These days, air quality has once again become a central topic — and one of the major public health concerns. It’s a shame how quickly we forget about this problem as soon as warmer days arrive, but today I won’t dwell on that seasonal amnesia. What’s been occupying my thoughts lately is how we can protect ourselves right now, while thick smog makes every breath feel heavy and long-term decarbonization measures and the transition to cleaner energy sources are still waiting to show tangible results.
You’ve surely noticed that more and more homes now have air purifiers. Perhaps one is quietly humming in your own living room at this very moment, releasing air that seems cleaner than what we see outside (and yes — these days, we really can see the air around us). But is that feeling of cleaner air just an illusion, or real relief for our lungs? It turns out the truth lies somewhere in between.
When I started researching how effective air purifiers actually are, I quickly realized that everything comes down to one essential element: the quality of filtration. And that inevitably leads to HEPA filters, which have become a synonym for reliable air cleaning.
HEPA filters are made from a dense network of fibers that capture 99.97 percent of particles as small as 0.3 microns — the most persistent and penetrating ones, those capable of traveling deep into the lungs and bloodstream. What’s particularly interesting is that HEPA technology wasn’t originally designed for home use. It was developed in the 1940s to protect against radioactive particles, and only later made its way into households, becoming the “gold standard” in air purification, as the IQAir website explains.
Over time, advanced versions emerged as well — such as HyperHEPA filters, which capture ultrafine particles down to 0.003 microns, one hundred times smaller than PM0.3. This means they can remove what was once considered nearly impossible to trap: viruses, nanoparticles, and the finest combustion residues.
However, even the best filter doesn’t mean much if the air simply bypasses it. Many purifiers suffer from poor sealing, allowing air to slip around the filter and carry pollutants back into the room. Devices that solve this issue with airtight housings perform noticeably better in real-world conditions.
Another important thing to understand is that HEPA filters remove particles — but not everything we perceive as “air quality.” They don’t eliminate gases, odors, VOCs, smoke, or chemical fumes. For that, you need activated carbon — and not just a thin decorative layer, but a substantial amount capable of genuinely absorbing irritating molecules.
What I would personally avoid are devices that promise “miracle solutions” — ions, ozone, magical UV lights. Ionizers mostly just force particles to stick to surfaces instead of removing them. Ozone is directly harmful to the lungs, and its presence in certain “cleaner-air” devices remains questionable. UV light in small home appliances simply doesn’t have enough exposure time to effectively neutralize anything moving through the airflow, and it doesn’t remove particles — which are our main issue to begin with.
So what does actually work? A high-quality HEPA or HyperHEPA filter, proper airtight sealing, plenty of activated carbon, and clear, independently verified performance tests. No ozone, no gimmicks, no promises that sound like ads for magic potions.
It turns out that once we understand the basics, choosing an air purifier is no longer a gamble. We don’t need to be experts — just informed enough to distinguish real technology from marketing. That’s when we begin choosing devices that truly protect our health, not just our feeling that we’re doing something good.
Milena Maglovski
