What Do Air Purifiers Do and How Do They Work?

Recently I discovered thousands of people ask Google “What do air purifiers do?” and “How do air purifiers work?” each month. Ten years ago, Smart Air’s founder and University of Chicago Professor Thomas Talhelm had these questions too. In fact, these questions ultimately led Thomas to create Smart Air and bring transparency to the air purifier industry.

Let’s take a closer look at what air purifiers do and how they work.

What Do Air Purifiers Do?

There are a lot of devices for sale marketed as “air purifiers” and unfortunately many of these “air purifiers” don’t actually clean the air very well. Let’s first break down what an effective air purifier does and how it works (it is incredibly simple!).

What an Air Purifier Removes From Your Air

A HEPA air purifier removes over 99.97% of all dangerous air particles, including:

Allergens including pet dander, pollen, and mites (reduces allergy symptoms)
PM2.5 (tiny cancer-causing particles)
Dust
Mold
Viruses (removes COVID-19 and reduces spread)
Bacteria

In addition, some air purifiers include an additional carbon filter that can remove gases and smells such as:

Formaldehyde and other cancer-causing VOCs
Cigarette smoke
Smoke smell and other bad smells

How Do Air Purifiers Work? Incredibly Simple.

The most effective air purifiers work extremely simply: a fan and a HEPA filter. The fan pushes air through the filter where unwanted pollutants and irritants are removed. HEPA filters are the gold standard of filtration. HEPA filters filter out nearly all (~99.97%) of pollutants (allergens, PM2.5, bacteria, viruses) in the air on the first pass through the purifier.

Dirty HEPA air filter in Mongolia — A used HEPA filter filled with dirty, cancerous particles after months of use.

An effective air purifier is really that simple. Professor Thomas Talhelm discovered this a decade ago after seeing how expensive air purifiers were and asking the same question: “How do air purifiers work?”.

After tearing apart some air purifiers and researching how air purifiers worked, he realized air purifiers do not need to be expensive. Thomas started selling simple DIY air purifiers by attaching a filter and a basic fan that outperformed $1,000 purifiers.

WATCH: Smart Air Founder Thomas Talhelm showing the magic of a simple DIY purifier

Why Use Air Purifiers?

According to the WHO, 99% of the world breathes unhealthy air. Unfortunately, most of the time you can not tell you are breathing toxic, cancer-causing air. Every home has some levels of dangerous PM2.5 particles, and the right air purifiers can remove nearly all of it from your air.

Reducing the PM2.5 you breathe can reduce your risk of death from air pollution significantly. Even reducing air pollution at low levels can reduce fatality significantly.

In addition to reducing your risk of death, HEPA air purifiers have many other science-backed benefits. HEPA filters significantly reduce COVID spread, lower blood pressure, reduce allergy symptoms, and even reduce inflammation throughout the body in the first 48 hours.

Take Caution

Although an extremely effective air purifier is super simple and inexpensive, many air purifier companies will hide this truth so they can rip you off and convince you to pay for some ineffective (and often dangerous) “fancy” technology.

When buying an air purifier, avoid those with extra add-ons such as UV lights and ionizers. These add-ons not only increase costs but can be dangerous to your health. For example, ionizers have been shown to actually increase dangerous air pollutants such as PM2.5 and formaldehyde significantly.

Unfortunately many of the top air purifier brands such as Blueair, Xiaomi, Medify Air, and more use ionizers. As a social enterprise tasked with helping people breathe safely at an affordable price, Smart Air pledges to never use ionizers in any of its air purifiers.

Guide to Choosing the Best Air Purifier

Figuring out what air purifier to buy and which is the best can be difficult. At Smart Air, we created a simple 4-step guide to help you find the best air purifier for your space.

What is an air purifier and how do air purifiers work?

The best air purifers are simple: fan + HEPA filter. HEPA air purifiers can remove 99.97% of viruses, allergens, PM2.5, dust, and bacteria from your air. Unfortunately, many air purifiers sold on the market use dangerous gimmicks that can actually make your air worse.

Smart Air