How Do Car Air Purifiers Work?

We’ve all heard about the health benefits of fresh and clean air and air purifiers do just that – they improve the air quality. These devices come in many shapes and sizes with a variety of features and nowadays they’re not limited for home use only; you can put one in your car as well.

Car air purifiers are generally smaller and more compact versions of the air purifiers you would use at home, although they usually have a more intuitive interface. They also bring more specialized features designed for better ease of use in the car. But how do they actually work?

The Benefits

When we talk about air pollution, we tend to forget that the cabin of the car is not pollutant-proof. Air circulates in and out of the car and there are certain polluting particles that are generated in the car itself. So, taking care of air quality in your car is rather important. But, before we get into the nitty-gritty mechanical side of things and the types of car air purifiers out there, it’s important to ascertain the health and wellness benefits of using a car air purifier in the first place.

  • Reducing airborne allergens
  • Lowering blood pressure
  • Stress relief
  • Removing bacterial and viral particles
  • Preventing diseases stemming from air pollution

Car Air Purifier Types

Car air purifiers come in many different forms, employ different technologies, and have a plethora of different features. But, almost all of them use the main three technologies in one combination or the other – HEPA filters, ionization, and ozone generation.

HEPA Filters

High-efficiency particulate air filters, or HEPA, are the standard for efficiency in air filtration. Initially commercialized in the distant 1950s, the original term has by now become a generic term for highly efficient filters using deeply layered filtering technology.

Although the technology is far from new, that doesn’t take away from its air purification capacity. As such, the car air purifiers that use a HEPA filter are usually the ones that provide the most bang for your buck when it comes to keeping the air fresh and clean. You can read more about which car air purifiers are the best at utilizing this technology in our Best Car Air Purifier Reviews & Buying Guide.

The make-up of the filter is mainly fiberglass, but each car air purifier adds its own twist, be it for even better efficiency or odor removal. The way that these purifiers function is that they force the air through the filter, which traps all the unwanted particles, leaving you with clean air that comes out on the other side.

If you’d like to read more about filter replacement check out Everything You Need to Know About Air Purifier Filter Replacement.


Air ionizers release negatively charged ions, i.e. particles with extra electrons. This technology is much more recent in comparison to the HEPA filter. The car air purifiers that use this technology purify the air by releasing a lot of these particles and they stick to positively charged particles which are mostly the harmful ones. As a result, they make the harmful germs and bacteria heavier, up to a point where they can’t stay airborne and enter your lungs. This is exactly what made them grab public attention in East Asia during the SARS epidemic. In light of recent events, it makes you wonder whether they’ll become even more popular.

But nevertheless, ionizers are equally great for eliminating bacteria and germs and unwanted odors and harmful gases.


In other than commercial grade ozone-generating devices, which should not be used in the small confines of an occupied car under any circumstances, the ozone generation technology has little to no effect by itself when it comes to air purification. That being said, some car air purifiers combine this technology with other effective purification methods to provide better odor removal.

The ozone molecule is very good at neutralizing unwanted odors and as such, it is generated in safe amounts by certain car air purifiers. Consumer-grade ozone-generating devices are largely ineffective when it comes to eliminating harmful air particles. That’s why some car air purifiers have ozone generation as an additional feature, rather than having it as a main air purification method.


Now that you know the inner workings of a car air purifier, you can know what to look for when choosing one. To summarize, none of the car air purifiers use a single technique and they usually use some combination of the aforementioned three technologies. There are different subtypes of them as well, especially with HEPA filters, but these are their main functionalities.

We hope that we answered all of your questions and should you have more, head over to Best Car Air Purifier Reviews & Buying Guide.