The Ultimate Air Purifier Test

We put several of the leading brand air purifiers to the test – a real-world test.  Why?  To find out which air purifier is best at cleaning a room.

Choosing an air purifier is confusing.  Terms like "True HEPA", "kills 99.9%" and "destroys pollutants" are misleading.


Scroll down for test results and videos


The goal of this test is to see how well different air purifiers clean a real room.  Not a gimmicky little smoke box, but a full-sized furnished room that humans can actually live in and want to keep clean.


We take an air-sealed room, fill it with a consistent amount of smoke, and time how long it takes for the air purifier to clean the room to a healthy level according to EPA standards.  The air quality is measured by the PM2.5 meter in the room, located where a person would be at the desk.  The screen is enlarged on the top left corner of the videos.




These are the time-lapse videos showing how each air purifier we tested cleans the room.

Elemental Air Systems | Aspen

Dyson | Purifier Cool

Molekule | Air

Blueair | Classic 605

Oransi | EJ120

IQ Air | HealthPro Plus

Alen | BreatheSmart 45i

Levoit | LV-H132

Envion | Ionic Pro

Aerus Beyond | Hydroxyl Blaster

Honeywell | QuietClean

Levoit | LV-PUR131S

Test Notes:

  • Every air purifier is tested the same way.
  • The room is furnished because that's how rooms are in the real world.
  • The air quality meter is positioned where a person would actually be breathing in the room.
  • The air purifier is located where it actually would be used in a room.  Each unit is in the same place.
  • All air purifiers have new OEM filters.
  • The smoke is pumped in through a duct system.  All ducts are air-sealed and connected only to the room.
  • The smoke particulates are between 1 and 50 microns.
  • The air quality meter is a laser particle counter that is calibrated and accurate, with a measurement range of 0-999µg/m3.
  • The green lights are to illuminate the smoke in the room so we can see how the air purifier is cleaning the air.
  • The time it takes for the air purifier to clean the room starts when the air purifier is turned on and stops when the PM2.5 concentration drops below 12µg/m3.  This is the "healthy" level according to EPA standards.  There is a 20 minute time cap on the test.  If an air purifier fails to clean the room in 20 minutes, the "score" is the PM2.5 level at the 20 minute time cap.
  • The videos are all consistently sped up to 3x speed for the first 8 seconds, then 30x speed for the remaining time, so we can view the tests in a reasonable amount of time.

What real customers are saying

"This is a game-changer to the air filtration industry. We have one in the office and one at home. People, both employees and visitors to my home, have asked what I have done to make the house/office feel and smell so much better. I just point to the ASPEN."

Jordan W.

"I don't have allergies but when I heard about the Aspen, I thought "who wouldn't want better air to breathe in the home?" I set the machine up one evening. The next morning I could tell a drastic difference in air quality. The air felt crisp which is how I describe it to everyone. I never would have believed it. It feels like the type of air you want to breathe deeply in."

Jerry G.


"I have had severe pollen allergies in the Spring for over ten years. I have tried almost everything receiving little to no relief. We are currently in peak season for pollen and the Aspen has far exceeded my expectations! I CAN FINALLY BREATHE COMFORTABLY and RELAX in my home!"

Samuel L.

"The Aspen air purifier is amazing. My home is new construction and I've been struggling with allergies from VOCs and construction dust. Aspen has made a huge difference in the quality of air in my house, it smells fresher and I can breathe better."

Autumn J.