You're three tabs deep comparing air purifiers, and every product page is throwing the same wall of terms at you: HEPA, CADR, ACH, "medical grade," "hospital grade," ionization, ozone-free. Half of it sounds impressive and none of it tells you which one actually works. Here's what these terms mean in plain language, and which ones are worth paying attention to.
HEPA: the one term that actually has a legal definition
True HEPA means a filter captures at least 99.97% of particles down to 0.3 microns in size. That's not a brand's opinion of itself, it's an actual filtration standard. The catch: some products say "HEPA-type" or "HEPA-like," which sounds nearly identical but has no enforced standard behind it and can mean the filter is meaningfully less effective. If a product doesn't say "True HEPA" specifically, assume it's not.
CADR: the number that matters more than square footage
CADR stands for Clean Air Delivery Rate, and it measures how much filtered air a unit actually pushes out per minute. This is the real performance number. The "covers up to 800 sq ft" claim on the box is a derived estimate built from CADR under ideal lab conditions, an empty room, 8-foot ceilings, no furniture. Two purifiers can claim the same square footage coverage and have very different CADR numbers underneath, which means very different real-world performance. If a brand publishes CADR, that's a good sign. If they only publish square footage with no CADR anywhere, that's worth noticing.
Activated carbon: solves a completely different problem than HEPA
HEPA catches particles, physical stuff like dust, pollen, and mold spores. It does nothing for gases or odors. Activated carbon adsorbs gases and VOCs, like paint fumes or cooking smells, but it doesn't capture particles at all. These aren't competing technologies, they're two separate jobs. A purifier that only has HEPA is leaving gas-phase pollutants untouched. A purifier that only has carbon is leaving particles untouched. If odor and chemical sensitivity matter to you, check that a unit has both.
Ionization: not automatically dangerous, but worth understanding
Ionizers charge airborne particles so they clump together and get captured more easily. The controversy around ionizers isn't about the concept, it's about a specific byproduct: some ionization technologies produce ozone as a side effect, and ozone is a lung irritant, not a purifier. This is where "ozone-free" claims matter, and it's also where you should look past the marketing copy to actual certification.
CARB certification: the difference between a claim and a verified fact
The California Air Resources Board tests ozone output from air-cleaning devices and certifies units that fall under its safety threshold. This is independent, third-party verification, not the manufacturer grading its own homework. When a brand says "ozone-free," ask whether that's CARB-certified or just a description they wrote themselves. Those are very different levels of trustworthy.
"Medical grade" and "hospital grade": phrases with no standard behind them
These terms sound official and mean nothing in particular. There's no regulatory body that certifies a consumer air purifier as "medical grade." It's marketing language, not a specification. If you see it on a product page, look past it for the actual numbers: CADR, filter type, certifications. Those tell you something. The phrase itself tells you nothing.
ACH, or air changes per hour
This describes how many times a purifier can theoretically cycle all the air in a given room within an hour. A higher ACH means faster, more thorough cleaning of that specific space. It's related to CADR but expressed differently, and it's genuinely useful when you're trying to figure out if a unit is powerful enough for a room with a real health concern, like a nursery or a room where someone has asthma, versus a room where general freshening is the goal.
UV-C: a real technology, applied narrowly
UV-C light disrupts the DNA of microorganisms passing through the unit, which matters for viruses and bacteria in a way that particle filtration alone doesn't address. It's a legitimate technology, but it only affects what passes directly through the light's path inside the unit, it's not doing anything to the room at large on its own. Treat it as one layer in a multi-stage system, not a standalone selling point.
How to actually evaluate a brand's claims
Look for CADR numbers, not just square footage. Look for "True HEPA," not "HEPA-type." Look for third-party certification (CARB, AHAM) behind any ozone-free or performance claim, not just the brand's own description of itself. And be skeptical of any term that sounds impressive but has no standard behind it, "medical grade" being the clearest example. A brand that's confident in its actual numbers will show you the numbers instead of leaning on the adjectives.
Where the iAdaptAir's claims come from
The iAdaptAir's HEPA filtration meets the True HEPA standard, capturing particles to 0.3 microns. It's CARB-certified ozone-free, independently verified rather than self-described. The filtration stack combines True HEPA, activated carbon, UV-C, and bipolar ionization, each addressing a different part of the problem rather than one technology doing all the marketing work. The air quality ring gives you a real-time read on what's actually happening in the room: green, orange, or red, based on live sensor data, not a promotional claim.
The best way to tell if a purifier brand is overhyped isn't to read their claims more carefully. It's to see whether they'll show you the numbers behind the claims at all.
Shop Air Oasis and find the iAdaptAir sized for your space. Breathe Better, Live Better.
