DIY air purefier and some interesting charts

I tripped over this on Reddit in r/WoodWorking and thought to share.

I was hoping BobL might have a word to say if he finds time.

The dude made a DIY dusty to simply clear the air and was curious about a few aspects of commercial machines and a fan-bungy-MERV13-filter Frankenstein.

Turns out to be a VERY interesting question!

Made a mobile air filter for the shop using 8 MERV-13 filters, a 70-micron mosquito mesh, and a Dewalt shop fan. Certainly won't win any beauty awards, but it works rather well : woodworking

and see here: Experiments on a $50 DIY air purifier you can make in 30s

Attachment 505447 Attachment 505448

Some other threads here on the same subject:

Improvised Ambient Air Filter
Air purifier using a box fan
researching room air filter - Corsi-Rosenthal box- replacin Merv 13- MPR 1800 or 1900

Two downsides about using an axial fan are;

They'll move a lot of air when the filters are clean but much less when the filters clog up. So either be prepared to clean filters often OR use something like a centrifugal fan. I'd like to see the same graph after say 25 hours of use.

Axial fans make a lot of noise - I wouldn't want one running for many minutes in my workshop.

I serious doubt we could get the same parts here in Oz for US$50, I'd expect something like AUD$150

Capture the dust at the machine because catching it after it is in the air is admitting your DE system is not up to the task. Once it is in the air you start to breathe it in and I thought that avoiding breathing dust was the goal of dust extraction.