Effective dust collection demo

(Tony) #1

I was wondering how well my homemade dust boot collects dust so I put a Dylos 1100 Pro laser particle counter INSIDE my enclosure while I was cutting MDF. This video also demos how good the enclosure is at attenuating the sound. Yes, the router really was cutting the part in the video :wink: That was a part for the den table I made (den table link here Contemporary den table cut using a Shapeoko3 XXL)

Dropbox link of the video… https://www.dropbox.com/s/284h6cu8xlp77vd/DYLOS%20INSIDE%20S03%20ENCLOSURE%20SHOWING%20NO%20DUST.mp4?dl=0

You can open the link even if you don’t have a Dropbox account. Just X out when it asks you to join.
The two numbers on the meter are particles per cubic foot divided by 100. The left number represents particles 0.5 microns and larger. The right number represents particles 2.5 microns and larger. Anything under 300 for the left number is considered “good” air quality. Anything over 3000 is very poor air quality.

Typical outside air where I live is around 500 to 3000. I designed a high efficiency air scrubber for my shop so it usually stays in the 50-300 range even when the outside air is bad.

As you can see from the video, the air inside my enclosure stays at about the same quality as the shop air. The dust boot does not catch all of the larger particles but I sweep them up in about 10 seconds after a job is finished. But, it does capture all of the small particles, which are the ones that can get deepest into your lungs and cause the most long term health issues.

(Pete) #2

Do you have any information on the air scrubber you designed? I have been thinking about adding this to my shop, but not sure on the best place to start.

(Tony) #3

The most economical route that would still be very effective would be to buy a used 1200 CFM furnace blower off of EBay and make a box to mount it in. Then put one furnace filter on each side for the inlet air. Use the highest rated filters at your local home center and they will do a good job. I mounted the blower by hanging it from rubber bungees to prevent it from resonating inside the box which worked very well.

Mine uses two high end Wynn filters but that’s really overkill. I’ve done some testing just using a box fan and a large furnace filter folded into a V shape and it does a decent job. The box fan setup brings the particle counts down about half as fast as the expensive scrubber I made but I’m guessing a furnace blower with two top end 3M filters from Home Depot would probably work 90% as well. At some point paying for better filters ends up being a waste of money and energy because a top end furnace filter will bring particle counts down almost as fast as a HEPA filter. Its just a matter of having enough air exchanges for the size of your shop. My shop is 24’x32’x8’ and 1200 CFM is about as low as I would recommend going for that size.

Let me know if you have any other questions.

(Pete) #4

I have access to an old furnace blower so I think I might put this up towards the top of my list for shop improvements. Essentially you enclosed the fan in a box and add filters to the air inlet location? How often do you run your air scrubber? Do you see any issues of it kicking up more dust with the amount of air it blows around? I am thinking that I would ceiling mount it on the opposite side of the ceiling from my heater. Thanks for the help and sorry about hijacking your thread.

(Tony) #5

I put one filter on each side of the blower. I would suggest doing the same with two furnace filters. I would actually put two furnace filters on each side. One with a courser mesh size as a prefilter and then a second one that is the highest grade you can find at a home center. By the way, getting a cake of dust on your prefilter actually makes the filter much more efficient at removing dust so as long as the blower has a good flow rate, don’t clean the filter. The dust cake can raise filtration efficiency dramatically.

I run it anytime I’m in the shop. I use a Dylos 1100 Pro laser particle counter to measure dust concentrations and I find that just walking around in the shop will raise dust concentrations to unhealthy levels. With the scrubber running the levels stay well under healthy limits except for short periods after I run a tool that creates a lot of dust. I’ve been systematically making fixtures to catch most of the dust produced by most of my tools.

I mounted mine so the outlet is next to the ceiling and it doesn’t create any direct air flow across any of my work spaces. Any breezes can make it feel 10 degrees colder in the winter. It will stir up some dust that has settled since it was on last but if you run it all the time you are in the shop you won’t have nearly as much dust settling everywhere.

This is a dust collection thread so I think this topic fits well.

(Jude Marleau) #6

I don’t have a dylos but I know this

works well. I built a similar filter box but because I’m in Florida I also built a duct to my a/c . This results in my a/c condenser never pulling in dirty air and needing cleaning and the a/c always pumps out clean cooled air. Without the filter box my a/c condenser would cake up with sawdust and eliminate all airflow thru it (the air filters on a/c’s are worthless) even with dust collection at the machine just the airborne fine dust is actually quite significant. Two birds in one stone. Good topic!

(Adam X) #7

I know I’m dragging up an ancient thread here, but I didn’t want to restart the whole topic for a single question;

@Tshulthise Am I understanding your results correctly that with ONLY the dust boot, the air quality was that good? From a strictly dust-control perspective, would you be comfortable running your cnc without an enclosure, based on these results?

(Tony) #8

That is correct. I guess it depends on what you are cutting and how well your dust boot works. I would be comfortable not using an enclosure as long as the shop had an air cleaner to knock down any fines that make it past the dust boot. That is, for materials that aren’t unusually hazardous.