal ZG 250-12” in the area of bacteria and viruses. The filter uses the space under the car’s front bonnet and is part of the optional equipment ENERGIZING AIR CONTROL PLUS.

Can I Put a HEPA Filter in My Car?

Maintaining clean air in your vehicle’s cabin is quite challenging for several reasons, including the different contaminant sources. You also have limited ways to remove the contaminants, and pollutant levels are higher than what you’d typically face at home. 

This means many of the usual air cleaning methods you use at home won’t work for a car’s unique conditions. Fortunately, your car’s built-in air filter can remove particulate contaminants from the air excellently. 

A car’s cabin air filter varies by design, and the types and sizes of contaminants it can trap follow these variations. However, all cabin filters usually capture these contaminants:

  • Dust and dirt
  • Leaves and twigs
  • Smog and soot
  • Mold and other spores
  • Bacteria
  • Rodent droppings
  • Mildew
  • Fungi

If you can think of any undesirable debris, a cabin filter can probably trap it. 

Although it efficiently removes some fine pollutant particles, your regular cabin filter can’t handle the tiniest particles. HEPA filters are more efficient, and you can use them in place of the standard cabin filters. A HEPA filter can remove 99.97% of 0.3 micron-sized particles or larger.

Two precautions to take concerning the use of HEPA filters in vehicles are:

  1. Airflow restriction: Some HEPA filters have multiple layers for a more thorough filtration process. However, the fineness of the filter media can restrict airflow to the HVAC system of your car. This makes the system work harder to circulate air, and it can cause mechanical damage to the system.
  1. Engine filter: Never use a HEPA filter to replace your car’s engine filter. It is grossly unsuitable for your engine’s air needs and can impede its performance.

If your vehicle doesn’t have an in-built cabin filter, you can still enjoy the benefits of a HEPA filter. Many portable car air purifiers use HEPA filters. You should check your state’s laws about their use, though, because some states have bans in place concerning them (e.g., California).

Types of Pollution in a Car

There are two major sources of pollutants in a vehicle: pollutants created inside the car and those entering the car from outside. The car’s occupants or the car’s components themselves contribute to creating pollution in it. I have explained the different pollutant sources below:

Traffic Pollution

It comprises particles and gasses, both of which are toxic to your health. Road dust particles can be as tiny as 0.05 microns and come from the roadside, breaks, and tires. These fine particles (often called PM2.5) are some of the most significant contributors to traffic pollution worldwide. 

Pollen may be a large particle, but it causes as much distress as tiny dust particles. You also face harmful gasses like smog and volatile organic compounds (VOCs), including xylenes, benzene, and toluene. Of course, you cannot forget carbon monoxide, nitrous oxide, and ozone pollution.

If you open the window to let in outside air, it won’t work in this scenario because highway traffic produces too much pollution. The best solution is to keep your windows closed and run the vent on recirculation. According to a study, running your car’s vent in recirculation mode can remove about 85% of particulate pollutants from the cabin.

Pollution within the Car

There are so many car components that generate pollutants. The seats, plastic materials in the dashboard, and carpet emit VOCs like toluene, formaldehyde, acetone, etc. UFPs (ultrafine particulate pollutants) from the wear of your car’s brakes or tires also enter the cabin via the ventilation system or windows.

A car at rest also releases some VOCs from the seepage and evaporation of gasoline, hydraulic, radiator, or transmission fluids. Again, you cannot open the windows to let the contaminant build-up out of the cabin, unless you’re on a traffic-free road.

Pollution from the Car’s Occupants 

It includes smells from food or garbage, mold from wet upholstery, pet dander, and tobacco or weed smoke. Eliminating the source is the best way to handle these pollutants. You can clean your car often and thoroughly and avoid smoking inside.

Are HEPA Cabin Filters Better than Regular Cabin Filters?

Any filter might be better than no filter, but the best filter is what you need. Your standard cabin air filter excellently captures particulates in the five-to-100-micron range. However, its efficiency is often about 98%. 

On the other hand, HEPA filters can trap particles of 0.3 microns or larger at an efficiency of 99.97%. That 1.97% is all it takes to make HEPA filters the ultimate standard against airborne pollutants.

One advantage cabin filters have over HEPA filters is their treatment with activated carbon. Many cabin filters have a gray appearance because of their chemical treatment with activated carbon. Activated carbon can remove various odors, including exhaust gas smells like nitrous oxide, sulfur dioxide, ammonia, hydrogen sulfide, etc.

Some of these cabin filters also augment the activated carbon with baking soda to widen the odor range it handles. This more comprehensive range covers odors from mildew, the human body and wet dogs. Although these treated cabin filters can remove some VOCs from your car, the chemical treatment is too small to remove a significant amount.

Before changing your cabin air filter, here are some key features to note:

Protective Ability

Check the protection level the filter offers and only select it if it meets your requirements. A particle filter is suitable for keeping allergens away. However, you’d need a filter with activated carbon fortification if you want to combat foul odors from your vehicle.

Compatibility

Some carbon filter brands claim to produce universal fits, but each vehicle’s HVAC system has a unique size. Therefore, you should ensure that a filter is compatible with your vehicle: model, make, and year.

Longevity

A cabin filter’s average lifespan is about 12,000 miles or one year. However, you can get filters that last for longer, even up to 30,000 miles. There are also reusable filters you can wash, and they are more economical than those you have to replace.

Air filters aren’t created equal, and the disparity is evident in their costs. HEPA filters with a smaller micron rating do better at trapping pollutants than standard filters, so they’ll cost more. A basic cabin filter costs $15 to $50 (excluding labor costs) based on the car model.

Regardless, enjoying cleaner quality air is crucial for your well-being everywhere you go. So, change your cabin air filter as suggested by your manufacturer and limit your contribution to pollution within your vehicle. Lastly, upgrade your cabin air filter to a HEPA filter or a standard filter with carbon treatment for the best filtration system.