I choose:
6 - NONE OF THE ABOVE!
First, lets do some quick calculations. Your shop, 32x32X8 = 8,192 Cubic Feet. For effective dust filtration, you need to "change or filter the air" AT LEAST 6 times per hour. SO, lets multiply 8,192 (the size of your shop) times 6 (the minimum number of times you need to change the air). That number is 49,152. THIS NUMBER equals the total volume of air you need to move PER HOUR.
NOW, lets divide 49,152 by 60 (number of minutes in an hour). That number is 819.20. So, you need a device that will move 820 CFM (cubic feet per minute).
Next, go to your local HVAC "replacement" company that upgrades air conditioners, heat pumps and furnaces. Tell the nice gentleman (or lady) that you need a "squirrel cage" blower that will move 800 CFM. They'll likely GIVE YOU the blower, if you remove it from the air handler. THE ONLY ISSUES with getting a BIGGER blower is that it will be a little louder and use a "little" more electicity. (I'd try to get a 1200 CFM blower, as these are REAL common, here).
Once you have the "squirrel cage" and know that it runs, go to Rockler or Woodcraft and buy a 1 micron (or better) "bag" filter. These cost about $35 (and it killed me to pay retail for this).
Then go to HD or Lowes and buy a 16X20 (most common size) "washable' or "electrostatic" furnace filter. These cost about $15.
Then, google "Shop built dust filtration system" and you should find my plans (Ithink my plans are still on Saw Mill Creek) and others on how to build the entire thing out of MDF or plywood.
Follow these straightforward plans and you'll have a MUCH BETTER air filtration system than you can buy for $250-$500.
NOTE: for best results, hang the filtration system as close to the ceiling and center of the shop as you can.
With any luck, you can have a system that will move 1200 CFM for about $50.
Respectfully submitted.
