Author Topic: Measuring dust with a Dylos air quality monitor (Read 10551 times)

RobBob · « **on:** November 05, 2016, 11:06 PM »

Found this interesting discussion about wood dust on Matthias Wandel's Woodworking for Engineers website.

Measuring dust with a Dylos air quality monitor
To whet your appetite, here are a few excerpts:

"For his dust collector, which is a ClearVue cyclone with six year old Wynn cartridge filters on the output. The baseline reading in the undisturbed shop is around 93 and 33 (< 2.5 micron and > 2.5 micron). With the Dylos right by the filter, the readings went up to 300 and 40 when the dust collector was turned on, then settled back down to around 250 and 5. Then using the chopsaw (connected to the dust collector) to make about ten cuts in hardwood, the readings went to 401 and 39. Two minutes later, the readings went back down to 327 and 37."

"I'm pretty sure that cyclones alone are ineffective at separating the fine dust. The spinning air inside a cyclone is subject to on the order of 100g of acceleration, but the air only stays in the cyclone for about one second. Assuming particle separation rate is proportional to acceleration or gravity, that would suggest that any dust that can stay suspended in the air for over a minute will also make it through the cyclone.

In fact, I'm getting less enamored with the idea of a cyclone. The coarse dust that a cyclone separates out will also relatively easily fall out of a filter bag. Those low-tech dust collectors with a filter bag on top and a collector bag on the bottom look better all the time."

"All this paranoia is from reading Bill Pentz's pages. One thing that Bill Pentz does not mention directly on his website is that he has wood dust allergies. Having wood dust allergies certainly changes the situation a lot, but most of us don't have wood dust allergies."

"On this subject, I exchanged some emails with Dwight A Kaufman, a doctor who emailed me with his comments. Here are some of his emails below. Food for thought!

Subject: Wood Dust

'Hi, Several years ago I attended an Occupational Medicine Continuing Education Conference at the University of Cincinnati. The main subject was Occupational Lung Disease. I asked one of the lung specialist if wood dust cause lung disease. He answered "No" with no hesitation or reservation. Some people do develop an allergy to wood which may aggravate their asthma or hay fever.'

Dwight A. Kauffman MD

In a later email he writes:

'Yes, you may quote me. I do not have a reference. And I’ll offer the following discourse for those interested:

Our airway, windpipe and bronchi, divide 17 or 18 times before reaching the terminal air pockets where oxygen oxygen and carbon dioxide exchange takes place. In about the first half of these bronchi, there is a constant production of mucus that is continually moving up to remove dust, bacteria, etc.

Most wood dust is trapped in this mucus and removed. Tobacco smoke goes all the way out to the air pockets and some comes back out. Some gets trapped.

Asbestos and silica are inorganic material that can be small enough to get in where the removal system doesn’t work. And being inorganic, the body cannot break them down.

The risk of lung disease from asbestos is greatly exaggerated. For 15 years I worked in a community that had had a factory that made asbestos brake and clutch linings. During those 15 years I did not see or know of anyone with the kind of lung cancer asbestos is supposed to cause.

I did my Internship in western Pennsylvania and saw lots of people with Black Lung disease.

Tobacco smoke damages the airways, thus chronic bronchitis. It also damages the air pockets, thus emphysema. These usually occur together and that is known as COPD.

In chronic bronchitis, the wall of the bronchi are damaged, so that when a person coughs or breaths hard, the airway collapses and traps air. In emphysema, the air exchange pockets that are normally like a bunch of grapes break down and look like an apple, loosing lots of surface area for oxygen exchange with the blood.

COPD is almost totally due to tobacco. Asthma is due to inflammation and causes swelling, increased mucus production and spasm, but does not cause the structural damage that tobacco smoke does.

When a company that makes air filters puts a picture of a chest X-ray in their ad, that is scare tactics.

Air filtration is primarily for comfort and esthetics, not health.

Ninety percent of chronic lung disease and cancer are preventable since they are caused by tobacco.

Asthma and allergies are treatable, and should be treated vigorously.

Dwight A. Kauffman MD'"

Gone · « **Reply #1 on:** November 06, 2016, 11:39 AM »

"Yes, you may quote me. I do not have a reference." from your Doctor KauFman. That info and $1.50 will get you a coffee. Do a simple search of wood related lung problems. OSHA and every other work place safety association disagree. Let me think who am I going to believe a Dr. without any reference to the problem or organizations that have to deal with the problems associated with the industry. Your turn.

John

RobBob · « **Reply #2 on:** November 06, 2016, 12:46 PM »

Quote from: kcufstoidi on November 06, 2016, 11:39 AM

"Yes, you may quote me. I do not have a reference." from your Doctor KauFman. That info and $1.50 will get you a coffee. Do a simple search of wood related lung problems. OSHA and every other work place safety association disagree. Let me think who am I going to believe a Dr. without any reference to the problem or organizations that have to deal with the problems associated with the industry. Your turn.

John

The Center for Disease Control (CDC) is located in the same city where I live. Over ten years ago I met a lady at the local dog park that is a Director at the CDC. She has a Phd from Stanford Univ. Over the course of seeing her a couple times a month for over ten years I got to know Janet, her husband, and son quite well. (Her husband and son are competitive bridge players.)

Anyway, I recently spoke to her about the dangers of wood dust for the hobby woodworker. At my request, she did some research and spoke to her colleagues about this issue.

Bottom line is that there is a big difference between daily occupational wood dust exposure in an enclosed shop vs. exposure to the hobby woodworker. Granted, if you already have a wood dust allergy, asthma or some other existing health problem, your situation might become exacerbated by breathing wood dust. Otherwise, the normal precautions that are typically recommended provide more than adequate prophylactic protection for the hobby woodworker. Wear a dust mask, use dust collection, etc.

Forgot to add, not all wood species cause problems. Western Red Cedar seems to be the worst. Most species are not a big problem except in extreme situations.

RobBob · « **Reply #3 on:** November 06, 2016, 01:24 PM »

I thought Matthias' test of an ordinary fan blowing through a filter was interesting. Seemed to be very effective at cleaning the air.

grbmds · « **Reply #4 on:** November 06, 2016, 02:13 PM »

@RobBob I'm not clear about the point you are trying to make. Is your point that we don't need dust collection devices; collectors, cyclones, air filtration? Just asking . . .

RobBob · « **Reply #5 on:** November 06, 2016, 03:51 PM »

Quote from: grbmds on November 06, 2016, 02:13 PM

@RobBob I'm not clear about the point you are trying to make. Is your point that we don't need dust collection devices; collectors, cyclones, air filtration? Just asking . . .

The point is that imo Bill Pentz overstates the health risk of wood dust to the typical healthy hobby woodworker and is using his hype to sell Clear Vue dust collectors. Clear Vue dust collectors are not markedly better than most other two stage cyclone type dust collectors. Clear Vue dust collectors are not the easiest to properly assemble and seal which is critical to achieving effective performance. The risk of serious illness caused by wood dust to the hobby woodworker is easily mitigated by using a dust mask, dust collectors/extractors, an air filter and common sense.

Clear?

Gone · « **Reply #6 on:** November 06, 2016, 07:05 PM »

"The point is that imo Bill Pentz overstates the health risk of wood dust to the typical healthy hobby woodworker and is using his hype to sell Clear Vue dust collectors."

The only connection Bill Pentz has to Clear Vue is that he has allowed them to use his modified design which he freely offered to the whole industry with no compensation. That's from the original owner of Clear Vue Ed Morgano before the company was bought by the current owners. Bill's son sold his fathers plans initially in the early days. Just to set the record a little straighter.

John

grbmds · « **Reply #7 on:** November 06, 2016, 10:09 PM »

Peter Fedrigon started Oneida and, while a lot of his information is a little too technical, I get the point. A lot of dust floating around your shop is harmful, especially the fine stuff. To do what you can to clear it out of the air is the smartest thing to do. I don't think I'm really willing to take a chance that one "lung specialist" knows the answer. Just because someone sells a product doesn't always mean that he's wrong about what his product does. I don't know which dust collector or air cleaner is the best, but I know that I am doing everything I can to make sure that my family and I breathe as little of the dust I make as possible.

RobBob · « **Reply #8 on:** November 07, 2016, 02:24 PM »

IMO, it is a big mistake to over emphasize the risk of wood dust to the hobby woodworker. It is not as complicated or as risky as some people would have you believe. This just scares people away from the hobby and most of you do not know what you are talking about anyway.

I get real tired of people on these forums being so dogmatic about something they have read about which was written by some other internet "expert".

Internet commandos who spew their opinionated bs about which tool or machine is best for someone else is not helpful to the guy just looking for some common sense pros and cons or a few simple things to consider when making a decision.

Bill Pentz was banned from more than one woodworking forum for similar reasons and some of you are guilty of the same thing.

grbmds · « **Reply #9 on:** November 07, 2016, 03:37 PM »

Quote from: RobBob on November 07, 2016, 02:24 PM

IMO, it is a big mistake to over emphasize the risk of wood dust to the hobby woodworker. It is not as complicated or as risky as some people would have you believe. This just scares people away from the hobby and most of you do not know what you are talking about anyway.

I get real tired of people on these forums being so dogmatic about something they have read about which was written by some other internet "expert".

Internet commandos who spew their opinionated bs about which tool or machine is best for someone else is not helpful to the guy just looking for some common sense pros and cons or a few simple things to consider when making a decision.

Bill Pentz was banned from more than one woodworking forum for similar reasons and some of you are guilty of the same thing.

Sorry, but I don't intend to tell anyone what to do. I know what works for me and, based on what I've read and experienced over 40 years of woodworking as a side business and as a hobby, I would not recommend ignoring the possible risks of breathing significant amounts of wood dust (or any dust for that matter). I have never read anything by Bill Pentz except to check the quote that was posted here. Everything else I have read, though, indicates that maximizing dust collection in my shop is a good thing. Plus, it's a lot less messy to have great dust collection in place.

RobBob · « **Reply #10 on:** November 07, 2016, 04:36 PM »

My comment was a general one and not directed at you, Randy.

No one said anything about ignoring risks.

Do you use a SawStop table saw?

grbmds · « **Reply #11 on:** November 07, 2016, 07:08 PM »

Quote from: RobBob on November 07, 2016, 04:36 PM

My comment was a general one and not directed at you, Randy.

No one said anything about ignoring risks.

Do you use a SawStop table saw?

@RobBob Yes I purchased the SS Jobsite saw the month it came out. It has served all of my sawing needs that aren't satisfied by the TS55REQ and sometimes even in place of the TS55. I have found it is safe, accurate, mobile and compact, has great dust collection. The 2 drawbacks are the miter gauge and the table insert. I solved the miter gauge problem with an Incra gauge. Then, the other day someone posted a link to a site with an after market insert in the thread from the FOG poster who was asking about experience with the Sawstop versus Bosch jobsite saw. I went to the site, read the description, and think I might even have seen it at a woodworking show in Milwaukee installed on the saw in the Sawstop booth (sure looked like it). I believe this will solve the other problem. Had the Bosch Reaxx been out when I bought, I don't know which one I would have bought. I really do like the Sawstop saw. Rarely does a tool satisfy all your needs as it is supposed to. The Domino is one of those. Actually I own the VacSys and that also satisfies all my woodworking needs that I expected it to. I digress. Sorry, I've been rambling.

RobBob · « **Reply #12 on:** November 08, 2016, 04:39 PM »

What follows below is just a general venting comment...not directed at anyone in particular...

This dust collection and risk discussion reminds me of friends reaction when I said that Chick-fil-A sandwiches were over rated. They kept saying that I hated Chick-fil-A sandwiches.

I repeatedly told them, no, I did not say that I hated the sandwiches. Only that I thought they were over-rated. They are good if you get a fresh one, but they are not as good as everyone says they are.

Same thing here on FOG regarding the risk of dust exposure, Amazon reviews and a few other things. Sometimes I wonder about the reading comprehension skills and discernment of other people.

JimD · « **Reply #13 on:** November 08, 2016, 08:02 PM »

I wrote a little piece after looking at the referenced website and several others as I document in the attached. I like Bill Pentz's website and I think it is a good reference for anybody interested in dust collection. He's done testing and other work that is very useful. But I also think he overstates the risk. If you read his stuff, he also needs extra filtering in his house to stay healthy. It isn't just wood dust that causes him health effects, it is air in general. If you need that level of air filtering then you need the 5hp cyclone system he recommends. But I don't have those sensitivities. The government also does not require that sort of air purity as documented in the attached.

I think we need to collect at the source and maybe use a air filter but I don't think we need super size DCs. I use a shop vac with a cyclone and a quasi HEPA filter. The big benefit I see for a cyclone is not cleaner air, it is less cleaning of air filters. I used to use a DC with a cartridge filter and I hated cleaning the filter.

My other strong recommendation is not to do what I did and use a DC with bags with big holes. I think my first ones were 25 micron. That blew fine dust all over my old shop. I think that is worse than no collection at all. I think the worst you should consider are 1 micron bags.

The other way I would justify lesser systems is to compare shop air quality with outdoor air quality. If you are OK outside when it is a bit dusty, then you should be able to tolerate a workshop that is a bit dusty.

RobBob · « **Reply #14 on:** November 08, 2016, 08:19 PM »

@JimD Now that's more like it. Basically the way I feel about the subject, too.

grbmds · « **Reply #15 on:** November 08, 2016, 08:28 PM »

Quote from: JimD on November 08, 2016, 08:02 PM

I wrote a little piece after looking at the referenced website and several others as I document in the attached. I like Bill Pentz's website and I think it is a good reference for anybody interested in dust collection. He's done testing and other work that is very useful. But I also think he overstates the risk. If you read his stuff, he also needs extra filtering in his house to stay healthy. It isn't just wood dust that causes him health effects, it is air in general. If you need that level of air filtering then you need the 5hp cyclone system he recommends. But I don't have those sensitivities. The government also does not require that sort of air purity as documented in the attached.

I think we need to collect at the source and maybe use a air filter but I don't think we need super size DCs. I use a shop vac with a cyclone and a quasi HEPA filter. The big benefit I see for a cyclone is not cleaner air, it is less cleaning of air filters. I used to use a DC with a cartridge filter and I hated cleaning the filter.

My other strong recommendation is not to do what I did and use a DC with bags with big holes. I think my first ones were 25 micron. That blew fine dust all over my old shop. I think that is worse than no collection at all. I think the worst you should consider are 1 micron bags.

The other way I would justify lesser systems is to compare shop air quality with outdoor air quality. If you are OK outside when it is a bit dusty, then you should be able to tolerate a workshop that is a bit dusty.

For the sake of your lungs, I do hope you right. While I don't believe everyone needs a large cyclone dust collector, they do appear to be the most effective. If you are using only one machine at a time, as most of us who are alone in the shop do (except those with exceptional skills), a smaller collector is certainly sufficient. Regardless of standards, the less dust breathed into the lungs the better and, because of that, I have upgrade all filters to true HEPA filters. In addition, I hate walking around in a fine layer of dust, kicking it up in my face all the time. It just doesn't make working in the shop enjoyable for me. So, each to his own. The less fine dust the better.

antss · « **Reply #16 on:** November 08, 2016, 09:34 PM »

A lot of bang for the buck can be had with a single stage collector with a cartridge filter and a Thein baffel. And they take up less room than a cyclone.

Not so good if you have a lot of ductwork though.

JimD · « **Reply #17 on:** November 09, 2016, 08:00 PM »

My current shop is still evolving. I had to have a garage added to the current house to have a shop at all and did the wiring and walls myself to save money. That is all done and one wall of the shop pretty well finished but the other long wall and the end wall are only partially sorted out. One unanswered question is whether I will add a DC. My shop garage is 14x24 so I have to be careful about how many big things I put in it. So far I am pretty happy with the shop vacuum hooked to the dust deputy with an auto-on switch. I do not love moving hoses to the tool I am using but I could reduce that with some PVC and blast gates.

A disadvantage of the DC for me is the track saw and other hand held tools. A DC will not move much air hooked to a 35mm hose. They do not pull against resistance well at all. But the shop vacuum doesn't do well with the planner or jointer. So I kind of need both but do I have space for both. So far, I sweep up after the planer and jointer and use the shop vacuum.

But if I added a DC today, it would be a harbor freight 2hp with a Super Dust Deputy discharging outside. My shop garage is not heated or cooled and I often work with the doors open. So I don't think venting outside will change the temperature of the shop much. If I discharged inside, I'd get a cartridge filter, probably from Wynn. This sort of setup is nowhere near Bill Pentz's recommendation but I think it would be effective at keeping my shop air decently clean. That conclusion is based upon the reported readings from others testing in their shops using similar smallish DCs.

I would not criticize anybody who wants to use a bigger system. I also think my little 110V 15A table saw is OK but lots of people want 3hp or bigger saws. Everybody has a right to spend their money as they want. I am willing to change blades on my table saw to fit the cut I am making and, doing that, I can rip 3.5 inches deep with my 15A saw (in one pass). So I don't see the need for the 3hp. For me the DC logic is similar. I accept a larger unit would move more air, possibly allow two tools to have gates open at the same time, and most brands would be nicer than a HF (possibly all). But I am into figuring out how to get things done at minimum cost. I don't want to waste money on things that are too cheap to work or on things with more capability than I really need. Before pulling out the credit card, it would be wise to look at cyclone systems from Grizzly and others. It might not save money to modify the HF. Or it might not save enough to be worth the effort.

john stevens · « **Reply #18 on:** November 21, 2016, 08:38 PM »

Hi folks, I'm late to this conversation, but I hope I have something worth reading. I've owned a Dylos meter for about three years. Although I've done very little woodworking in my basement wood shop during that time, I've used the Dylos meter enough to be confident that I've got reliable baselines and reliable data when I'm making sawdust. That said, here are some things I've observed.

Baseline particle counts depend a lot on the outside air, and the particle counts of outside are vary a lot from day to day.

The particle counter measures water vapor particles, so the more damp or humid the air, the higher the particle count.

The particle counter is very sensitive and its readings are very consistent. Anything that causes air motion in the wood shop, even just me walking from one side of the shop to the other, will cause the particle counts to rise a predictable amount.

In my limited experience with only two dust collectors that collect dust at the source, I've found that they cause fine particle counts to rise, even if not connected to a machine making wood dust, and even if I'm not making new wood dust. That was true of my Oneida Dust Cobra (which I sold) and is true of my Festool CT-11 (twelve years old and running like new). I believe this is the net result of two things: they cause air motion in the shop, but they don't filter as much fine dust as they stir up. They're great for keeping coarse dust from falling under foot, or spraying all over the work surfaces, but they don't decrease the number of fine dust particles in the air.

On the other hand, my Jet ambient air filters quickly reduce particle counts, even in the 0.5 micron range. (Jet doesn't even make any claims regarding filtration of particles that small.) Contrary to claims I've read that ambient air filters simply blow dust around, they're the most effective collectors of fine dust in my wood shop.

If I don't run any dust collectors or air filters, airborne particle counts in both ranges decrease to baseline over a period of about 5-10 minutes, contrary to claims I've read that particles in the 0.5 micron range remain suspended indefinitely.

--John

Spiff · « **Reply #19 on:** November 21, 2016, 09:39 PM »

Short story to illustrate lung sensitivity:

Up until my teens I had no allergic reaction to pollen whatsoever. I grew up in the country, and come the summer most everyone was sneezing, had itchy eyes, watery nose, all that sort of thing. But not me, ever.

Then one day I decided to try out a new scythe in a meadow at the back of our house. The grass was pretty long, and as I cut, clouds of pollen filled the air around me. It was quite a sight. After a while my nose began itching, then BOOM. I began sneezing and wheezing, and I just had to get out of there.

Since that precise moment of that one day I've suffered badly from heyfever (rhinitis) and it's a real curse. It made me realise the hard way that the effects of exposure don't have to be cumulative. Just one single bad exposure can trip a switch in your body, and that's you. I believe it's the same deal for alcoholics and addictive behaviours btw.

Anyway, my point is that it's worth keeping away from situations where there's a lot of wood dust, even if it's just that one single time you "can't be bothered" to hook up the vac or forgot to bring your extraction. Maybe that one single exposure might be enough to induce a lifetime of material sensitivity or asthma. It may not happen. But then again it might.

bobfog · « **Reply #20 on:** November 22, 2016, 08:47 AM »

I think @Peter Parfitt has committed to doing a video for his YouTube channel on a dust/air quality study in the near future.

josephgewing · « **Reply #21 on:** November 22, 2016, 12:56 PM »

My father, Eugene G. Ewing MD, was a General Practitioner in a small town in Nebraska. His definition - tongue in cheek - of an Expert was someone who was frequently wrong but never in doubt.

Joe
(also a Family Practitioner)

john stevens · « **Reply #22 on:** November 22, 2016, 06:07 PM »

In response to Spiff, I could add my own similar story about housecleaning products. I agree with his caution regarding exposure to wood dust. I want to make it clear that my post wasn't meant to disparage the practice of collecting dust at the source, but to share my experience that ambient dust collectors seem very effective at removing fine dust particles--in the case of the Jet, better even than the seller claims. And to share my experience that dust collection at the tool may not do as much to reduce the fine dust particle count as we're sometimes led to believe.

--John

grbmds · « **Reply #23 on:** November 22, 2016, 10:37 PM »

I have never believed that there is a single solution to dust collection in the shop. Instead, the best result comes from coordination of collection at the source, an ambient air cleaner, and personal dust protection (like masks or powered air cleaning masks). For me, the proof is in the lack of dust laying around on the floor, shelves, and machines after a long session of planing, sawing, sanding, or routing.

JimD · « **Reply #24 on:** November 27, 2016, 06:01 PM »

I've had plenty of exposure to relatively high levels of wood dust. When we cleaned out my old shop, for instance, the air was incredibly dusty. We were moving and had to get it cleaned out. Lots of wood scraps I had held onto forever went to the dump, the tools went into storage along with a little of the best wood, and we swept and vacuumed up. If my hair wasn't already grey it would have looked like it due to the dust. My hayfever is also not as bad as it used to be. Maybe I will be more sensitive to wood dust some day. I plan to keep this shop cleaner so I do not have to do such a terribly dusty cleanup in the future. The old shop got that way due mainly to bad bags on the dust collector. They got the big stuff and blew the fine dust all over the shop. Never again for me. Near HEPA quality or no dust collection.(by near HEPA I mean quasi HEPA filter for the shop vacuum or a cartridge filter on the DC that is near HEPA specs - HEPA would be better but is often significantly more for a little better filteration plus the rating)

Another idea I initially pooh poohed (how do you spell that?) is taking a leaf blower to the shop periodically. My old shop wasn't laid out well for that but this one is. I could start at the back door and blow to the garage door at the other end. With a dust mask on. If it starts getting bad, I think I'll do this. But so far, it seems almost as clean as the house and cleaner than outside.