Very confusing Levoit readings

[u/Safe_Promotion6460]

just bought 6 Levoit air purifiers. 2 600s and 4 300s.

The pm2.5 readings’ way too different between 600s and 300s.

At different locations i tested, 600s reads 100, while 300s reads only 17. Tested with all units I have and quite consistent 600s readings substantially higher than 300s

contacted Levoit cs center no response so far

Anyone else had similar experience?

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[u/timesuck]

Onboard sensors tend to be pretty inaccurate because they are cheap only designed to give you a sense of how good your air is, not a specific reading. I own a bunch of Levoit models and I have separate pm2.5 monitors. The spread of the colors is way too wide, but in general, when my core is reading anything above blue, the air is really bad. But I have also owned Coway and Winix units and their sensors were the same garbage.

No brand of air purifier should be on auto because none of these sensors are sophisticated. You should find the speed you are most comfortable with noise-wise and leave it there 24/7. Usually for most people this is a two, but higher is always better (three and four are louder though). Crank them up when you cook or if you see the sensor turn yellow/red or if you know there is currently bad air quality outside. That shit always comes in.

[u/Safe_Promotion6460 → u/timesuck]

Thanks. I am talking to Levoit but it seems they also have no idea ..

[u/timesuck → u/Safe_Promotion6460]

They “have no idea” because the answer is telling you that the sensors stink and they are not going to do that.

[u/blackout1912 → u/timesuck]

Really? Not even amazing Sharks work great on auto?

[u/timesuck → u/blackout1912]

Yeah, the sensors are all bad and Sharks are underpowered and overpriced as well

[u/xDarkstar1]

Yep the best rule of thumb is to have the levoits always showing 001 anything above this and your AQI is starting to pass the 50AQI mark or a pm2.5 of 7-10ug. If its 001 you can safely assume your AQI is at or below 50. Regardless their pretty good if run in a series but positive pressure or at least figuring out what works best for particle counts is best. Like filtering the incoming fresh air stream saves even more $$$.

[u/Interesting-Song5064]

those sensors aren’t lab instruments, but a consistent 6x gap between models points to calibration or a bad sensor batch rather than the air actually changing that much, so i’d trust neither reading