Our shop made air cleaner.
Features include two 20 x 20 prefilters, an internal plenum leading
to a 25x25x18 pocket filter, and a three speed furnace blower with
a timer control. Just pull the string and it'll run for 0.5 to six hours.
It moves so much air on "High" that there is a breeze in the room.
I purchased all the components for a dust collection system
(Oneida cyclone), but I haven't installed it yet.
Bloxygen Boy