{"id":3961,"date":"2026-03-09T11:04:30","date_gmt":"2026-03-09T03:04:30","guid":{"rendered":"http:\/\/smartairfilters.com\/?p=3961"},"modified":"2026-03-09T11:04:31","modified_gmt":"2026-03-09T03:04:31","slug":"xiaomi-purifier-auto-mode-leaves-air-unsafe-86-hours","status":"publish","type":"post","link":"https:\/\/smartairfilters.com\/en\/blog\/xiaomi-purifier-auto-mode-leaves-air-unsafe-86-hours\/","title":{"rendered":"Xiaomi Mi 2 Air Purifier Review: Auto Mode Leaves Air Unsafe"},"content":{"rendered":"

Review Xiaomi Mi 2 air purifier – a good cheap and effective air purifier?<\/h3>\n\n\n\n

Ever since I coughed through a Beijing airpocalypse, I\u2019ve been saying clean air doesn\u2019t need to cost an arm and a leg. I even set up Smart Air<\/a> to provide low-cost purifiers to people around the world based on that data.<\/p>\n\n\n\n

So when the Xiaomi 2 air purifier came out for under $150 (10,000INR \/ 1,000RMB), I assumed it worked just fine. But I had never gotten around to testing it\u2014until now. And what I found testing the Xiaomi Mi 2 shocked me.<\/p>\n\n\n\n

Xiaomi Mi 2 Air Purifier: Put To the Test<\/h2>\n\n\n\n

Smart Air co-founder Anna ran a brand new Xiaomi Mi 2 air purifier in the 15m2<\/sup> Smart Air test bedroom where we\u2019ve tested the DIYs, IQ Air, Blue Air, and Philips<\/a>. Anna ran six tests on auto mode and six tests on the highest setting (which the Xiaomi 2 air purifier oddly calls “Favorite mode”).<\/p>\n\n\n

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\"Xiaomi<\/figure><\/div>\n\n\n

Anna turned the purifier on in the morning when she left home and turned it off when she returned home. That means there was no one in the home during the tests. The doors and windows were closed during the tests. (More details on the test method and all original data are here<\/a>.)<\/p>\n\n\n\n

A Dylos Pro tracked \u2265 0.5 micron and \u2265 2.5 micron particle counts during the test. Test data shows these 0.5-micron readings correlate highly with the US Embassy\u2019s PM2.5 readings<\/a> \u00a0(r <\/em>= .90).<\/p>\n\n\n\n

As in my earlier tests<\/a>, I calculated effectiveness as (the number of particles before turning the purifier on) versus (the average number of particles over the last four hours).<\/p>\n\n\n\n

Xiaomi Air Purifier 2 Test Results<\/h3>\n\n\n\n

The Xiaomi purifier scored as one of the worst purifiers I\u2019ve ever reviewed. On average, it removed only about 60% of 0.5-micron particles over the last 4 hours of the test.<\/p>\n\n\n

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\"Xiaomi<\/figure><\/div>\n\n\n

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And oddly enough, the auto mode and the high mode results of the Mi 2 purifier were nearly identical. That’s a mystery.<\/p>\n\n\n\n

Here\u2019s how the Xiaomi results compare to earlier results from other purifiers<\/a> using the same method, the same particle counter, in the same room.<\/p>\n\n\n

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\"Review<\/figure><\/div>\n\n\n

The data shows the Xiaomi air purifier performed worse than the $30 DIY purifier<\/a> I’ve been showing people how to make for years!<\/p>\n\n\n\n

Below is a normal test day. I put a dashed red line representing the World Health Organization\u2019s 24-hour PM2.5 limit (25 micrograms)<\/a>.<\/p>\n\n\n

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\"Xiaomi<\/figure><\/div>\n\n\n

The Mi Air Purifier Really Wants To Be in Auto Mode<\/h3>\n\n\n\n

What\u2019s wrong? The key is that\u2014even on the highest setting\u2014the Xiaomi reverts back to auto mode after 3 hours.<\/p>\n\n\n\n

WATCH: Xiaomi Reverts to Auto Mode After 3 Hours<\/h3>\n\n\n
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Xiaomi 2 Air Purifier Auto Mode Issue & Fix<\/div><\/div>
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