Measuring Dust Collection Airflow | Woodworking
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- Опубликовано: 27 фев 2019
- What makes an effective dust collection system? It's important to choose the right dust collector, but it's equally important to choose the right hose size, hose type, and fittings to get the most out of your system. In this video, you'll learn how airflow is effected by the hose size, hose length, fittings, and layout of your dust collection system. We measure airflow in different situations to demonstrate how each component effects the effectiveness of your workshop dust collection system.
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Wow you broke this down to 3rd grade level. At first I was like, "Oh man, here we go. He's gonna put on his white lab coat and talk about the Bernoulli principle with fluid dynamic equations." But this was succinct, accurate and blessedly math free! Thank you!
Thank you for inspiring the next generation of learners, perfect for our homeschool as we plan and build a dust collection system.
Best video on dust extraction I've seen on the web. Thank you.
The man's wearing flannel. He knows what's up, im definitely watching this entire video lol. Thanks for the info very helpful
I’d bet my house that he’s standing in a pair of New Balance sneakers.
The Bill Nye of woodworking.
Nice job, as a retired mechanical engineer I was impressed with the way you showed the principles. Now if you can just solve the miter saw’s problem of miserably poor dust collection.
I've heard festool has done the best in the industry for dust collection on the miter saw, with their kapex miter saw.
@@joshyingling As a woodworker and an engineer, I solved the miter saw problem, at least in my shop. Here is my solution ruclips.net/video/SBcdS1ACEQ0/видео.html (sorry for the video, is old and it's not the best video I produced). And I'm currently editing a video about the science under the the diy dust collection systems, to be published this saturday :)
I feel that you did an excellent job of explaining the basic mechanics of air flowing through a pipe, but completely neglected to say how it applies to this situation!
Should one use a larger diameter system of ductwork, only reducing as needed size at the tool? Can diameter be increased/decreased without significant losses? Is there an ideal diameter of the inlet for chip capture based on CFM or horsepower of the system? (duct length and complexity not withstanding). Is there an ideal volume/pressure ratio for chip capture? For airborne dust capture? Is there different CMF/HP/Diameter/airspeed for dust extraction VS chip capturing? How do such systems differ?
Great comment, I have the same questions and wish they were addressed.
I’m a nail tech (nail salon owner) making a dust collector instead of spending thousands on a 110cfm fan and this helped so much! Thank you!
thankfully nail techs don't have to deal with as much dust as woodworking however acrylic dust does need to be controlle.d
Thousands on a 110 cfm fan? 😄
Totally distracted by the map of Budapest. My wife and I were there four years ago - what a great city full of wonderful people, and incredible history!
And thanks for this video; I'm setting up my first real dust collection system. Medium sized shop, voltage limited to 120V, so efficiency will be crucial.
Fantastic video and description of air handling! Learned a bit and increased my overall understanding. Thanks for posting this video. Great stuff
Kedves Sándor! Nagyon jó videó lett, köszönjük szépen!
This is amazing, It answered so many questions.
very good video, informative and very well presented, thanks for posting from Garry in the UK
Clear and concise - thank you. Great fundamental information.
instablaster
Excellent tutorial. Thanks for the information. I’m setting up a shop and this has been very helpful. 👍👍🇨🇦
Brilliant and timely. Many thanks from Ottawa, Canada.
Thank you for coprehensive coverage of the subject! Even i understood most of it 😀
You have been an inspiration to me.
I read your book three times. Actually took two classes at 2nd year HVAC engineering level. I have two Ph.D.s and a law degree (no joke). I made a ton of money on tech stocks so I allocated $3M to build a sawmill, dry kiln, millworks and all the associated shops. 5500 sqft. Yup, the go big before you die approach.
But, I still ended up spending >$40K (2000 dollars) on engineering to get the dust systems right.
This stuff doesn’t scale from the 2 car garage shop (which is what I had for 25 years).
With the advent of the mega-shop builds that RUclips seems to suggest, people need to invest in experts. Or just try and self-insure your fire risk •••
Thanks for the science lesson, well done. Best explanation I’ve seen so far… and there’s lots on you tube. This alone earned my sub.
Thank you kindly for the extraordinarily simple explanation.
Howdy Sandor!!! I just happened upon this video when I was wanting to build my own cyclone bucket! It was good to see you at the beach in S.C. last year!!! Pamela
Extremely helpful. Thanks
Thank you for such a great video. Your explanation helped me a lot.
This is a ruddy brilliant video. I feel I much better understand what I'm up against. Dust collection has been a bit of a thorn (or perhaps a splinter) in my side as I try and figure out all the fittings and hoses and layout. This adds another layer of complexity, but a whole lot of understanding. Thank you!
Excellent content, just what I was out looking for, thanks a lot 🙏👍👍
Most helpful video in understanding dust collection. Thanks
Excellent vid. Many thanks, from New Zealand
Very simple explanation..thanks..
Great video. Gonna help me get control of my dust. By the way, since this is a video on dust, those blinds could use a good dusting.
Köszi, "Sanyi bácsi", for the explanatory video, this was just the topic that I needed to start with a second hand shop vac I just got from a friend! I got stalled in the first 2 seconds by the map on your wall, but it made me instantly google the author! Keep up the good work!
Every time a popular topic 👍🏼
Thanks, this was indeed super helpful.
Excellent video, thank you so much.
Thanks! This was an outstanding presentation.
Great video! Beat dust collection video I have seen!
Great video! Thanks for posting!!
Great video, thank you!
The people that are building dust collection systems using Shop vac's and 2" PVC ducting with all kinds of 90's and T's really need to see this video!. Especially when they are hooking up to equipment that have a 4" dust ports on them. Most woodworking equipment have rated or recommended CFM requirements. Most if not all shop vacs will never meet this requirement especially after all of the pipe, 90's and T's are in place. For the price of a good shop vac, the dust system you are using can be had and would far better be suited for almost any basic DIY'er wood working tool.
Very great explanation. Thanks.
very detailed and helpful...thanx
Wow! Really helpful information. Looks like I’ll need to watch it another time or two before really it sinks in, though. I was kind of left scratching my head at the end of it - wondering how to solve this problem on a budget. Or better yet… if it’s even
solvable on a budget. Too helpful a video not to subscribe!
Thanks a lot.
Awesome man thankyou so much
Thanks needing info great video
Great video! Thank you so much for taking the time to help educate us novice woodworkers! Do you have any videos that explain how to handle static electricity in your dust collection system? I just purchased a desktop CNC and the static from my shop vac is driving me crazy!
In my opinion (industrial background) static conductive vent/duct/materials grounded on both ends is the best way to address, but using static dissipative vent/duct materials should also work just fine for what we do. Flexaust is one vendor that makes both types, and is who I am going with as I am building my new home shop.
very inspiring explanation
had to replay the first 2 seconds over and over so i could figure out this guys name. Conclusion? No idea, but it's the best name ever, haha! Great info!!
Sandor Nagyszalanczy. I have his book, which is great! Never knew how to pronounce his name. Do now. 🙂
As a Student in a Prof. Bachelor WoodTechnology I can really say this a fantastic way to explain the basics of dust collection. Great Work!
Your book is a classic.
Watched to the end. Walked away with the notion that I need a 3 phase 25 Hp system with 10 inch metal or plastic pipes. A follow up video is needed to move from the abstract / theoretical to the concrete / real world application.
Absolutely agree, I'm thinking that a larger duct then stepped down at the tool will work the best? I compare it to the water cannons they used to use to strip dirt in mines????
@@patrickmeeuwissen9331 I wouldn't suggest your method: high air velocity at the tool, seems great! But the air slows down at the larger duct, which means that some heavy particles would not be carried away anymore. Resulting in a clogged system.
@ @@StephenBiebuyck richtig, aber zunächst müssen die wegfliegenden Späne oder Stäube aufgesogen werden. Das gelingt nur mit höherer Geschwindigkeit, d.h. einer feineren Düse. Die Stücke dürfen aber nicht zu groß werden.
Agreed!!!
Keeping it simple thus keeps it at maximum effectiveness.
great video!
5:01: Nope
Given the same *volume*, the air flowing through a narrow hose will naturally travel at a higher speed than through a wider hose. Volume however wasn't the constraint stated by the presenter, but rather *pressure*. All other things being equal, with the same pressure, the speed will be the same in both hoses.
But let's be clear -- the same dust collector, powered by the same motor at the same electrical input won't be exerting the same (negative) pressure on the wider hose and thus the air velocity will be lower. That's the point to remember.
The reason the air comes out of the straw at a higher velocity is that a human can't generate the same high pressure in the wider tube -- you're off the human 'pump curve'.
Fluid dynamics are lovely, but not always lending to simply explanations.
Thanks a lot for your information, really important. Can you speak about the "gates" in a dust colector system?
thank you
I read the last edition of Woodshop Dust Control and learned a lot about, well, a lot. I really appreciate how you covered so many facets of woodshop dust and shavings and ways we can protect ourselves and our woodworking environments. I struggled with some of the concepts, though, and found this video to be very good at explaining the factors into overall dust collection airflow. I hope that you plan to release more videos related to dust control, including various equipment, differences between a large collector vs a shop vac, air filtration systems, and personal protective equipment (PPE). Also, I often wonder how much misinformation is out here on RUclips and on the Internet, so perhaps also clear up some of the confusion if/when you release videos.
Also, do you plan on updating Woodshop Dust Control? The copy I read was from the library, and I'm interested in buying a copy for reference. Thanks for the information!
Madtown Brian
Brian I’m sure Sandor won’t post a link to his book but I will. If the link doesn’t work just go to Amazon and search for “dust control book” and his book will come up in the que. The book also comes with a dvd. It was a very informative book and the dvd was a bonus.
www.amazon.com/Dust-Control-Simple-Step-Step/dp/1600852483/ref=mp_s_a_1_3?keywords=dust+control+book&qid=1574717100&sr=8-3
Ron
Wow!! I wish I could tell you how many people in Facebook groups for hobby level CNC router's and general woodworking group that I have preached dust collection principles to. 100% of my knowledge came from your book.
I am designing my 2nd dust collection system right now and I have to say THANK YOU because your book taught me so much.
Clinton Caraway would you recommend 6” or 4” pipe? I have 1.5hp dust collector
@@pharaohacura3618 look at your dust collector's inlet.... not the splitter but the actual piece right before the impeller. Most likely it's a 6". If so run the 6" as far as possible and reduce to 4" for drop downs to each machine.
Clinton Caraway to be honest after i saw the price of 6” pipe, i opted out for the 4”...Lowe’s had ‘buy 10 get 20% off’ , lol...
Thanks for sharing that
Answered my questions. To move large quantities go fo 4” pipe, smaller quantities go for 2.25”. (Bigger pipe requires bigger everything) and don’t bother with a 40’ hose unless you have a lot of power.
Soooo, what to use?
Nice to see Sandor still in the woodworking business and still teaching us in a way that we can understand and apply to our shops.
I think this video gives a great foundational understanding of dust collection, but I feel the need to clarify some things you said about the duct or hose size.
Air velocity is absolutely relevant when it comes to friction inside the ducting or hose, but only air volume matters for capturing dust before it escapes the localized partial vacuum near the dust collection intake. I think the example of blowing through a straw is misleading because it may leave people with the false understanding that the increased velocity inside a smaller tube will capture more dust. Keep in mind that suction is all about the difference in air pressure, and suction does not have velocity. When you blow air through a straw, it can move more sawdust because the fast moving air will come into contact with more still air, and cause a greater volume of air to move as it trades velocity for volume. The same does not happen with suction. For any fan that can move a certain volume of air, the dust that is pushed into the vacuum from room pressure will be the same regardless of the hose size, if you aren't accounting for friction. When we account for friction, the bigger hose will perform better. Your example with the shopvac using a larger 4" hose attached is misleading because even though the velocity in the hose is indeed lower and you are seeing fewer chips sucked in, these are not related. The reason fewer chips are sucked in is the same thing that happens inside a vent hood or any dust collector attachment. Your demonstration with the larger tube sucking in fewer chips is a result of it drawing in more surrounding air and less air containing dust, which isn't a factor when your hose is connected to a tool's duct collection port or a vacuum attachment. What happens in the duct or tube after intake doesn't matter (except for losses due to friction or blockage). What matters is the volume of air you are moving into the tube, and efficiency is primarily dictated by the hood's ability to draw more air containing dust than surrounding air without dust.
To summarize what I'm trying to clarify, your fan's CFM rating matters a lot more than hose or duct size, and a bigger hose is always better when connected to the same tool or vacuum hood.
But you were spot on with all the talk about losses due to friction and general recommendation to use at little flex tubing as possible.
Do you have recommendations for reading, videos, or websites we can go to for additional information?
Great video with a simple explanation of the principles. You might want to add along with friction comes static electricity and you need to add a grounding System.
As important as that is, it doesn't fall under the remit of the title.
That’s old woodworkers myth
Now that you’re done testing, I’ll take the PM off your hands. Lol. Good vid.
How do you address the static electricity build up? Some forks wrap a copper wire to a grown source
Very good video in explaining the fluid dynamics of air handling. I was very interested in the changes of volume and airspeed between a 4" and a 2" hose. so many of my tools have 2" ports and I'm currently installing 30 feet of 4" PVC piping with three sanitary T's and blast gates unto a WEN 1.5 HP cyclone dust collector 650 CFM. All turns will have two 45 deg together reducing friction with a total of 4 bends. All will be reduced to a 2" hose to connect to each machine. I'm now wondering if I'm making a big costly mistake? I guess I'll find out once it's all installed.
I think I am getting the idea. So the more air you can move the better.
Thanks for breaking down the physics much appreciated. I am going to put my above 150 IQ on this and dust free my shop.
Wish you would have done the readings on the shop vac
What unit works best with low decibel levels?
Ribs of the flex hose are causing turbulence which creates significantly more resistance to the air flow than surface friction.
I have a Rockler Dust Right 650. It has a 4 “ inch hose. My Tools Dewalt 7845 Table Saw has a 2.5 inch dust port. I also have a Ryobi 12” inch Miter Saw with 1.25 inch dust port. I’m new to Woodworking and trying to figure out the best way to set up dust collection. I would like to run a Y fitting from the DC. So I could run a 4 inch hose with 2.5 inch reducer for the Table Saw and a 4 inch hose with a 1.25 inch reducer to the Miter Saw. But I know if it will work right
Can you run ductwork under a raised floor? Then up to the cyclone? Most setups I've seen are overhead.
You can, and that may allow you to design straighter runs with smooth pipe & less turns, thus reducing your friction. Just keep in mind that without proper velocity, chips may collect in the ductwork, so configure your system to allow for periodic access.
A very clear way of explaining this! Im interested in the pros and cons of mixing different diameters. Is it best to stick with one at all times? I bought a "shop vac" (not the brand though) and it has a 32mm diameter. Is there any point in using a larger diameter for a longer path? (when the machine is in the other end of the shop for instance).
What you can do to increase velocity farther down the pipeline is to decrease the radius after a certain point. This will not increase CFM but can be useful for smaller tools that require more velocity and less CFM.
Very good information. Please mention in another video if possible, the static electricity generated by the dust and how to deal with it. Thanks a lot.
I bought the harbor freight 2hp dust collector which is a 4” inlet. I want to add a Oneida super duty dust collector and make a 2 stage. They offer 4”,5”,&6” sized super dust deputies. How do I do the math to know which is the most efficient????
I'm sure there are apps for duct sizing, but here is the old school way and it works very well for round ducting "Trane TD1 Ductulator with Sleeve, Duct Sizing Calculator
". They are about $15. A general rule of thumb for dust movement is to try to keep air flow at or over 4,000scfm. Slower it sticks to the walls of pipes. Too fast though and it can generate heat from air friction. Once you take the collector's rated capability and line it up with a pipe diameter on the Ductulator chart that results close to 4,000scfm, it will probably be a good place to start. Use long sweep elbows if possible.
I'm not trying to be funny..but does anybody else think he sounds like Brent spiner?..
Robert Mcdonald I was thinking Owen Wilson
@@jrichardson6 I can hear that too.
Well, now you mention it, he did give us quite a bit of Data...... 🤣
No LORE, Don't do it!
Oh absolutely. Check out the way he says the word "performance" at 1:29.
Not to mention the static electricity caused as the air flows through any convayence.
...and? What do I use then?
This video doesn't really give any answers.
If one ignores the complexity of the system - and is limited to the same dust collector (not knowing its performance):
Is it better to have a long wide internally smooth hose - or a long narrow internally smooth hose?
Also, what about combination of hose diameters?
Is it better to run a wide duct-work, the narrow them down as the duct gets longer?
Yes, use wide, smooth duct-work as much as possible, then narrow at the collection point.
@@hatsix If I want to extend (make longer) original pipe of vacuum cleaner, should i use narower pipe?
Hi, i saw your video and I have a question to ask about the dust collection system that i'll be bulding for my very small bedroom shop.
I want no costly mistakes.
Ok, my Shop-Vac is a 6.5HP with a 2 1/2" hose attachment. Now here's my question. Should I stick to the 2 1/2" piping or should I use larger PVC pipping like 3 or 4"? Will the larger hose give me more suction towards chips and dust, or it would be the exact same as if I would use a 2 1/2" pipping?
And 2nd question. I know that flexible hose is not a good idea, cause the ridges cause loss of suction.
But I still need to ask. If I'd use flexible hose, BUT at the exact length between each connectors, no bending of it, fairly tight fit, would the loss of suction still be the same issue, cause of the ridges? Or it could do the job? OR should I stick to PVC?
Please let me know. I'd greatly appreciate your help. Thanks
do they make smooth wall flex hose?
What cfm machine are you using for the demonstration
Ironic that you can see dust all over the venetian blinds behind him. Clearly his dust collection is not trapping the fine particles.
how much noise can i stand to get the job done?
So, what your saying is 4" is bigger than 2"?
Yes, 4 times.
8:52 DORA THE EXPLORER MIXED-UP SEASONS
Hello, I was hoping someone could help me with an issue I'm having with my 4inch dust collector. Is anyone available?
Why doesnt anyone combine vacuum plus blowing to make a semi closed system? Because it doesnt help?
I have the Harbor Freight system with 4” PVC. All machines in a row (split the two car garage in half) Air flow is ok but it’s hooked up with 120 service. What’s the benefit of upping to 220?
If motor rating (HP-Speed) is same and blower (Dia- width-pitch) is the same the only benefit would be lower amperage on electric service and a cooler running motor.
Thank you for your answer and quick reply! Happy woodworking.
what causes pressure losses?
There can be several causes. Fittings that are not tight or hoses that have holes, runs of tubing that are too long, collectors that are over full of sawdust or chips.
It is too substantial a question to answer here. Sandor’s book is a great place to find all the answers and the solutions to the problem.
why does a long hose cause pressure losses?
@@ScreamingEagleFTW more friction along the longer length of the hose
I used to sell large dust collector and you should ground (connect to the ground not the negative in a panel box or a ground rod put in the earth) the duct work as the dust moves through creates static electricity which has been known to cause fires.
dear god, the size of rthat powermatic unit is absurd!
duuuuuuuuuuuuude
Does anyone else see the dust collecting on his window blinds?
Even going from 3” to 4” you nearly double the volume.
If only I could spell your name, I could find your book.
My friend, this is an amazing video, however I must inform you of something. AT TIMES YOU SOUND EXACTLY LIKE BRENT SPINER?! Everyone close your eyes and imagine Commander Data speaking. It's uncanny.
Anyone who can't figure out that a 4" hose can carry 4x the volume of a 2" hose (or more given friction considerations) didn't get much out of this video.
Unless you get a whole room that is a vacuum chamber you will never solve miter saw dust collection
You can fill the room with water and while most particles go to the surface you could have some microbes eat the rest. Problem solved..? (Yes, im tired)
Just go to low earth orbit, or visit your local hyperloop.
a complete lack of conclusion????
I assume this sort and level of explanation is aimed at Americans. They seem to need everything aimed at 5 years old children.
This is more has to do with fluid dynamics than woodworking 😅