Hi guys,

I'm trying to improve the quality of the air in my shop. I've noticed that I get a sort of tightness in my chest just behind/below my sternum after a day of working in my shop. I have a plan for upgrading my dust collection, so now I'm turning my attention to air filtration.

I have a Jet 1000B air filtration unit, but I now know that it's basically worthless for collecting the most harmful particles (less than 1 micron).

I would like to make my own air filtration units, using two filters each (outer filter for the big stuff, inner filter for the fine stuff). I'd like for the inner filter to be MERV 16, which I understand to be as close to HEPA as I can get. My concern is that the finer filter will cut down air flow too much. My shop is about 450 SQFT with 8' ceilings. The floor plan is close to square, with no solid walls in the middle.

So now, my questions... drum roll please.
  1. What kind of blower is recommended given my MERV 16 requirement and my shop size? Meaning, how much CFM, HP, etc do I need to overcome the filter resistance, without damaging the filter media?
  2. How many filtration units are adequate to create the proper circulation path for the air (I understand you want the air to move in a circle around the shop)?
  3. How much filter media surface area is recommended?
  4. What outer filter should I use? MERV 8 outer filter?


Now let me preemptively rule some things out for you guys so that we can focus on the question at hand:


  • Yes, I know that the best method for reducing airborne dust is to collect it at the source.
  • Yes, I know that air filtration units are only a last resort, and that they can have a tendency to stir up existing dust. My goal is to collect dust at the source as much as humanly possible, and catch anything that escapes via my air filtration units, so that it doesn't have time to settle and be stirred up the next time I'm in the shop.
  • I also know that it can tend to pull new dust (as you're making it) up toward the ceiling and thus up in front of your mouth. To me, this comes down to being smart about where you position the inlets in the shop, and if necessary, wearing a respirator while performing those tasks. But I'm not going to turn the air filtration off during those tasks only to let the dust stay suspended in the air and later settle, only to be stirred up later. Seems like cutting off your nose to spite your face.
  • Yes, I have read Bill Pentz's website. I have a 3HP 4-bag dust collector, with integrated Thien baffles and two huge Wynn Environmental Poly-spun (or whatever they're called) filters. The thing still leaks a lot especially around the bag clamps... and emptying the plastic bags is not fun. So, I have ordered one of the Ebay cyclones (seller name is eastcaroga- nice guy), and plan to use my 3HP motor and impeller with it, and to vent outside.
    • Yes, I know, it will suck the heat outside- I'm willing to make the trade off
    • It's a stand-alone shop, so I don't have to worry about furnaces/etc
    • Yes, I know, I need a gazzillion HP motor and a giant impeller, to do it right but I'm trying to save some money by using the motor and impeller I already have.
    • Yes, I know the Pentz design will separate the dust better, but I'm not concerned about protecting the filter since I'll be venting outside
    • No, I don't have nearby neighbors

  • I have ordered a dust deputy and have a plan for redoing my shop vac setup to capture that dust- it's also a problem for me today
  • I have plumbed the shop with 6" ducting.
  • Yes, I have searched on this topic. There very well might be a thread I missed that answers this, so please feel free to include it here!


Please, don't bring any of the above items up- I would really like us to focus on my question! I've read a lot of threads where people ask this kind of question, the thread gets overwhelmed with responses about the items above, and the question never ultimately gets answered.

Thanks in advance!!

Peter