Bill Pentz Air Cleaner

[Wilsoncb]

Has anyone tried the Bill Pentz air cleaner?

Dust Collection Research - Air Cleaner

This site is all about dust collection and protection. It shares the risks from fine dust exposure, how to measure your risks and how to effectively protect yourself and those close to you from airborne dust hazards. Fine dust is so extensively studied that researchers call it PM short for...

www.billpentz.com

 

[Rushton]

Yes, I have used Bill Pentz's design for about 8 years now. It works great! We currently have it hanging horizontally from the ceiling in our community woodworking shop. It will clear the air from a particle count of 2500 on our Dylos particle count reader to under 300 in about 8 minutes.

I have blown out the filter (gently from the inside) only one time over the years. The Wynn filter combined with the fan Bill recommends have been an excellent combination.

 

[tvrgeek]

But if a Wynn filter, probably only MERV 15 so small dust and I am sure it works great, but does not filter the ultra fine dust that embeds in your lungs. The reverence article mentions his particle meter, but as I discovered, they measure only the medium size particles and are totally inaccurate. "Real" ones cost upwards of $20,000 and to measure the sub micron dangerous particles, you need a trap and a lab analysis.

Please, I am not picking on this product, but trying to highlight a lot of miss-information and false security offered by these products. In other words, when using MDF or sanding, you need better protection than this.

 

[Rushton]

But if a Wynn filter, probably only MERV 15 so small dust and I am sure it works great, but does not filter the ultra fine dust that embeds in your lungs..

Check the test results Wynn publishes and their discussion of the various standards for testing. Their results chart shows MERV 15 is 89% effective at 0.3 to 1.0 microns and 90.3% at 1.0 to 3.0 microns.

Filter Efficiency - Wynn Environmental

Manufacturers of filters, dust collection systems, and air filtration equipment use different test methods based on their intended target

wynnenv.com

An unrelated further note about WHICH filter to get. For this design you need a filter that works from the outside in, not inside out (as would be used for a vacuum or cyclone application.

 

[creasman]

I copied the design from his site 10-15 years ago. At the time a guy in Colorado was selling kits for the cyclone based on his design (with neural vane inside). I bought the cyclone kit from him, ordered the impeller and housing from some place in Ohio and purchased a 5 HP motor to drive it. It's been running great ever since (had to resist the urge to say it's sucked ever since). I have some fairly long duct runs (30ish feet) and don't have any problems.

 

[Wilsoncb]

But if a Wynn filter, probably only MERV 15 so small dust and I am sure it works great, but does not filter the ultra fine dust that embeds in your lungs...

Correct, it’s a MERV 15, and thanks for the info/concern. I always wear a mask when generating fine or ultra-fine dust. There’s going to be a fair amount of dust in the air until it finds its way into the filter, out the door (or onto something only to be kicked back into the air). Weather permitting, I keep the garage door open with a fan blowing out.

My concern with the arrangement pictured is how well does it work with the intake and exhaust so close together? Also, what about the proximity to the dust being generated. Like dust collection on a tool, I think it’s best to have the cleaner as close to the source as possible. It would seem to make sense to roll it closer to whatever you are working on…or is that not really necessary with an air cleaner (vs. a dust collector)? If it’s mounted on the ceiling like most basic air cleaners, doesn’t it just pull dust up past your nose? Again, the configuration in the picture is good for portability, however it seems like the exhaust ought to extend up as high as possible, then extend horizontal at least 10 feet. Otherwise it might just recirculate the air it just cleaned?

Seems like I’m either overthinking this, or missing something.

 

[Rushton]

My concern with the arrangement pictured is how well does it work with the intake and exhaust so close together? Also, what about the proximity to the dust being generated.

Keep in mind that this is an "air filter" and not a dust collection system. It does not and is not intended to replace good dust collection at the source. In our shop, we use a Clearvue CVMAX cyclone dust collection system connected with 6" ducts to as close to each source of dust generation as we can. That is the real dust removal tool in our shop. But, there are times when the cyclone simply can't capture the dust (whole variety of situations here) and dust gets into the air. That's where a good face mask (as you use) becomes even more important and where opening doors, running fans, and running an air filter all come into play. Dust also gets into the air due to hand sanding, hand saw cutting, and a myriad of tools that can be nearly impossible to capture dust at the source.

Most days when I leave the shop, I leave the Pentz design air filter running on a timer for an hour or so. Then when I return to the shop, the air is as clean and clear as it's going to be. As to recirculation, the blower is very strong. The goal is to aim it to blow as much in a circular pattern around the circumference of the shop.

 

[mpeele]

My concern with the arrangement pictured is how well does it work with the intake and exhaust so close together? Also, what about the proximity to the dust being generated. Like dust collection on a tool, I think it’s best to have the cleaner as close to the source as possible. It would seem to make sense to roll it closer to whatever you are working on…or is that not really necessary with an air cleaner (vs. a dust collector)? If it’s mounted on the ceiling like most basic air cleaners, doesn’t it just pull dust up past your nose? Again, the configuration in the picture is good for portability, however it seems like the exhaust ought to extend up as high as possible, then extend horizontal at least 10 feet. Otherwise it might just recirculate the air it just cleaned?

Seems like I’m either overthinking this, or missing something.

Your concern is warranted. I have a ceiling mounted 750 cfm filter with Wynn MERV 14 vee bag filter. I have tested it with incense sticks which generates mostly 1 micron particles. At 6' form the filter there was no visible movement towards the filter. At 5' all of the smoke made it way into the filter. My workshop is in my basement with no exterior access. To keep dust from migrating to the rest of the house I run two exhaust fans ( 6" and 4" for a total of about 600 CFM). I also have three small fans that sit a floor level to create a circular air flow.

Even when I don't run the exhaust fans and filter the small particles will fall out of the air or attach to ceiling or duct work in a couple of hours. I've been running air monitors for 7 or 8 years which records particle counts for 0.3, 0.5, 1.0, 2.5 and 5.0 - 10 microns. The exhaust fans seem to make more of a difference that the filter and putting the ambient filter on the floor would provide more benefit than the ceiling mounting. For a while I had 3 particle counters running at 3 different levels. The one I have run the longest is mounted at about 5' from the floor behind my miter saw.

Long and short of it is that I would not put a HEPA filter on an ambient air filter. But I would put one on all shop vacs and dust collectors. And if your are really concerned with dust ditch the broom and vac the shop with a vac with a HEPA filter( one of you shop vacs).

 

[Henry W]

Your concern is warranted. I have a ceiling mounted 750 cfm filter with Wynn MERV 14 vee bag filter. I have tested it with incense sticks which generates mostly 1 micron particles. At 6' form the filter there was no visible movement towards the filter. At 5' all of the smoke made it way into the filter. My workshop is in my basement with no exterior access. To keep dust from migrating to the rest of the house I run two exhaust fans ( 6" and 4" for a total of about 600 CFM). I also have three small fans that sit a floor level to create a circular air flow.

Even when I don't run the exhaust fans and filter the small particles will fall out of the air or attach to ceiling or duct work in a couple of hours. I've been running air monitors for 7 or 8 years which records particle counts for 0.3, 0.5, 1.0, 2.5 and 5.0 - 10 microns. The exhaust fans seem to make more of a difference that the filter and putting the ambient filter on the floor would provide more benefit than the ceiling mounting. For a while I had 3 particle counters running at 3 different levels. The one I have run the longest is mounted at about 5' from the floor behind my miter saw.

Long and short of it is that I would not put a HEPA filter on an ambient air filter. But I would put one on all shop vacs and dust collectors. And if your are really concerned with dust ditch the broom and vac the shop with a vac with a HEPA filter( one of you shop vacs).

Wow, real data!
Now we are getting somewhere!

 

[tvrgeek]

Your concern is warranted. I have a ceiling mounted 750 cfm filter with Wynn MERV 14 vee bag filter. I have tested it with incense sticks which generates mostly 1 micron particles. At 6' form the filter there was no visible movement towards the filter. At 5' all of the smoke made it way into the filter. My workshop is in my basement with no exterior access. To keep dust from migrating to the rest of the house I run two exhaust fans ( 6" and 4" for a total of about 600 CFM). I also have three small fans that sit a floor level to create a circular air flow.

Even when I don't run the exhaust fans and filter the small particles will fall out of the air or attach to ceiling or duct work in a couple of hours. I've been running air monitors for 7 or 8 years which records particle counts for 0.3, 0.5, 1.0, 2.5 and 5.0 - 10 microns. The exhaust fans seem to make more of a difference that the filter and putting the ambient filter on the floor would provide more benefit than the ceiling mounting. For a while I had 3 particle counters running at 3 different levels. The one I have run the longest is mounted at about 5' from the floor behind my miter saw.

Long and short of it is that I would not put a HEPA filter on an ambient air filter. But I would put one on all shop vacs and dust collectors. And if your are really concerned with dust ditch the broom and vac the shop with a vac with a HEPA filter( one of you shop vacs).

Unfortunately, unless your monitor cost upwards of $20,000, it is totally inaccurate. Even at that level, they have ZREO ability to measure below 1 micron. Read the spec on the detector modules themselves, not Amazon slick sheets. To do so requires a filter media to be sent to a laboratory for visual counts of particles under a SEM. I tried one, did the research. You do better with a flashlight.