Quote Originally Posted by Alan Lightstone View Post
Interestingly, I happened to watch an episode of Ask This Old House. In it, they built a fan enclosure with four 20"x20"x2" MERV 13 filters and placed it over a 20" fan. Their enclosure consisted of duct taping the filters together with cardboard on the bottom. So an even cheaper method, but certainly not a durable one.

https://www.thisoldhouse.com/green-h...diy-air-filter
Ask This Old House DIY Air Filtration.jpg

I actually may build one of these for kicks and place it next to my wide belt sander. If I do, I'll definitely post the air quality results vs time. I can place it on top of the Felder jointer. It's the typical horizontal spot where I put junk. I'll have to remove the crap. Not a bad idea anyway.
I can't see why those wouldn't be effective for you to some extent, or maybe more. The TOH "build" (term used begrudgingly lol) is basically the same thing as my cart.

I used the cart yesterday sanding/shaping Walnut with a host of machines and sandpaper. At one point I had the wrong blast open while using the oss.....looked over at the Dylos and PM 2.5 was at 990. I cranked the cart from low w/ speed control knob at low to high with speed control to high. After approx 2-3 minutes the PM was under 200. I hate the smell of walnut being cut so that's how I knew the wrong gate was open.