35 healthy Shanghai college students used a purifier for 48 hours. Here’s what happened to their bodies

There are two things we know about purifiers and one really important thing we don’t know.   1. We know that purifiers reduce PM2.5   Loads of tests have found this in labs and in real-world homes. I’ve tested the hell out of this, in my room, in bigger rooms, for 200 days of Beijing air, comparison tests against the […]

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Plants Have No Detectable Air Purification Effect

Despite the popular conception that plants are purifiers, plants have detectable effect on particle or gas pollutants, according to the latest test data from real-world homes.   Belief that plants are effective air purifiers is widespread. Arguably the most frequently cited evidence is the NASA study on plants. It feels scientific, authoritative. This page cites it, this page, this page.   […]

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This Data Explains Why You Should Never Use Your Purifier’s Auto Mode – Supplemental Data

Data and Test Details   Test Methods: These tests were identical to my previously published tests, details of which can befound here, here, and here. Original Data: The original data for all 13 tests is available as an Excel file here   Average Outdoor PM2.5 During Tests It’s important to note the average outdoor PM2.5 during tests because purifiers achieve smaller percentage […]

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