I recently built a laminar flow cabinet for seed flasking and I thought I would share some pictures and info on its construction. I just used it for the first time today and it seemed to work great! Long story short, I took a clean room filter (from a photography lab I think) and built a coroplast box around it with a plexiglass front. I also added a pair of furnace filters at the intake vents to block any larger stuff from getting into the more expensive filter.
I forgot to mention that there is an led light on the inside so that you can see what is going on in there as well.
---------- Post added 02-14-2020 at 12:00 AM ---------- Previous post was 02-13-2020 at 11:58 PM ----------
The biggest issue I have found with it so far is that plastic is very prone to static electricity, resulting in every little piece of dust (and in this case hay) in the area sticking to it. To help with this I wipe it down as often as I can with Alchohol (to remove and sterilize dust) and periodically sterilize the entire room with ozone gas.