# Dust Collection Upgrade to hard pipe questions



## eflanders (May 2, 2013)

In my basement based workshop I currently have 7 machines hooked into my Delta 1.5 hp DC unit. All lines into it are currently 4" flex pipe and I have never had any issues with collecting any shavings. Notes: a). I dress quite a bit of rough-sawn lumber and can easily fill a bag of shavings in a shop work day. b). Recently I added a Wynn nano filter to the existing DC and it was a good improvement in the ultra fine dust collection that was needed. (Air-born fine dust previously was having to be extracted via 2 suspended air filtration units which only catches about 80%-90% of the ultra fine dust.)

*Could I improve things even more by adding a cyclone or separator?
Have you noticed a substantial improvement in suction using hard pipe vs. flex?
Will I gain more air flow by using a 6" hard-pipe main line with 4" flexible drops to each w.w. machine? 
What connector(s) are used to go from the 4" PVC to the 4" plastic flex tubing? 
Is the pipe o.d. different for schedule 20 vs. schedule 40 and does it require a different connection to the flex?
Other than keeping small cut-offs from hitting the DC impeller, what advantages does a separator really give you? 
How easy and messy is it to empty the dust / shavings bin when using a top-hat, baffle or cyclone separator vs. the plastic bag currently on my DC unit? 
What connection do you use from the cyclone or separator to the dust bin?
I have a maximum ceiling height of only 8'. Based on this, would you recommend a cyclone, baffle or top-hat separator and WHY?
*
Thanks in advance for your insight and advice!
Eric


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## rwe2156 (May 7, 2014)

> *Could I improve things even more by adding a cyclone or separator?


Cyclones degrade CFM's. The only real advantage is chip collection.



> Have you noticed a substantial improvement in suction using hard pipe vs. flex?


There will be a significant increase in air flow, especially with this much ducting.



> Will I gain more air flow by using a 6" hard-pipe main line with 4" flexible drops to each w.w. machine?


Absolutely!



> What connector(s) are used to go from the 4" PVC to the 4" plastic flex tubing?


I slip the flex right over the pvc. It helps to remove a few inches of the wire from the flex then just clamp.

Yes. For sch 20 the flex will slip over.



> Other than keeping small cut-offs from hitting the DC impeller, what advantages does a separator really give you? How easy and messy is it to empty the dust / shavings bin when using a top-hat, baffle or cyclone separator vs. the plastic bag currently on my DC unit?


 Much easier!!



> What connection do you use from the cyclone or separator to the dust bin?


About a 2 foot piece of 6" flex.



> .I have a maximum ceiling height of only 8 . Based on this, would you recommend a cyclone, baffle or top-hat separator and WHY?


The Jet cyclones are a little over 6' tall. There may be others.

- eflanders
[/QUOTE]


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## wapakfred (Jul 29, 2011)

Just a point about the improvement of the ultra fine dust collection you perceived. The filter will undoubtedly separate more of the fine dust particles from the air stream than whatever it replaced. But real improvement would be in capturing more of the fine particles and it didn't do much to improve that part. It takes air flow to catch the finest dust, as you see the larger stuff is fairly easy to catch. Unless you catch them at the source, they are still getting into the ambient air. So any of the improvements you want to make that will increase air flow would be a good thing. One other thing, the air filtration units are a good thing, but do little for your health….by the time they catch the dust it's already in your lungs.


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## bkseitz (Oct 24, 2014)

Many of the questions have been answered above. Just to add-on: Cyclone will lower CFM, but improve dust collection by protecting your blower from large chips, etc. Duct size and dust collection efficiency is not a certainty a few factors interact and effect that: Blower CFM, smoothness of duct surface, straightness of airflow path, distance between blower and collection point, resistance of filtering surface, and size of ducts. The basic advice is reducing resistance of airflow is what gets you better collection.

If you're not in a hurry, check out my Project Blog on Air Quality. I'm in process of building out several systems to improve air quality in my shop: Dust Collection, Shop Air Filter System, and Power Air Respirators. It is not likely to be as detailed as Bill Pentz site, but may help the average joe on a budget like me


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## AZWoody (Jan 18, 2015)

I really am not sure that going to 6" will help in getting more cfm. If your motor and impeller are not big enough, your air speed inside a pipe that size will not be sufficient to move the particles and you'll end up plugging up and having more problems than with a 4" pipe. I think 5" might be the largest with what you have but can't be more positive unless you know the fan curves for what you have.

Another benefit of some sort of separator, other than protecting the impeller is it will improve the life of the filter. It will help keep particles down that get to it so there will be a much longer time in between needing to clean and or replace.

As for types of separators, in my experience, unless you're trying to move lots of volume they're going to work pretty much the same. I've done side by sides of the Oneida super dust deputy cyclone and a plastic separator that sits on top of a trashcan and there was no difference in terms of cfm loss.


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## AZWoody (Jan 18, 2015)

> One other thing, the air filtration units are a good thing, but do little for your health….by the time they catch the dust it s already in your lungs.
> 
> - Fred Hargis


This is something very important to understand. If you're not catching it at the tool, you will breathe it, unless you're wearing a respirator of some sort.


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## Sundowner (Feb 6, 2013)

> I really am not sure that going to 6" will help in getting more cfm. If your motor and impeller are not big enough, your air speed inside a pipe that size will not be sufficient to move the particles and you ll end up plugging up and having more problems than with a 4" pipe. I think 5" might be the largest with what you have but can t be more positive unless you know the fan curves for what you have.
> 
> - AZWoody


this. you need to match your piping size to collector size, the length of the ducting runs, and the needs of the equipment it serves. I have a 6" PVC ducting trunk line that runs about 25' off of 7" inlet on a 3HP Oneida. After that, it drops to 4" PVC then flexible ducting line to the smaller tools like the band saw and chop saw, but stays at 6" straight through to the planer/jointer and table saw. if you go big the whole way, even on a big collector, you will lose velocity in the duct. you need to step-down the duct diameter the further out you go to maintain enough velocity to carry along the dust and chips.


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## bkseitz (Oct 24, 2014)

@AZWoody,
Air Filtration Units can assist but most of the common placement is wrong (overhead). Placing an Air Filtration Unit overhead actually makes the problem worse immediately in that you are creating an airflow from the floor up past your head to breath in. Placing it at ground level or below bench level with exhaust piped above will create a downward flow of dust away from you to breath in.

I'm brainstorming with Dick Wynn on a cost efficient (read that as cheap) air filtration approach to do such see blog. I hope to have test results to post by this spring/summer. I had used a similar method for creating IT clean rooms which required much more control over particles


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## JeffP (Aug 4, 2014)

> One other thing, the air filtration units are a good thing, but do little for your health….by the time they catch the dust it s already in your lungs.
> 
> - Fred Hargis
> 
> ...


I'm sure this advice was well intentioned and believed by those who posted and re-posted it, but I call bull******************** on this notion.

If you're only in the shop for a couple seconds while you cut/route/plane/sand something, then sure…this would be true.

But if you are a normal woodworker this is bull hockey. Woodworkers make dust and then they stand there and breathe it for awhile before they make some more.

No question that removing as much as possible at the tool is a good thing. Does that mean that removing some more from the air after it escapes from the tool does no good. No. it. does. not. period.


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## eflanders (May 2, 2013)

My ceiling hung units do a lot to prevent dust from travelling outside of the shop. But I am going to try to relocate one of them to the floor as that idea seems to make a lot of sense see to me. It's worth a try anyway, right?


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## AZWoody (Jan 18, 2015)

> I m sure this advice was well intentioned and believed by those who posted and re-posted it, but I call bull******************** on this notion.
> 
> If you re only in the shop for a couple seconds while you cut/route/plane/sand something, then sure…this would be true.
> 
> ...


You have it backwards. If you're just cutting for a few seconds then leave, then you really aren't going to breathe in as much but if you're in the shop, for long periods, standing and working in a room full of sawdust, then it's a health problem. Maybe you're not having issues but there are people that do. The trade off is in what money people are willing to spend and only they can prioritize where the safety and health risks.

An ambient air cleaner has to suck dust out of the air. Your lungs, suck dust out of the air. If it's in the air for one, it's in the room for another. An ambient air cleaner does not take all the dust out of the room within seconds. It can take hours. Just because the cfm rating may make people think they're circulating their shop space x many times per minute doesn't mean it actually is. Those type of filters are not great at suction. Within a couple feet, maybe that, they can pull particles into the filter. Go further out and dust will be hanging there much longer and may end up settling to the ground before it has a chance to get taken out of the air. Then, it gets kicked back up from walking by.

There would actually need to be one large filter and fans to help circulate or have several filters in various parts of the shop to create some kind of flow to keep the air moving. In a rectangular shop, which most have, there are so many dead spots, such as corners, around machinery, workbenches, etc that stop the movement of air there is just no way a single filter can effectively clean a shop's air.

That is why I said there still needs to be use of a respirator if you cannot collect the dust at the machine.
Calling bull******************** because something isn't important to you dismisses the health effects that sawdust can and does have on many people.


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## wapakfred (Jul 29, 2011)

> Calling bull******************** because something isn t important to you dismisses the health effects that sawdust can and does have on many people.
> 
> - AZWoody


+1, being in denial about the health risks isn't unusual…I know a few smokers who claim it doesn't harm their health.


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## Bill7255 (Feb 23, 2012)

No doubt catching the dust at the source is the best. However it is very difficult or impossible to collect every particle. Some will escape. The purpose of the air filtration unit is to capture as much of this as possible, not letting it settle. Just walking through the shop will stir up dust that has settled, especially the really fine dust. I run my air filtration when out in the shop and set the timer for two hours once I leave. IMO you need good collection at the source and it is beneficial to run a air filtration system.


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## bkseitz (Oct 24, 2014)

As mentioned above I'm working on a new approach to air filtration this year here is the brainstorming I've come up with at present using concepts from IT Cleanroom designs. Not fancy but the idea is to create a constant downdraft away from your head and therefore your lungs rather than have it drift upwards to an overhead air filter.

I'll be testing out the approach after I finish my dust collection project this month. Results to be posted for each after completion as well as handed over to Dick Wynn whose been helpful in brainstorming ideas to keep the costs reasonable.


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## AZWoody (Jan 18, 2015)

> No doubt catching the dust at the source is the best. However it is very difficult or impossible to collect every particle. Some will escape. The purpose of the air filtration unit is to capture as much of this as possible, not letting it settle. Just walking through the shop will stir up dust that has settled, especially the really fine dust. I run my air filtration when out in the shop and set the timer for two hours once I leave. IMO you need good collection at the source and it is beneficial to run a air filtration system.
> 
> - Bill7255


With the proper size dust collector, proper ducting and modifications to the machines, collecting the dust to make it safe to breathe in the shop is possible. If that was not the case, OSHA would be shutting down every furniture shop in the US. The question is, is it affordable, or a priority in terms of cost for the hobbyist.

I agree that an air filter will help, but not in tight conjunction with a dust collector so that you can leave off the respirator or some kind of dust mask. In the end, you can do what you like in your own shop and home. Others can make decisions on what is important for themselves.

Bkseitz, I believe you are on the right course but depending on the size of the shop, there still needs to be multiple units or fans in other areas of the ceiling to create the downdraft and proper circulation. The dust has to be moved to the filter because after a certain distance, the blower does not have the suction to draw particulates to it. Air flow throughout the shop is key and square rooms filled with machines and tables kill the flow.

I am interested to see what you come up with. I'm also trying to figure out some other ways to grab the dust from some of the things that I do in my shop that I can't use my dust collector on.


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## clin (Sep 3, 2015)

I find bkseitz idea intriguing and it has merit. Whether practical or not, we'll have to see how it work out.



> One other thing, the air filtration units are a good thing, but do little for your health….by the time they catch the dust it s already in your lungs.
> 
> - Fred Hargis
> 
> ...


I don't completely agree with this. While an ambient filter is not optimal compared to collecting at the tool, and won't guarantee you breathe in no fine dust, you sure as heck or going to breath a lot less in than if you don't run it.

As mentioned, there are dead spots etc. But these filters move something like 1000X more CFM than your lungs. The dust is much more likely to go into the filter than your lungs. Though again, some will get in your lungs.

And I agree with the comments concerning that fact it doesn't clean the air as fast as a simple calculation based on CFM. Even with complete airflow (no dead spots), it would follow an exponential decay. But I'm sure that is wildly over estimating how quickly it works.

I don't have a DC yet, just Dust Deputy and shop vac with HEPA filter. I also run a Jet ambient filter. But I wear a respirator any time I'm using the table saw or router. And I keep the respirato on for at least 15 minutes (usually longer) after running those tools.


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## JBrow (Nov 18, 2015)

eflanders,

I am just another woodworker, but one who spent several months reading and researching dust collection before upgrading. I upgraded to a cyclone dust collector and installed SDR-35 Sewer and Drain Pipe as central piping to my various machines. From my research and experience I will attempt answers your questions:

Generally, optimizing dust collection requires consideration of several factors: Point of Tool Dust-Pickup, Suction, Air Flow, Static Pressure, and Filtration. Static pressure is the enemy because it resists air flow, slowing air down. Pipe material, long runs of piping, fittings, and filters are some things that add to the static pressure of a system and thus reduce air flow. Air flow and suction are friends because these forces draw in and move dust through the piping to the dust collector. Air flow must be kept at 4000 feet per minute. Otherwise debris can settle in the piping. The Point of Tool Dust-Pickups direct air flow at the tool into the dust collection system and can dramatically affect air quality. Some designs are better than others but none collect 100% of the debris at the tool. Filters are great when they are clean. Dirty filters reduce air flow and directly impact air quality.

Regarding health, in my experience after spending several hours in the workshop with an inferior dust collector, my sinuses filled with dust, which was more of an inconvenience than an immediate health hazard. Those very small dust particles not trapped in my sinuses entered my lungs and are probably there to this day. Fortunately, I rarely used exotic or tropical hardwoods, which contain hazardous chemicals. While I am still healthy after years of woodworking, my concern is that I may develop a wood allergy. As one ages and is exposed to potential allergens like wood dust, one can develop an allergy when none existed before.

Could I improve things even more by adding a cyclone or separator? Yes. The cyclone will protect the filter. The cyclone separates the larger debris from the smaller debris before the dirty air enters the filter. Adding a cyclone will lengthen the time between filter cleaning. Not all cyclones perform equally. Some cyclones, the ones with a longer tampers will separate more fine dust out of the air stream than short cyclones. But all cyclones will separate large from small debris and are good for protecting your filter.

Have you noticed a substantial improvement in suction using hard pipe vs. flex? Yes, definitely. A flex hose, whether smooth walled or corrugated, increase static pressure, and thus reduce air flow. Bill Pentz at

http://billpentz.com/woodworking/cyclone/ducting.cfm

provides the Hazen/Williams (H/W) friction factors for several conduits. The higher the factor the lower amount of friction loss there will be in the pipe system. In other words, the larger the H/W the better. These are: 60 for Corrugated Steel Duct (probably similar to flex hose which was not given); 90-100 for Spiral Duct; 110-125 for Laser Welded Steel Duct; and 146 for PVC. My conclusion is PVC is way better than flex hose in moving debris. But PVC has problems which include static electric discharges - probably more of a nuisance that a hazard.

Will I gain more air flow by using a 6" hard-pipe main line with 4" flexible drops to each w.w. machine? It is hard to say whether 6" would be better than 4" flex hose (which I assume runs back to the collector). Replacing the flex hose with smooth walled piping would be a good choice because there will be less static pressure from the piping. However moving from 4" to 6" or even 4" to 5" may be problematic. Your 1-1/2 horsepower dust collector may not offer enough air flow to maintain this 4000 fpm within 6" or 5" piping. It can be calculated for your dust collector if you have enough information and can tolerate the tedium. I am not that patient.

Therefore, I would opt for 4" pipe; unless you are considering an upgrade of your dust collector in the future. 1) If this upgrade is not your future, then 4" smooth walled metal or PVC piping would be my choice. 2) If a dust collector upgrade is in your future but not now, then making due with the flexible duct work makes the most sense. 3) If an upgrade is in your future and you decide to upgrade now, then 6" would be the way to go if you upgrade to a system with enough power. Installing centralize duct work is expensive and time consuming, so doing it once is better than re-doing everything even several years down the road.

What connector(s) are used to go from the 4" PVC to the 4" plastic flex tubing? You may be able to find an HVAC fitting that would work. However, I made the connection from the solid SDR-35 pipe to flex hose by shrinking Outside Diameter of the end of the PVC. I did this by heating the end of the PVC with a heat gun until flexible. The heated PVC was placed in a 3 part die made from 3 layers of 1/2" MDF glued and screwed together. One part of the die went inside the heated pipe. The remaining 2 parts were placed on each side of the pipe and drawn together with clamps. These outside portions of the die were held down to the ¾" plywood base with cauls. Once cooled the pipe was removed from the die. Paste wax was applied to the MDF to help release the cooled pipe. The outside diameter of the pipe could now accept the flex hose.









PVC Shrinking Die

Is the pipe o.d. different for schedule 20 vs. schedule 40 and does it require a different connection to the flex? I do not know. I used SDR-35 because it is less expensive. Landscape suppliers may be a source. I also used Sewer and Drain fittings to make bends and wyes. I made flex hose connections as described above. I used a similar process for fitting blast gates - just a different die to expand the pipe diameter so the blast gate flange would fit inside the pipe.

Other than keeping small cut-offs from hitting the DC impeller, what advantages does a separator really give you? The big additional advantage of the cyclone is reducing the amount of debris making its way to and clogging the filters. I suspect the cyclone is a more efficient separator than the other separators you mentioned.

How easy and messy is it to empty the dust / shavings bin when using a top-hat, baffle or cyclone separator vs. the plastic bag currently on my DC unit? I hate emptying the dust collection bin. My solution to make this job as easy and clean as possible was to construct a Dust Collection Chamber. I open the Dust Collection Chamber door and slide out the fiber Dust Collection Drum. The empty Dust Collection Drum slides back into place and the door is closed - done. I do not use plastic bags because it is another step in the emptying process, it can get sucked into the collector without a hold down mechanism, and the bags can tear, creating a mess - one you might not notice until the wife mentions it on your way out of the house.

What connection do you use from the cyclone or separator to the dust bin? I constructed a Dust Collection Chamber and married it to the cyclone as follows:

The Dust Collection Chamber is a box from plywood and is a permanent part of the dust collector. It is sized in length and width to accept the Dust Collection Drum. The cyclone outlet penetrates the top of the Dust Collection Chamber and is approximately flush with the top on the inside of the Dust Collection Chamber. The door is constructed from ½" plywood with 2" x 2" lumber around the perimeter of the plywood, to keep the plywood flat. The door has a piano hinge and is locked with three window sash locks to draw the door tightly closed. The door is sealed with 1" wide flat felt weather stripping. The joints of the Dust Collection Chamber are sealed with silicone.

The fiber Dust Collection Drum is outfitted with a handle. A bicycle inner tube is attached around the top of the fiber drum and provides a seal with the top of the Dust Collection Chamber. The height of the inside of the Dust Collection Chamber is about ¾" greater than the height of the fiber drum before attaching the bicycle inner tube.

A polycarbonate viewing window is added on the top outside of the Dust Collection Chamber. Two LED under-cabinet puck lamps are mounted on the outside of the Dust Collection Chamber and polycarbonate sheets are mounted to the inside top of the Dust Collection Chamber to protect the LED lamps. The polycarbonate is sealed with silicone and remains relative dust free. This allows me to simply look inside the Dust Collection Chamber to determine when it is time to empty the Dust Collection Drum.









Dust Collection Chamber

I have a maximum ceiling height of only 8'. Based on this, would you recommend a cyclone, baffle or top-hat separator and WHY? I recommend a cyclone, but I am not familiar with the performance of the Thein Baffle or the top hat separator. All will work to separate large from small debris. I suspect the cyclone, used in industry, is more efficient.

I upgraded to the Clearvue CV 1800. It went into my garage workshop with a ceiling height of 101". The motor and impeller housing set atop of the cyclone. The Dust Collection Chamber is at the bottom. The entire assembly sets inside a tower made from 2" x 3" lumber and skinned with ½" plywood. I put the tower on castors and I left 2-3" from the top of the motor to the ceiling. This just right fit was achieved at the expense of dust collection capacity. I purchased a 47 gallon fiber drum. It was too tall to fit inside the Dust Collection Chamber, so I cut the height of the fiber drum down to size. I now have 40 gallons of dust capacity.









Cyclone Sketch









Cyclone Photo - GO CATS!


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## JeffP (Aug 4, 2014)

> I m sure this advice was well intentioned and believed by those who posted and re-posted it, but I call bull******************** on this notion.
> 
> If you re only in the shop for a couple seconds while you cut/route/plane/sand something, then sure…this would be true.
> 
> ...


As is often the case, people read what is written and then invent something out of that they can argue with. As the Monty Python skit went so many years ago "I'd like to buy an argument. No you wouldn't. Yes, most certainly, I would like to buy an argument!".

As clearly and well stated in my post, at the tool DC is very important.

Ignoring the need to remove the dust that escapes from even a well designed and implemented DC system with an air filter is ignoring the health concerns. My post in no way ignores the health concerns.

If you don't want to filter the dust that your DC misses in your own shop…fine with me.

In fact, if you want to pretend I said something different than what I actually said in order to pretend you are an expert in the field, I'm ok with that too. Your advice is worth precisely what I paid for it; just as mine is.

There…I have provided you with an excellent argument. I expect prompt payment for same.


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## BillPentz (Jan 12, 2016)

I could bore you to death with too much information as a few emails have requested. There is a lot of really good and correct information being shared here. What would be best for the original poster's health would be to move his basement shop to the garage, put his DC outside where it vents outside, plus open both sides of his shop with a good commercial fan blowing the air through the shop. Additionally, a good NIOSH approved dual cartridge respirator with 0.3-micron rated cartridges should be put on before starting woodworking. Our particle counters show the vent fan and mask need to stay on for about a half hour after we stop making dust. If the garage shop attaches to his home, he also should put a small exhaust fan that turns on with his shop lights to create a negative pressure to keep the dust out of his home.

For the best chip collection with his current 4" ducting and system a trashcan separator will greatly ease the overhead of emptying the dust collector. Adding a cyclone will seriously kill the airflow needed to even get good chip collection, meaning collecting the same sawdust and chips we would otherwise sweep up with a broom. Unless we use huge trashcan separators we need to use a cyclone when the ducting size increases over 4" or the airflow climbs much over about 350 CFM at each machine.

Trying to get good fine dust collection in a basement shop is tough. Every twenty pounds of sawdust makes enough fine dust to cause 15,119 typical small shops to fail an EPA air quality test, so every 1% missed can cause 151 typical sized shops to fail an EPA air quality test. Fine dust lasts forever unless it gets wet and just about any air current will spread fine dust all over contaminating all shared air. Most tools leak fine dust and spray it all over which couples with insufficient airflow to make almost all dust collectors and cyclones miss at least 15% of the fine dust. The dust that escapes collection, known as fugitive dust then builds and builds. Our particle counters show that shops who vent inside generally build so much fine dust that just walking around without doing any woodworking will stir enough airborne to fail an EPA air quality test. Basement shops generally share air with our homes, so our homes also become badly contaminated.

Like smoking tobacco the damage from fine dust with each exposure is so tiny we can go a lifetime before the damage turns into asthma, COPD or worsens other health problems. Unfortunately, the damage is a dose response relationship where the higher and longer the exposure the greater the damage. Dust buildup causes workers in small shops that vent inside to get more fine dust exposure in a few hours than full time workers in large commercial shops that vent outside get in months. The insurance data on large shop workers is horrid with all having problems. For those of us with our shops attached to our homes, my respiratory doctor says children suffer the most from the continuous exposure. Frankly, for many this is one of those who gives a s*** because even with our much higher exposures we don't feel a thing and nothing generally happens for years if not decades.

For some like me this exposure can create much more immediate problems. If you work a poisonous wood such as yew, hemlock, mandrake root, mimosa or oleander, letting the fine dust build in your shop can make you and all close to you very sick, create bad nerve damage, and even kill you. I think working toxic woods is stupid. If you work strongly irritating woods such as black locust, blackwood, cocobolo, greenheart, mahogany, mimosa, olive wood, etc. you can get really sick, develop chronic nasal and sinus infections, skin rashes, etc. Sensitizing woods cause you to build worsening allergic reactions even if you were never allergic before. Most woods to some degree are sensitizing, but some woods such as rosewoods and cocobolo can cause an allergic reaction to develop in just a few hours exposure. It can then take decades to shake these allergies. The big problem I learned the hard way about sensitizers is if your shop and home are contaminated, soon your lungs and airways get full of the very dust that triggers an allergic reaction. Then, that reaction can be really bad because we can't get away. Mine sent me to the hospital and killed my woodworking for more than a decade.


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## bkseitz (Oct 24, 2014)

@BillPentz -Thanks


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## eflanders (May 2, 2013)

Bill,
I respect the research that you have done and appreciate your feedback. However, some of your suggestions are not possible or practical for me. I do not work with the toxic woods, but I do work with many of the ones that can be irratable. I live in far NE WI. Tomorrow our Temps will be a high of 8' F. Venting outside is just not practical or cost effective. I do run my air filtration units well after I am done working. This morning I moved one of the units to the floor and it seems to work better having one in one corner at ceiling height and one at the opposite corner on the floor. This was a good suggestion by one of the L. J.s! My recently added Wynn filter has helped a lot in preventing ultra fine dust from being spit out by the former woven bag filter. I am going to build or buy some sort of separator soon but the changes made already have made a nice improvement in visible dust throughout the home. I'm assuming by the comments posted so far that this will add life to the cartridge filter and the impeller. I just hope it doesn't lessen any air flow! By the way, when I hand sand, I have a Fein vac hooked directly to the sander. This catches most of the dust in the hepa filter of the vac. My belt sander is hooked into my big DC system.


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## clin (Sep 3, 2015)

Bill,

Thanks for a great post. I know you probably get a little frustrated with the lax attitude many have about dust. Be assured there are people, me included, that are paying attention to what you have to say. You are almost certainly improving the health of many woodworkers.

You've mentioned attached shops and basement shops in particular. I have recently converted one bay of a 3 car garage to a shop space. I've walled it off from the rest of the garage. There is a door leading from the shop directly into my home as well as one into the garage, through the new wall.

Although the shop now heated and cooled, it is not tied into the house ventilation system in any way. Also, the door leading into the home is a fully weather stripped exterior door.

Does this type of setup have the same issues as a basement shop, or am I at least not likely to be pumping fine dust throughout my home?

Of course any dust on me and my cloths can be carried in, but that's an issue regardless of how the shop is attached (or not).

I'd appreciate your thoughts.


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## JeffP (Aug 4, 2014)

For the OP and others for whom cold weather makes outdoor venting impractical…what about splitting up your shop?

I'm thinking maybe you could move just the worst offending fine dust makers like sanders "outside", while doing your bandsawing and drill pressing and hand-tooling indoors?

The most used tool for most of us is the table saw. I'm guessing it falls somewhere in the middle range of fine dust creators, so that probably reduces the usefulness of this idea somewhat.

Now that I'm thinking about it some more…sanding is for most of us among our least favorite parts of the hobby. Taking it outside in sub-freezing weather may make it completely intolerable. Maybe switch to a card scraper?


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## Holbs (Nov 4, 2012)

Bill… another group hug. Because of your passion, I have stepped up my dust collection practices.

Eric (awesome name, btw)...
cyclone? I have a 3HP Grizzly dual wynn canister setup for total price of $600. It works amazingly well.
Hard pipe vs Flex? Common sense on that one: hard pipe 500% more efficient than flex. I went 6" HVAC duct route instead of PVC just because I can get HVAC and wye's alot cheaper than PVC variant. 
My Thein Baffle saves my impeller but also fills up my 55gallon barrel (much easier to dispose of) and saves wear & tear on my 2 Wynn Filters. That is a HUGE advantage compared to the minor CFM loss (again, I have 3HP not 1.5HP). I put a 55gallon trash bag in the barrel for easy disposal as well.


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## josephf (Aug 29, 2012)

I have some different experiences .I have a 1hp and 1 1/2hp collector .I also believe the 6" pipe is to much for a 1 1/2hp collector just strikes me as to small a unit .though i only run one flexible hose from mine .cannot imagine doing much more with it . I direct vented mine outside -this upped the suction .Put an ebay cyclone in front of it .Did not see any noticeable drop in suction but sure cut down dust going past collector . i am for the cyclone . thinking that you should not expect to much from such a small unit .just my present experience .


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## BillPentz (Jan 12, 2016)

> ... Venting outside is just not practical or cost effective…
> 
> - eflanders


Eflanders, Clin, JeffP, et al,

I often hear about having to work in a basement because the garage is too cold. A good friend of mine is a heart surgeon and avid woodworker. After verifying with his hospital particle meter that he was badly contaminating his home, he moved his whole woodworking operation from a basement shop to his garage. He says he is very comfortable in the coldest weather and vents his 5 hp cyclone outside. He lives in northern Canada. The trick is instead of fired or radiated heat, he uses infrared heat which heats directly without having to heat the air. He says three heat dishes keep him comfortable down to -20. Sadly, air conditioners are not nearly so efficient, so to safely use them we must vent inside and have good fine dust collection.

Basement shops are a pain. Most cannot install ample isolation, airflow or even dust collection to keep from badly contaminating the home air. The only way to know if you already have a problem is to use a good particle meter. I found that the Dylos Pro meter works nearly as well as my over $8k MetOne particle counter, so strongly recommend you start your dust collection adventure by buying, renting, or borrowing one of these meters. Then you know whether or not you have a problem. Most who have been doing basement woodworking even for a very little time have problems because woodworking makes so much fine dust compared to how little it takes to harm our health. With it not going away until it gets wet, whatever me miss just builds and builds unless we clean or blow it out. Even if you stay away from the toxic, irritating or sensitizing woods, the razor sharp edges and sharp often barbed points on microscopic wood dust particles are bad news even if it takes years if not decades to cause enough harm to affect the quality of our lives.

This means we really do need good dust collection. Those firms who install large commercial dust collection systems and guarantee customer air quality found woodworking makes too much dust so we either collect it as it gets made before it spreads all over or there is zero chance of passing air quality tests because it takes so long to use exhaust fans and air cleaners to get the dust levels down enough. Fortunately, what it takes to get good fine dust collection as the dust gets made is well understood. First, with most blades, bits, cutters, and even sandpaper launching dust filled air streams at over 100 miles an hour and our dust collection systems moving air just over 40 miles an hour, we always lose unless we have good hoods that capture, direct, and deliver these air streams for collection. Even with good hoods fine dust also leaks from all around the working areas of our tools. To capture this dust before normal room air currents blow it all over we have to create a low pressure area all around the working areas of our tools. The experts found this means the sucked air being must move faster than 50 feet per minute out to a distance of over 15.25 inches in every direction. It turns out this is almost exactly three times more air than what it takes to get good chip collection, again meaning collecting what we would otherwise sweep up.

Most small shop tools need 350 CFM for good chip collection and right at 1000 CFM for good fine dust collection. Ignore small shop vendor CFM claims as these are maximums which are about double what we get in real use. In real use expect about half the vendor advertised maximums. Dust collectors and cyclones almost all use the very same type of self cleaning material handling blowers with impellers than can survive material hits and are self cleaning. Otherwise our blowers and motor bearings would soon fail. Blower technology is mature meaning if you buy the same size, type and speed blower from any of the major commercial blowers performance will be near identical. Our small shop blowers, especially many of the imports are not nearly as well made so do not perform as well. Regardless, if we check a good commercial blower table we find we need at least a 3 hp dust collector or a 4.2 to 5 hp cyclone as the minimum to move that 1000 CFM that is required for good fine dust collection.

A big enough blower is not enough. We also need ample sized ducting. Air at dust collection pressures is not much more compressible than water, meaning hardly at all. This means any restriction or undersized dust acts just like a partially closed water valve and can greatly reduce volumes. Large vacuum hose is only about 2.5" in diameter and when powered by a dust collection system only moves about 135 CFM, 4" duct only moves about 350 CFM, 5" duct only moves about 545 CFM, 6" duct only moves about 785 CFM and 7" duct 1069 CFM. Surprise, we really need full 7" diameter duct to move our 1000 CFM needed to provide good fine dust collection at most small shop stationary tools. In my designs I cheat by using oversized impellers that increase pressures enough to get 1200 CFM through a 6" diameter duct.

In addition to ducting, then we also need to deal with filters. Commercial dust collectors must be placed outside and vented outside unless they are certified as fire and explosion proof. As a result, commercial dust collection filters are rated for outdoor use. This means they are fully seasoned meaning have as much internal dust built up in the filter pores as the filter can carry though a normal machine shaking type cleaning. This extra dust makes the filters work ten to twenty times better, but with two big problems. It can easily take a typical outdoor rated filter in a small shop a year or more to fully season. Worse, even when fully seasoned, this trapped dust continues to migrate through the filters at about the same rate it is being added. The bottom line is most outdoor or typical dust collection filters freely pass the unhealthiest invisible dust for much of the filter's life. The expensive upgraded fine filter I purchased from the top rated cyclone maker was so bad that just turning on my cyclone with no woodworking spewed so much fine dust from the filter, my shop failed an EPA air quality test. You really want MERV-15 or better rated filters. What is even worse, is with the typical dust loading our very expensive fine filters only last about three months when used in full time commercial shops. This is why I came up with a cyclone design that separates off the fine filter destroying airborne dust at least five times better than its closest competitor. Many have used my cyclone for more than ten years without needing to change filters.

So, this is a major pain because most don't have the budget, power, etc. to install ample good fine dust collection. In a garage with good mask and strong vent problem this is not an issue. In a basement shop, you must isolate the air from your home and use a really good air cleaner. Forget the commercial units and strongly consider building your own. I share plans on my plans web pages for a really good air cleaner that is not too expensive. If you cannot isolate your basement air and cannot afford good dust collection, then you really should be very very careful what woods you work and use a particle meter to make sure you are not contaminating your home. I still regularly use the air cleaner I built for my garage based shop inside the home and the particle meter shows it makes a huge difference. I also had to upgrade the fine filter in our home vacuum and do a lot of very serious and expensive clean up.

As for moving the worst offenders outside, that helps, but a particle meter will show just about everything including hand tools are big time fine dust producers. I was really surprised at how much dust my razor sharp hand plane and scraper made. Remember at a microscopic level working dried wood is about the same as gluing up a bunch of glass tubes then shaping the result with an axe or rocks. My daughter built her whole desk for college outside and we had zero dust problems even with my helping. We both did wear masks. We also were not in sub zero weather…

Hope this helps…


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## wapakfred (Jul 29, 2011)

Just a note to say i'm glad to see you post here, Bill. Thanks for the insight!


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## JBrow (Nov 18, 2015)

eflanders,

I hope I am not hijacking your thread by adding to the health related discussion. I recently discovered an article by Mac Simmons entitled "Danger in the Woods" while looking for durable, well-fitting work gloves for the workshop. It discusses of a variety of potential health issues associated with working with wood, including wood dust and beyond. An interesting read for anyone who is concerned about potential immediate and/or latent wood related health issues.

While the article is informative and interesting, it includes what seems to be an authoritative chart showing 1) the type of Reaction (i.e. Irritant, Sensitizer, Pneumonitis, etc.), 2) the Site of the reaction (i.e. Skin, Eyes, Respiratory, Cardiac, and Nasal), 3) Potency rating (low to high), 4) the Source (dust, wood or leaves) and 5) the Incidence (i.e. how common the reaction is) for a variety of woods.

The article is found at:

http://www.woodworkingnetwork.com/articles/dangerinthewoods127694963.html


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## Willque (Feb 6, 2016)

I'm running a cyclone separator in my shop. Max run is only about 10-15 but there is a y in the middle of that. Does it decrease cfm, yes but it still works great for all my tools (table saw, jointer, thickness planer). I am running 4" rigid duct until I drop to my tools but my next shop will have a 6" trunk line.


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## soob (Feb 3, 2015)

I certainly believe dust collection is a good idea, but based on what I've read there seems to be little or no evidence that very fine wood dust builds up in your lungs and causes fibrosis like silicates famously do (silicosis).

The real danger seems to be asthma, at least for certain woods (especially cedar), and allergies. Also a risk of nose cancer (for certain woods, at least), but the risk was mild even for people who worked in the furniture industry back in the '60s and '70s.

Of course it can cause short-term inflammation and discomfort but that seems to be my impression of the risks of permanent damage, though I could be wrong. Here's a link to a few things I read from the CDC:

http://www.cdc.gov/niosh/pel88/wooddust.html

http://www.cdc.gov/niosh/docs/wooddust/pdfs/exposures-references.pdf


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## BillPentz (Jan 12, 2016)

> I certainly believe dust collection is a good idea, but based on what I ve read there seems to be little or no evidence that very fine wood dust builds up in your lungs and causes fibrosis like silicates famously do (silicosis).
> 
> ...
> http://www.cdc.gov/niosh/pel88/wooddust.html
> ...


Interesting, The two provided references are from 1987 and 1989, over twenty five years ago. Do a Google search on PM health risks and the volumes are nothing short of scary. Then, if you focus on the peer reviewed articles there are lots and lots of loaded risks, particularly for those who already have problems. Lots of new stuff coming out on long term damage to our circulatory systems and heart as well. Looks like fine particle material of any type is bad news. Wood with the high volumes involved is particularly unhealthy.


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## bkseitz (Oct 24, 2014)

> I certainly believe dust collection is a good idea, but based on what I ve read there seems to be little or no evidence that very fine wood dust builds up in your lungs and causes fibrosis like silicates famously do (silicosis).
> 
> The real danger seems to be asthma, at least for certain woods (especially cedar), and allergies. Also a risk of nose cancer (for certain woods, at least), but the risk was mild even for people who worked in the furniture industry back in the 60s and 70s.
> 
> ...


My Pulmonologist and Otorhinolaryngologist seem to have a different opinion and data regarding wood dust inhalation. They've expressed significant interest in what I'm doing in my shop to protect myself. Some of that is due to my asthma but not completely. They are interested in seeing the DC system, Downdraft table and Downdraft Shop Air filtration system I've been collaborating with others on.

My county was once a large forest products center: logging, milling, etc. therefore we've a large population that has been exposure to wood dust over long extended periods. I don't have the statistics on number of people injured, but I do know there are a lot of Pulmonologist and Respiratory Therapist working around the Puget Sound.

Regarding OSHA studies. The agency was prevented from further study by a court ruling agency jurisdiction: "However, in a 1985 enforcement proceeding before the Occupational Safety and Health Review Commission, wood dust was held not to be covered by the nuisance dust standard. It held that the standard only covered inorganic dusts. (12 OSHC 1785). The Agency did not regulate this substance after this decision. Consequently, OSHA had no PEL for wood dust when this generic rulemaking was undertaken."

Whether or not official scientific reports on the hazards of dust inhalation is published on this site, I like Stumpy Nubs' thoughts: At worst having a good DC system helps you have a cleaner shop to work in, but if the research shows that constant exposure over long term is a significant health hazard you've done your best to mitigate the effects.


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## soob (Feb 3, 2015)

I'm certainly receptive to being proven wrong, but I see opinion, not data.

I did read a few asides noting apparent correlations between fibrosis of unknown cause and carpentry/woodworking as an occupation-in one, which was representative, I think, it said the association with fibrosis was about four times greater for woodworking as an occupation as it was with housewife as an occupation.


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## BillPentz (Jan 12, 2016)

The 2000 U.S. census showed roughly half of the economy when home building is added, is in some way tied to woodworking. The peer reviewed medical studies show fine dust of all types is very unhealthy. This is why the EPA sets such tough indoor air quality standards. It is also why a Google search on PM health risks (PM = particle material = fine dust) shows over 100 million references. If you just stay with the peer reviewed medical references, you will see that every fine dust exposure causes a measurable decrease in respiratory capacity, some of this decrease becomes permanent, and the greater and longer the exposure the worse the damage. Wood dusts are particularly bad because woodworking creates so much fine dust compared to how little it takes to harm our health, wood dust particles are particularly nasty in terms of sharp edges and points, and wood dust contain and carry so many toxic chemicals. Bottom line the damage is still so small with each exposure that most unless they get poisoned or allergic reactions, never know they are building a problem until their later years, but most build serious problems that badly affect the quality of life and lifespan.


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