I made my own air cleaner with a furnace squirrel cage fan and motor, you can easily salvage one of these or check with a heating and cooling company and I'm sure you can score one from them. The design is really simple, just a 3/4" plywood box to house the fan and motor. I made a slot big enough to hold 2 furnace filters that just happen to be the same size as my house furnace filters, i always have them on hand and buy the better ones in bulk pacs. Then I cut a square hole for the exhaust side and screwed an air grate to that. It works great!!! If the fan can recirculate the air in you house many times an hour how fast do you think it will clear the air in your shop? Real quick I can say. Here's some pics
Just a simple on off switch.
Here you can see the exhaust side.
Here you can see how I double stack the filters. I can rotate them as needed. When the front one becomes plugged and I can't clean it with the shop vac anymore I discard it and put the back filter in the front and a new filter in the rear.
Here you can see how the squirrel fan mounts inside the box.
Here's a pic of the filter slot, all made out of scrap 3/4" plywood screwed and glued together.
You can put the air cleaner anywhere, I just put it under the work bench and it circulates the air in the shop well and I don't hit my head on it, lol.
This thing really works amazing, better than I expected it to work. It was supper cheap and easy to make. Guys you should make one of these instead of spending big bucks on a store bought one. I have 2 dust collectors in my shop and this and it works very well, especially if I'm sanding on the work bench above.