Ok, like you, I was pretty sceptical, even with smartfilters doing the laser particle counter testing.
Check out the smoke clearing video here in this taobao listing as well as constant drop on the Dylos Laser Particle Counter. IT's youku, so I cannot embed
hepa
And also this
Particle Counting - Finally! Directly comparable tests: DIY versus Blue Air
1. Is the air coming out of the purifier clean? This is the easier question to answer, and my tests are as clear as can be. The DIY purifier shoots out very clean air.
2. But is that enough to actually clean the ambient room air? For example, if you have a really tiny filter and a huge room, the filter could work properly but still not be strong enough to make a difference.
Answering this question is more difficult because you need a controlled environment (you can’t open and close windows during the test), and you need to test the air for a longer period of time. Fortunately for you, I’m a nerd, and I’ve been doing these tests for fun for the past few weeks.
RAW Data for the box fan in the 15 sqm room. Biggest drop is in 1hr mark, continues to slowly drop till 2nd and 3rd hour.