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Dust collection question...
http://www.luthiersforum.com/forum/viewtopic.php?f=10101&t=30701		 Page 1 of 2
Author:  meddlingfool [ Thu Jan 13, 2011 3:28 am ]
Post subject:  Dust collection question...
So, I need to get a good cyclone. I'm torn between Oneida and Penn State, leaning towards Penn State due to size restrictions, price and a larger filter with smaller micron collection. However I've found the salespeople to be quite offputting in various ways. I asked the P.S. guy what the free fan rating was on their systems and he pretended to mishear me 4 times in a row and then tried to change the subject. The Oneida guy was completely uninterested in dust collectors and wouldn't answer any technical questions preferring instead to tell me all about Steven Page's coke woes cause I'm from Canada too. Like I care. Point being that I was unable to establish any basis of trust after several efforts with either company. Wow, that was a rant, apologies. Here's the question. Both companies provide ducting and layout services with purchase of their machines, and both push and endorse 4" ducting as the mains. Now, Bill Pentz seems to swear up and down that 6" ducting is mandatory for the mains to maintain sufficient airflow, with 4" drops being acceptable depending on the actual air requirements of the machine being used. Should I go 6" or let them sell me 4"? Because this is such an important health issue, I really want to make sure that whatever I get is really pulling out the fine dust and not just making my shop look clean.
Thanks for any advice.
Author:  Michael Smith [ Thu Jan 13, 2011 4:26 am ]
Post subject:  Re: Dust collection question...
I just installed the Penn 3.5 horse power cyclone. I really love it. I used 6 inch main with 4" drops. It works very well. I got the remote on off switch. It is a must have. There was a fair amount of assembly required to get the system up and running. I mounted mine on the wall. I used the lightweight PVC sewer pipe for ducting. The pipe didn't cost too much but the fittings were pricey so shop around for them.
Author:  Bobc [ Thu Jan 13, 2011 7:13 am ]
Post subject:  Re: Dust collection question...
The new Grizzly catalog has a new compact cyclone.
http://www.grizzly.com/outlet/2HP-Cyclone-Dust-Collector/T23047
Author:  Ed Haney [ Thu Jan 13, 2011 9:10 am ]
Post subject:  Re: Dust collection question...
There is no "one system" that is obviously "the best" for everyone. Todd makes some very good points. Here are a couple of other points:

- in years past, a plastic duct system was cheaper than metal ducting. With the increase in oil prices over the last 4 years that has often flip flopped. I put in a metal duct system last year that was significantly cheaper than than contractor prices for PVC pipe material in my area (Houston).
- metal systems open the door for use of 7" main ducting with some special effort (but not much special effort if you have a little persistence). 7" adds significant additional air flow compared to 6" and more than 3 times a 4" system. The 7" duct system I installed was significantly cheaper than 6" PVC in my area. In other words, I got a 7" system with significantly more air flow than a 6" system and paid less for the 7"
- to use 7" you must have a system that will move enough air to keep the velocity up high enough in the duct. Most of the systems you are looking at will not do this. The Clear Vue will do this easily and the price is reasonable. It is a 5 HP system that moves some serious air. Clear Vue may be hear today and gone tomorrow as a business. Their service is good now. Future service is a factor, but is it a major factor? If you think future service is a major factor (I don't), then you are increasing your risk with Clear Vue.
- the industry is now set up around supporting 4" systems which do a good job at collecting what you can see, but do a poor job at collecting the more health-dangerous dust that is invisible.
- unless you get an air quality meter that measures the invisible dust you will NEVER KNOW what the true air quality of your shop really is. Period. Your eyes will never be able to see invisible dust. :mrgreen:

Ed
Author:  meddlingfool [ Thu Jan 13, 2011 11:12 am ]
Post subject:  Re: Dust collection question...
Michael, the 3.5 Tempest is what I have my eye on. Did yours come with the new filters?
Bob, those units are pretty tempting, but I think I need to get a future friendly (expansion) system.
Todd, the PSI now apparently ship with nanofiber filters from Clark Industries. Clark's lit looks pretty good and well tested, as for your other points I will have to do some futher examining. PSI fan curve looked realistic at least. I think...
Ed, I will look into 7" ducting for sure. Right now my primary focus is on choosing whichever machine will provide the most real life CFM...
Thanks folks
Author:  Edward Taylor [ Thu Jan 13, 2011 11:43 am ]
Post subject:  Re: Dust collection question...
I have 6" mains and runs to where there is a double or split, and 4" to single runs, its working great.

Todd Stock wrote:
Another suggestion is buy a unit with a 'drum full' sensor...cleaning out a cyclone can take close to an hour and makes a huge mess of the shop when the cyclone body, etc. is opened...2 cleanouts due to overfull drums will buy a drum sensor (at $75/hour shop rate). Also make certain the unit has a RF (not IR) remote...otherwise, you are tethered to a wall switch, resulting in a tendency to avoid the walk over to turn the DC on for quick cuts, etc. The dust from even one quick cut without the cyclone running will likely exceed the dust produced in a long sanding or cutting session with dust collection.. Do cost comparison with these two options (which are standard on some Oneidas).


This is true, I was at a friends shop and noticed the clear hose above his cyclone drum was always spinning with dust. Turned out to be a nightmare, the filter all clogged. Took a good hour, and a lot of mess, before we were back to work. I just keep a keen eye out on that clear hose on mine to make sure it always clears, and the drum is not full.
Author:  meddlingfool [ Thu Jan 13, 2011 12:30 pm ]
Post subject:  Re: Dust collection question...
Clark Industries claim a MERV rating of 15 in an independant ASHRAE 52.2 test. It's called ProTura and seems to be fairly new to the market, supposedly besting out even HEPA filters especially in terms of filter life. They also claim higher filtration of .03 - 1.0 micron.
Author:  Ed Haney [ Thu Jan 13, 2011 1:31 pm ]
Post subject:  Re: Dust collection question...
meddlingfool wrote:
...Now, Bill Pentz seems to swear up and down that 6" ducting is mandatory for the mains to maintain sufficient airflow, with 4" drops being acceptable depending on the actual air requirements of the machine being used. Should I go 6" or let them sell me 4"? Because this is such an important health issue, I really want to make sure that whatever I get is really pulling out the fine dust and not just making my shop look clean.
Thanks for any advice.


A 4" main system will not do what you stated here that want to do. It will not pull enough air at the machine. Many of our machines need more than one collection point. Therefore, many people with a 6" main will drop out with two 4" drops or a 4" and a 5" drop. (A 4" system give you one 4" drop. A 6" system works out to serve one 5" and one 3.5" drop with 3.5" being an impractical size. A 7" main works fully to to one 6" drop and one 4" drop,or one 5" and two 4" drops, or three 4" drops. So a 7" system has more flexibility and much more air flow.)

I too took the health warnings seriously. I did not want to spend the money on an air quality meter nor did I want to spend the money on an health-adequate-capacity dust collection system. But since I was serious about my health, the $2500 I spent (5 hp cyclone, metal ducts, air quality meter, hose, clamps, fittings, etc.) was/is an investment in my present and future health (and less shop cleaning). One hospital visit is more than $2500 not to mention the time and pain. This is by far my single biggest shop investment except the building itself.

I can tell if my collection points are working or not by the air quality in my shop when sawing or sanding using my air quality meter. It is a teacher as well as a warning device. There is not much choice in the market place for this purchase decision. The Dylos 1100 Pro (registers down to .5 micron) was the only cost effective choice I found. If you organized a group buy the price can drop drastically from $260 to $150 or so.

http://www.dylosproducts.com/ornodcproair.html

I can also improve the air quality in my shop by just turning on the dust collection when not sawing or sanding. The meter shows immediate quick improvement in air quality. This past weekend I added an additional dust collection point under the table trunnion of my Delta band saw. Now when I use the saw the air quality in my shop improves when I am sawing! Previously it quickly degraded when sawing. The meter shows me what works and what does not. My eyes can't be relied upon.

If I see dust I know I have a problem. If I don't see dust I don't know if I have a problem or not, unless I have the meter to tell me.

I hope you meet your objective of having a clean shop free of fine dust. It takes some work and trial and error. Don't expect much reliable help from vendors, and very few shop owners have shops free of fine dust.

Ed
Author:  meddlingfool [ Thu Jan 13, 2011 2:13 pm ]
Post subject:  Re: Dust collection question...
Thanks for the info. For me, money is not the issue, I will spend what I must. $2500? C'mon, I make that in a year, ha ha!
Author:  meddlingfool [ Thu Jan 13, 2011 4:25 pm ]
Post subject:  Re: Dust collection question...
My largest concern is my edge sander. Which IIRC Bill Pentz called for 1100cfm. The 3.5hp tempest claims a max airflow of 1700. I believe Bill also said that an average shops ducting would give 8" resistance. So if I read Penn States fan curve correctly, the machine would have around 1300 cfm at the machine. I'm not sure how to calculate specific drops in cfm depending on the drop size. But my shop is 10x12 so the longest run would be very short. The edge sander would essentially run directly into the collector. The only other tools I have are a contractor saw and a bandsaw. I work alone so no need for multiple ports drops open
Author:  Chas Freeborn [ Thu Jan 13, 2011 4:43 pm ]
Post subject:  Re: Dust collection question...
I've got the 2 hp Oneida (Dust Gorilla). It has been quite adequate for my 800sf shop with table saw, 24" drum sander, edge sander, planer,etc.
Don't know why you had trouble with their customer service - my experience has been very good with them.
Be aware that cyclone systems are much more efficient than conventional, so less hp is needed.
-C
Author:  SteveSmith [ Thu Jan 13, 2011 5:35 pm ]
Post subject:  Re: Dust collection question...
Chas Freeborn wrote:
I've got the 2 hp Oneida (Dust Gorilla). It has been quite adequate for my 800sf shop with table saw, 24" drum sander, edge sander, planer,etc.
Don't know why you had trouble with their customer service - my experience has been very good with them.
Be aware that cyclone systems are much more efficient than conventional, so less hp is needed.
-C


+1
I've had great service from Oneida. Mine fits under an 8' ceiling and uses a 7" main duct. Well worth the space in my small shop.
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Author:  meddlingfool [ Thu Jan 13, 2011 5:44 pm ]
Post subject:  Re: Dust collection question...
Have either of you tested air quality with your 2hp machines? If Bill Pentz is right and an average shop ducting will add 8" static pressure, according to the fan curves you guys are only drawing about 600 cfm at the machine, which is not nearly enough for ME recommendations. But perhaps I am not reading things right...
Author:  Kent Chasson [ Thu Jan 13, 2011 9:30 pm ]
Post subject:  Re: Dust collection question...
This chart seems to be the standard for calculating static pressure. http://www.woodweb.com/knowledge_base/_ ... _guide.pdf

Todd, why can't you get more than 400 cfm through a 4" duct? I've heard that before but I've never heard an explanation. Don't you plug the SP into the fan curve to get the CFM? According to the woodweb chart, 100' of 4" duct generates about 7" of SP at 4000 ft/mn. The Oneida 3 HP Dust Gorilla is rated to pull more than 1100 cfm at 7" SP. What am I missing?
Author:  meddlingfool [ Thu Jan 13, 2011 9:51 pm ]
Post subject:  Re: Dust collection question...
So Todd, are you saying that even with 7" ducting a 5hp blower rated at 1800 cfm will still only provide 1200 cfm max at the machine? That's enough for my needs I guess but I'd rather have a bit of extra suck.
Author:  meddlingfool [ Thu Jan 13, 2011 11:35 pm ]
Post subject:  Re: Dust collection question...
So what do you do to get more CFM? By and large 5hp seems to be the cutoff before jumping into an industrial type setup which is impractical for a little basement shop. I'd have thought a 3.5 machine would have been enough, but for 200$ I can get the 5hp, it's the same physical size...
Author:  Ed Haney [ Thu Jan 13, 2011 11:40 pm ]
Post subject:  Re: Dust collection question...
meddlingfool wrote:
So Todd, are you saying that even with 7" ducting a 5hp blower rated at 1800 cfm will still only provide 1200 cfm max at the machine? That's enough for my needs I guess but I'd rather have a bit of extra suck.


Yes, Todd's numbers are correct. You can see what I was saying about the advantage of a 7" main which gives you the ability to handle anything in a one man shop with enough cushion take care of dirty filters, leaks, hose runs (hose has much more pressure loss than pipe), real life, etc. But with 7", some extra HP is needed and 3HP can become borderline. Bill P. has a good Excel spreadsheet free on his site. I used it to calculate SP etc. to help make decisions. Have you used it or something like it?
Author:  meddlingfool [ Thu Jan 13, 2011 11:55 pm ]
Post subject:  Re: Dust collection question...
No, not yet. My computer won't let me use it. I'm already thinking I should look for 5 hp. I'd like something that I can add machines too. Eventually I'll have a jointer and a thickness sander.
Author:  Chas Freeborn [ Fri Jan 14, 2011 12:01 am ]
Post subject:  Re: Dust collection question...
Okay everybody, put down the calculators for a minute.... a 10 x 12 shop, that's basically a small bedroom and your maximum duct run is what, 6 feet?... running 1 machine at a time? You've got to be kidding. The 2 hp Oneida will pull your toupee off at that load. Quite frankly, I doubt it will even develop it's full cfm choked down to a single 4" machine hook up.

For such a small shop, get one of the pleated filter 1.5 hp Jet type units, keep the filter clean and call it done. You're way over engineering this...

Concentrate on positioning the shroud(s) to maximize it's efficiency. Here is how I re-worked the collector point on my edge sander. I added a second pick up in front to catch the overspray the factory hook up let get by:
Author:  Mark Fogleman [ Fri Jan 14, 2011 12:26 am ]
Post subject:  Re: Dust collection question...
meddlingfool wrote:
So what do you do to get more CFM?


If you've minimized resistance in the piping you have three choices: A bigger fan and motor, add extra filter area or straight pipe the exhaust outside minus the filter. Make sure you have clean make up air coming in the opposite end of the shop and no gas furnaces or hot water heaters in your shop if you go the straight pipe route.

(wow...a Dust Collection and a SawStop thread in 2 days! Eat Drink )
Author:  meddlingfool [ Fri Jan 14, 2011 12:50 am ]
Post subject:  Re: Dust collection question...
Well it's a 10x12 shop today, but hey I feel optomistic so I want to plan ahead.
Chas, have you read Bill Pentz's site?
Author:  SteveSmith [ Fri Jan 14, 2011 10:46 pm ]
Post subject:  Re: Dust collection question...
Even in my small shop, I'll stick with my 2 hp Oneida, thanks. I took the time to do the engineering and ran the numbers when I installed it and designed the ductwork. I wouldn't want anything smaller for the hazardous dust you can't see.

Just my 2 cents.
Author:  Ed Haney [ Fri Jan 14, 2011 11:55 pm ]
Post subject:  Re: Dust collection question...
Certainly shop size is a factor for sizing a dust collection system, but may not always be the deciding factor. Other factors are the number of machines that run simultaneously and the type of machines.

For my small one-man shop (8'x20') I was only concerned about running one machine at a time (not unusual). The key factor was the worst case machine requiring the most air (not unusual). This is a table saw (800 to 1000CFM). My belt sander, miter saw and band saw require nearly the same. I decided that a real 1000CFM would be my minimum target capacity for a system with 4000FPM minimum duct velocity. This is in line with Bill Pentz's recommendations. So my shop size was not the key factor, nut I paid close attention to my dust collector's fan curve considering SP loss for actual ducting size and lenght and loss for filters, etc.

One 4" duct will supply about 350 to 400CFM. Splitting that one 4" with a 'Y' into two 4" lines will give you about 175 to 200CFM for each of these. The work of Bill Pentz and others indicate that this would not be effective for healthful dust collection. With enough system capacity, instead of using a 'Y', taking both 4" connections back to the main duct would result in both having 350 to 400CFM instead of half that.
Author:  meddlingfool [ Sat Jan 15, 2011 12:54 am ]
Post subject:  Re: Dust collection question...
True that!
I was looking at the 3.5 Penn State, but I think I'll up it to 5hp for another 2 bones. I'm attracted to the doubled filters PSI has. If someone can point out a reason why these systems are inferior to something else I would appreciate the input. I've done a lot of reading but much of it is over my head. I need to act soon as I'm noticing a slight but distinct reaction every time I enter my shop, and a noticable drop in respiratory fitness. Maybe just from getting older but....
Author:  Michael Smith [ Sat Jan 15, 2011 3:56 am ]
Post subject:  Re: Dust collection question...
I didn't go with the 5 hp due to the electricity draw and more money. You figure you maybe have a sander going, maybe a space heater, kick on the 3HP tablesaw and the dust collector at the same time and that is a pretty good draw. For me the 3.5 has proved to be plenty. My shop is only about a thousand square feet. I keep my table saw gate open at all times and have plenty for any other machine I use. My band saw has two 4 inch dust ports so I ran a 6" drop and gate for it then Y ed to each port.
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