How do air purifiers work?

How do air purifiers work?

Learn more about the different air purifier technologies on the market – and their pros and cons – to make an educated purchase.

You clean your home regularly, wiping down counters and vacuuming the floors you walk on, but what about the air you breathe? Although invisible, contaminants can build up from pets, pollen, dust and cooking – along with harmful volatile organic compounds (VOCs) from things like carpets, cleansers and paint – and contribute to indoor air that is often more polluted than outdoors. That’s where air purifiers come in, helping to remove pollutants, which is just as important to well-being as a clean space. But not all air purifiers work the same way, and it’s worth understanding the differences in technology so you can make the choice that’s right for you.


HEPA, or high-efficiency particulate air, technology is reliant on special filters: A fan sucks in particles through a filter (often made of fiberglass) with millions of tiny gaps. Larger gaps trap dust and pollen, while ultra-fine ones help catch tiny contaminants as small as 0.1 microns. After passing through the filter, cleaner air is pumped back into your living space. For any air purifier to be labelled HEPA, it must remove at least 99.97 percent of particles with a diameter of 0.3 microns, with even better efficiency for larger particles. It’s a very efficient form of air purification, but the major downside to HEPA machines is the ongoing maintenance and cost: Filters need to be replaced regularly to maintain performance.

UV light

This air purifier technology uses short-wave ultraviolet light (UV-C light) to neutralize harmful air particles such as pathogens, mold and bacteria. When air is drawn into the device, it passes a UV lamp, which cleans the air throughultraviolet germicidal irradiation (UVGI). It’s a common method of disinfection (especially in food production plants and hospitals), but the concern with UV-C air purifiers is that most on the market can’t trap or remove particles.

Carbon filters

Carbon filtering relies on a layer of activated carbon which absorbs organic compounds and pollutants. Charcoal filters are usually an add-on to HEPA purifiers or air conditioning units since they’re effective at getting rid of smoke, chemical fumes and other odors in the air. They fall short in the fact that they can’t remove micro-organisms (the smallest particles they tackle are 0.5 microns), nor allergens like dust or pollen.


This type of air purifier gives a negative electrical charge to molecules in the air. These charged molecules, known as ions, react with pollutants and particles and cause them to stick to surfaces (like walls, furniture and floors) instead of lingering in the air. The obvious issue with this technology is that you still end up with harmful particles in your living spaces (unless the purifier has a positive charging plate to attract the negatively charged ions and pollutants). Even if so, there are doubts about the efficiency of ionizer air purifiers – one study showed that most ionizers are too weak to even efficiently remove particles from air in a medium-sized room.


Ozone generators of the past became notorious for generating unsafe amounts of ozone, or O3, which can inflame the respiratory systems of humans and animals. OZONOS air purifiers are very different. Safe and certified by Health Canada, they use a patented technology that releases only a trace amount of ozone that’s completely harmless to pets and humans (the AC-1 produces less than .05 parts per million – lower than the amount in fresh outdoor air after a thunderstorm). In each OZONOS air purifier, the UV-C light also helps destroy germs, bacteria, viruses and mold spores. The end result is healthier air that’s cleaned quickly and efficiently without the need for costly filter changes (the UV-C bulb is the only part that requires replacement, and only after about 2 years or 8,000 hours).

How do I know if the air purifier is working?

You should notice a significant decrease in odor levels when cooking or in rooms that would otherwise smell like pets or fumes. To make sure your air purifier is working efficiently, try to position it on a raised surface, such as on a shelf or a piece of furniture, since warm air rises – and with it, aerosols.

Air quality monitors such as Kaiterra can track levels of PM2.5 (fine dust or particulate matter), VOCs, CO2, temperature and humidity. They provide quick, up-to-date and accurate reports of air pollution via an app, so you can gauge how well your air purifier is performing.

Still have questions about how OZONOS air purifiers work or need help choosing the best model for your needs? Contact us and we’ll be happy to help.