Shop dust filtration questions

[Brian Brown]

I have heard of woodworkers who use their dust collector to pull air through a ceiling mounted box with a set of filters mounted to the sides. I don't personally know anyone who does this, and I haven't heard any reports of success or failure doing so. While searching this forum for results in doing this, I came across this thread from 2005.

https://sawmillcreek.org/showthread.php?19830-Whole-shop-Air-Filtration-Units-Bad&highlight

I had thought of buying or making a whole shop air filter, but this post makes sense and has me thinking again. I am mostly a turner, and I am only using the lathe, BS,TS, and sanders part of the time when I am in the shop. The dust collection port behind the lathe appears to work well for chips and fine dust, but I have no way to test. So my question is:
If I use a 4" hose on my DC attached to filters that catch 5 to 20 micron dust particles, such as a shop vac filter, and the post filtration air is going through my dust collector with a 1 micron filter, would this not efficiently filter the airborne particles? If so, where in the shop (high, low, center, corner, near the DC, etc) would you place the filter? What else would you use as a filter material? I would close all other blast gates while I am not using tools that generate dust, allowing the full power of the DC to flow through the air filters. I hope this makes sense. Is this an Idea worth pursuing, or is it a waste of time and money? If it matters, my DC is a Delta 1HP. Thanks in advance, I am working on plans to get the new shop up and running.

[Kevin Jenness]

Seems to me you would do as well to let the DC run with ports open near your work area, assuming the DC filter setup is good. If it isn't, that would be the first place to make improvements

[Peter Christensen]

Brian you can test for the dust floating around your shop for about $50US. It will give you enough of an indication of when it is safe to take of your dust mask no mater how you are dealing with the dust. By dust collector, filter box or ventilation to the outside.

https://www.ebay.ca/sch/i.html?_from=R40&_trksid=m570.l1313&_nkw=Household+PM2.5+Detector+Module+Air+Quality+D ust+Sensor+TFT+LCD+Display+Monitor&_sacat=0

[Jim Becker]

A shop air dust filter can certainly help remove airborne particles, but that's going to largely benefit you by helping reduce the amount of dust that settles on surfaces in your shop. That's the only reason I use mine and particularly, I run it prior to and after spraying finishes. For your personal protection, you need to catch the majority of the dust at the source and that's where you want to concentrate on dust collection improvements for your shop.

To your original statement, I personally do not favor using the DC for an air filtration application like you describe. It's a different function. Even the blowers are different between a DC and a designed-for-purpose air filtration system.

[Jim Dwight]

For airfilter ideas you might want to visit the woodworking for engineers website. He tests good furnace filters with simple fans blowing air through them using a Dylos monitor. He also has some ideas on dust collectors - but as a warning he likes good bags. I tried that but I think good cartridges are significantly better.

I had the Delta AP400 DC. If that is the unit you have, I would move it from tool to tool, not try and plumb it through the shop. I did the latter and was not satisfied with the air movement. I used 4 inch S&D and had blast gates at each tool but it did not produce enough airflow for my 8 5/8 jointer. Did OK with the table saw and was not adequate for the CMS - helped but didn't get nearly all the debris.

[Rod Sheridan]

I run my cyclone with a HEPA filter as a shop air cleaner, works great, I use a Dylos particle counter to verify that.......Rod.

[David Utterback]

My experience with the cleaner is that the "clean" exhaust air causes settled dust to become airborne. Almost all of my source capture inlets are inefficient, especially at the table saw with a Shark Guard and the band saw. Do those who use the Dylos see an increase in particulate count after the start or do you keep your shop cleaner than mine with more efficient source capture of dust?