Alan, that is a very interesting data point. I don't have any way to measure air quality. But I do have an overhead air cleaner. After turning off the dust source about how long does it typically take to get the particle count down?

I am wondering because I don't like running the overhead air filter . It is a little loud and most of my time in the shop is spent quietly with hand tools. I would prefer to turn it off after it has done it's job.

Lets see a little back of the envelope calculation: my garage is 22x22x11 = ~5k ft^3. My Jet says it moves ~1k ft^3/minute. So it will process the volume of air of my garage in ~5 minutes. But how much of that is just the same filtered air being recirculated? Would nee a lot more math to improve the accuracy and lots depends on how efficiently the air moves around the shop. And also the efficiency of the filter. Looks like mine is only 85% at 1 micron. So I am probably looking at 3-4x the time to get the count down.

Thanks!!
Salem