Upgrading dust collection; could use some help

[Mark Hepburn]

Hi Everyone.

So, over the holidays I had a little spare time and started cleaning the shop in earnest. It's really two rooms; one is a "clean" or assembly room and the other is what I'm talking about here, which is where all the tools are. Pic posted.

So I realized as I was cleaning the pounds of fine dust that a) my dust collector isn't cutting it and, b) I quit smoking for a reason and don't want to swap one carcinogen for another

Anyway, that led to my researching until my eyes glazed over and my head hurt. Bill Pentz would wash his hands in exasperation because, although I've read and read, the practical application isn't sinking in. What has, however, is this: I'm ditching what I have and redoing. Currently I have a Grizzly cyclone with 4" PVC piping and flex hose machine couplings; a couple of Shop Fox fine particle filters and a larger Shop Fox hanging air cleaner. That I'm keeping. The smaller ones I moved to where I paint.

I think that, for me, I'd like to have a system that simply exhausts the fines to the outside and that captures the chunkier stuff before it gets to the impeller. In other words, really no filtering. The nearest neighbor is over 140 yards away on any side and there's nobody to be bothered by the particulate. Also, I'm out in an area where there are no ordinances against the discharge. And, the shop, although connected to the house, is not conditioned and I would seal the doors to prevent pulling conditioned air out of the house. A make up air vent in the outside wall would seem to do the job; I'm in south Louisiana and temps are fine year-round.

I want to go up to 5 hp but single phase, with 6" or possibly 8" main piping with reducers only at the machines that are ported for 4". So I'd put a reducer on the end of each drop to minimize any 4" bottlenecks. Also, I will be investing in automatic blast gates and using metal duct.

I drew up a rough plan showing a rough idea. I did forget to include a floor sweep in the drawing but would probably like to have one at each end of the shop.

Any opinion, expertise, or practical assistance would be most appreciated. For example, WHERE do I find a large impeller and housing, etc. Bill Pentz' site points to electricmotorwarehouse.com, which has a very nice Leeson for this purpose. I have buddies that do electrical for a living so the wiring isn't an issue. For me, it's gathering the parts and knowing how to proceed to assemble, etc.

Thanks!

 

[Dean Center]

Marc,
I have two thoughts.

First, before you buy anything new, why don't you hook the exhaust on the collector you have now to the outside and see what happens? The decreased resistance might make enough difference to solve your problem at no cost.

Second, PVC pipe as ducting has a lot of static electricity and a smallish internal diameter. You could try replacing the PVC with metal ducting to reduce the resistance to airflow some, and improve your through put. It might make enough difference to solve the problem, at modest cost.

BTW, wood dust probably won't give you cancer. It would be more likely to cause chronic bronchitis and emphysema, neither of which is a good thing to have.

 

[Raul McCai]

Anyway, that led to my researching until my eyes glazed over and my head hurt. Bill Pentz would wash his hands in exasperation because, although I've read and read, the practical application isn't sinking in. What has, however, is this: I'm ditching what I have and redoing.

Pentz is about right.

If you haven't been to Felder's site and taken a good gander at the RL line you might consider looking at it. Nothing comes close. They are not cheap at about $4 – 5 K entry price but they are the only ones that do what they say they will do,
http://www.felderusa.com/us-us/products/clean-air-dust-extractors.html

Any opinion, expertise, or practical assistance would be most appreciated. For example, WHERE do I find a large impeller and housing, etc. Bill Pentz' site points to electricmotorwarehouse.com, which has a very nice Leeson for this purpose. I have buddies that do electrical for a living so the wiring isn't an issue. For me, it's gathering the parts and knowing how to proceed to assemble, etc.

4" PVC piping and flex hose machine couplings;

About Ducting: No insurance company will cover a fire if their agents can claim that it may have been started by a spark in the Non-Metallic Dust Collection lines. I don’t intend to enter a dialog about the merits of this particular concern. The issue I want to point out is that Insurance companies won’t cover it if it is not metal and grounded. They won’t cover it if there is a grounding wire or metallic paint or anything else. They will only bless metal ducting with a ground strap.

As to an impeller.
Oh my~!!
Even Onida is using a plastic impeller that blows up when it hits a chunk.
There is no source that I’ve found ( and I’ve looked and looked) for a decent impeller.

I was planning on building my own because of the ceiling height problem with most of the Cyclone units like Onida and ClearVue. However, I’ve decided to wait till I can get an RL.

 

[DanRoscigno]

I just installed a clearvue cv1800. I am using the Wynn cartridge filters that they sell, but venting to the outside is better. I would look at this one:

http://www.clearvuecyclones.com/cv1800-series/25-cv1800-lh-single-phase-no-filters.html

See Stumpy Nubs' web site for a discount:

http://www.stumpynubs.com/dust.html

Discount code is nubs5

Since you can get the wiring done yourself, don't spend the $250 on the optional electrical box, it is something you can do for about $25 yourself.

6" Thin Wall Gravity Feed Sewer and Drain is cheap, easy, and works fine.

 

[Gerald Lawrence]

Your plan sounds good. The filter may be part of the problem. I switched to a pleated filter and increased pull considerably. Also someone here did a write up on putting a wok (yes cooking ) in the machine to create a vortex like Jet does. I will give you details if you need, This also helped pull dust into lower bag and decrease the fines in my vacum room. Oh, I have mine in the attic in a sealed room with a filter on the return air.
I too wish I had the 6 inch return, just do not do enough flat work to justify the cost and climbing.
Having fun back in LA in NO for the Sugar tomorrow.

 

[Bill Boehme]

I grew up in Houston and have been to south Louisiana so I know that "static electricity" is a foreign word because the air almost always fully saturated sometimes even more than 100% (yes, it is possible to have supersaturated air). However, just to avoid the remote possibility a a tiny electrostatic shock there is conductive PVC flex hose for the short runs from the DC system metal duct drop to machine exhaust port. If you want better dust collection at the machines, more horsepower isn't going to help a lot until you improve the machine dust collection. Most shop machines do a dismal job of this. SawStop is an exception ... tyey do an outstanding job of collecting dust. Almost all bandsaws have a DC port that is hardly more than decoration. It doesn't take much ingenuity to make a lot of improvement in the way that they work. I have a Delta stationary planer and Delta stationary jointer... they are OK when it comes to dust collection, but the bottom line is that there will still be plenty of dust that you can't capture with a DC system.

I have some of the 2.5" conductive plastic hose on my shop vac. It's great to not get those defibrillating shocks.

 

[Ron Rutter]

I built a cyclone based on Bill Pentz design info for our seniors WW shop.This was tied into a 3HP DC. I incorporated a drop box & made the cyclone outlet 10" instead of 8" dia. After 2 years there was only 2" of material in the DC bags. BUT, you have to remember to MT the drop box!!This also keeps larger chunks out of the impeller.
If you are not paying to heat the air discharging to atmosphere is great otherwise the air passing through the DC just returns & does contain fines - if you have no neighbors to complain!! You can put the DC in a closed room with a filter bank to clean the returning air.
In addition you could install an air cleaner. No matter what we do there are still the dangerous fines floating around.

Protect yourselves folks. I am probably going to have to quit turning because of lung problems & I have about 500 blanks of 7 or 8 different woods that I was planning on playing with....
By the way I feel the ramp in Bill's cyclone is the real secret.

Ron.

 

[Mark Hepburn]

Marc,
I have two thoughts.

First, before you buy anything new, why don't you hook the exhaust on the collector you have now to the outside and see what happens? The decreased resistance might make enough difference to solve your problem at no cost.

Second, PVC pipe as ducting has a lot of static electricity and a smallish internal diameter. You could try replacing the PVC with metal ducting to reduce the resistance to airflow some, and improve your through put. It might make enough difference to solve the problem, at modest cost.

BTW, wood dust probably won't give you cancer. It would be more likely to cause chronic bronchitis and emphysema, neither of which is a good thing to have.

Dean, that's a good idea and I think that I'll try it out. If I sell the thing I'm sure to be losing a significant amount - if I can sell it. And I should have mentioned that I do intend to ditch all the plastic and purchase metal duct, blast gates, etc. That is a certainty. Another possibility is to keep that unit, duct outside and set it up for part of the tools - for example, just the lathes maybe.

 

[Mark Hepburn]

Pentz is about right.

If you haven't been to Felder's site and taken a good gander at the RL line you might consider looking at it. Nothing comes close. They are not cheap at about $4 – 5 K entry price but they are the only ones that do what they say they will do,
http://www.felderusa.com/us-us/products/clean-air-dust-extractors.html






About Ducting: No insurance company will cover a fire if their agents can claim that it may have been started by a spark in the Non-Metallic Dust Collection lines. I don’t intend to enter a dialog about the merits of this particular concern. The issue I want to point out is that Insurance companies won’t cover it if it is not metal and grounded. They won’t cover it if there is a grounding wire or metallic paint or anything else. They will only bless metal ducting with a ground strap.

As to an impeller.
Oh my~!!
Even Onida is using a plastic impeller that blows up when it hits a chunk.
There is no source that I’ve found ( and I’ve looked and looked) for a decent impeller.

I was planning on building my own because of the ceiling height problem with most of the Cyclone units like Onida and ClearVue. However, I’ve decided to wait till I can get an RL.

Raul,


Just looked at the RL products. Talk about tool junkie candy! Reminds me of when I used to get motorcycle fever every spring and just HAD to buy another one.

If I got the RL 300 it'd probably suck my dog up into the ducts (she hangs out in the shop with me; all 9 lbs).

So no argument with you on the ducting. One of my significant take-aways from Bill Pentz is quality metal duct and fittings to reduce friction and, as you say, reduce the possibility of ignition.

 

[Mark Hepburn]

I just installed a clearvue cv1800. I am using the Wynn cartridge filters that they sell, but venting to the outside is better. I would look at this one:

http://www.clearvuecyclones.com/cv1800-series/25-cv1800-lh-single-phase-no-filters.html

See Stumpy Nubs' web site for a discount:

http://www.stumpynubs.com/dust.html

Discount code is nubs5

Since you can get the wiring done yourself, don't spend the $250 on the optional electrical box, it is something you can do for about $25 yourself.

6" Thin Wall Gravity Feed Sewer and Drain is cheap, easy, and works fine.

Hey Dan, Thanks for the links. I hadn't really looked at the Clearvue products before and they're pretty compelling. Comments about them are great and I like the fact that it uses a Leeson motor and has a larger impeller. Very small footprint too. I'd say it's an appealing option (but I confess that the Felder is what I'd go with if I had the ready funds).

I also like that the ClearVue can be bought with no filters. So I can just vent it. The only thing I object to is the use of MDF. No way could that go outside but on the other had, it has a very small footprint and I could frame up a little closet for it with filters as Ron suggested, with filters for the return. This may be a very cost-effective solution if my Grizz isn't up to the task. It's rated at about 800 CFM with .5 micron pleated filter but I'm sure it's overstated. Not knocking Grizzly since I have several of their tools and they've been very good for years. Just sayin...

 

[Mark Hepburn]

Your plan sounds good. The filter may be part of the problem. I switched to a pleated filter and increased pull considerably. Also someone here did a write up on putting a wok (yes cooking ) in the machine to create a vortex like Jet does. I will give you details if you need, This also helped pull dust into lower bag and decrease the fines in my vacum room. Oh, I have mine in the attic in a sealed room with a filter on the return air.
I too wish I had the 6 inch return, just do not do enough flat work to justify the cost and climbing.
Having fun back in LA in NO for the Sugar tomorrow.

Thanks Gerald. Yes, no shop work today. Bowl games for sure. I'm disappointed that LSU didn't have a better season but Ole Miss sure looks good. Superdome isn't a place of joy this year, what with the Saints "rebuilding" and the Tigers losing 3 in a row. But we'll be having a small bowl party and even a bad time is pretty good down here

I wish I could put my DC in the attic, but alas, I'd have to open up the ceiling. If you can send the wok info I'd really like to see that. I didn't realize that Jet did anything like that. Bill Pentz did mention that Jet was among only 3 D.C. makers that properly sized their impellers.

Have a great day yourself.

 

[Mark Hepburn]

I grew up in Houston and have been to south Louisiana so I know that "static electricity" is a foreign word because the air almost always fully saturated sometimes even more than 100% (yes, it is possible to have supersaturated air). However, just to avoid the remote possibility a a tiny electrostatic shock there is conductive PVC flex hose for the short runs from the DC system metal duct drop to machine exhaust port. If you want better dust collection at the machines, more horsepower isn't going to help a lot until you improve the machine dust collection. Most shop machines do a dismal job of this. SawStop is an exception ... tyey do an outstanding job of collecting dust. Almost all bandsaws have a DC port that is hardly more than decoration. It doesn't take much ingenuity to make a lot of improvement in the way that they work. I have a Delta stationary planer and Delta stationary jointer... they are OK when it comes to dust collection, but the bottom line is that there will still be plenty of dust that you can't capture with a DC system.

I have some of the 2.5" conductive plastic hose on my shop vac. It's great to not get those defibrillating shocks.

Bill, I know what you mean about humidity. I'm not saying it's humid but I'm wearing a rebreather as I type this .

Seriously, the humidity has been so bad that it feels like a cold sauna if such a thing is possible. 70 degrees and the air sticks to you. But, like everyone is pointing out as you are, I'm still going to take it seriously now. I like the idea of conductive flex pipe for the last foot connection to the machines. I'm going to go 6" off the main down to the machine and so I expect to only use enough flex hose to connect the machinery, all of which has 4" ports. I built a huge hood around my miter saw. It's a Bosch axial 10" and it's a keeper. My shop is only 9' wide and this thing knocked a foot off the depth of my previous saw. Dust collection is about par for these things, meaning it's lousy, so lots of air around that thing for sure.

Anyway, if you could point me to where you find the conductive PVC? I'm finding lots of sheet goods online and will continue to look but...

 

[Raul McCai]

Marc,
I have two thoughts.


BTW, wood dust probably won't give you cancer. It would be more likely to cause chronic bronchitis and emphysema, neither of which is a good thing to have.

Silicosis. In my industry there is a saying: "Silica - - - The NEW Asbestos~!!" It's going to make plaintiff's attorneys very very rich

http://www.lung.org/lung-health-and...e-lookup/silicosis/learn-about-silicosis.html

 

[Mark Hepburn]

Silicosis. In my industry there is a saying: "Silica - - - The NEW Asbestos~!!" It's going to make plaintiff's attorneys very very rich

http://www.lung.org/lung-health-and...e-lookup/silicosis/learn-about-silicosis.html

Yeah you're right, but probably not the plaintiffs. I read that link article and the stuff sounds nasty. Which actually just reinforces my decision to exhaust, rather than filter.

 

[Bill Boehme]

Bill, I know what you mean about humidity. I'm not saying it's humid but I'm wearing a rebreather as I type this .

Seriously, the humidity has been so bad that it feels like a cold sauna if such a thing is possible. 70 degrees and the air sticks to you. But, like everyone is pointing out as you are, I'm still going to take it seriously now. I like the idea of conductive flex pipe for the last foot connection to the machines. I'm going to go 6" off the main down to the machine and so I expect to only use enough flex hose to connect the machinery, all of which has 4" ports. I built a huge hood around my miter saw. It's a Bosch axial 10" and it's a keeper. My shop is only 9' wide and this thing knocked a foot off the depth of my previous saw. Dust collection is about par for these things, meaning it's lousy, so lots of air around that thing for sure.

Anyway, if you could point me to where you find the conductive PVC? I'm finding lots of sheet goods online and will continue to look but...

If you want 4" hose then click here for the hose that Rockler Hardware has. They also have 2.5" diameter hose for use with shop vacs. Up here in north Texas I don't get to enjoy the Gulf Coast air that I grew up feeling, tasting, and swimming in although I don't miss it in the summer. The bad thing here in the winter is that the relative humidity gets low and then I get knocked on my can by the static discharge from my shop vac hose. I always wondered why somebody didn't make conductive plastic hose since conductive plastic has been used for decades in the semiconductor business to package static sensitive integrated circuits. So far the conductive plastic hose has been great. It has some other advantages such as being much more flexible than the typical shop vac hose, heavier duty, and doesn't build up dust on the exterior of the hose.

On your main metal ducts, bigger isn't necessarily better ... it's a balance between pressure loss due to aerodynamic drag in smaller diameter ducts and sufficient flow velocity in larger ducts. You want the flow velocity to be high enough that all of the material is carried all the way to the cyclone. If the duct diameter is too large then heavier stuff will drop out of the air stream and collect in the ducts usually at elbows. I think that for a shop like yours, six inch diameter would be fine, but I wouldn't go any larger than 8" for the main run. Keep in mind that increasing the horsepower of the motor doesn't increase the speed of air movement appreciably, because all the motors run at the same speed. A larger motor just means that the system can work with a larger impeller that has a slightly larger diameter. How many machines do you plan to run at once?

BTW, wood dust or any dust will cause lung cancer. Too bad that some woodturners are still in denial. The finer the dust, the worse it is because it is able to get past all of the natural defense mechanisms in the body ... once it gets into the lungs, it is there for the remainder of your life. Most of the respiratory protection that woodturners use ignores this. A five micron mask is letting all of the really fine stuff pass right on through. A mask rated N95 is good, but a rating of N100 or P100 is far better.

 

[olaf Vogel]

Hi Everyone.

So I realized as I was cleaning the pounds of fine dust that a) my dust collector isn't cutting it and, b) I quit smoking for a reason and don't want to swap one carcinogen for another

Anyway, that led to my researching until my eyes glazed over and my head hurt. Bill Pentz would wash his hands in exasperation because, although I've read and read, the practical application isn't sinking in. What has, however, is this: I'm ditching what I have and redoing. Currently I have a Grizzly cyclone with 4" PVC piping and flex hose machine couplings; a couple of Shop Fox fine particle filters and a larger Shop Fox hanging air cleaner. That I'm keeping. The smaller ones I moved to where I paint.


Thanks!

View attachment 9124

Hi mark

I'm in the same boat. I power sand a lot which generates clouds of dust. A few weekends ago it was inches of dust. And my 3 hp, 4" craftex didn't cut it at all.

With some luck I found a General No4 blower that's massive, with 7.5 hp.
This weekend I'll be running 10" duct work to the attic where the blower and cyclone will sit.

My reading, and multiple rereading of Bill Pentz's site convinced me go for max air flow, not suction power.
I'll be building my own cyclone (for the second time, the other still working and not worth moving)
Honestly, building a cyclone is not hard, or expensive. Bill provides good guidelines. But it seems like most of the calculations are aimed at keeping dimensions so it fits in an 8' ceiling which isn't always optimal.

The big challenged is recycling the air since the CFM rating will suck my shops air out in about 2 min and would making winter heating impossible.
In the summer I'll vent outside like you suggested.

A friend also just offered sheets of pvc they used to line walls at a pharmasutical firm, so those will become the dust shroud.

Olaf

 

[Ron Rutter]

I can't understand why manufacturers make the discharge outlets so small - e.g 4" on a table saw. It is the volume that picks up the fines not the speed ( which can cause tunneling).
Mark, an 800 CFM unit is not really adequate for most situations.
The Pentz designs require lots of headroom which probably means a side discharge drop box.

Another thing people neglect to do is WASH the DC bags. They get blinded over restricting flow.

Cheers & Happy New Year to all! Ron.

 

[Josh Stevens]

Marc,
BTW, wood dust probably won't give you cancer. It would be more likely to cause chronic bronchitis and emphysema, neither of which is a good thing to have.

Actually the International Agency for Research on Cancer (IARC) which is part of the World Health Organisation, classify wood dust as a Group 1 carcinogen which means it will cause cancer in humans. I'm pretty sure NIOSH have given it the same classification.

 

[Raul McCai]

Raul,


and, as you say, reduce the possibility of ignition.

Oh, I didn't say that. I've gone bleary eyed reading very well documented work that goes both ways on the topic and I am most certainly not an expert, but my area of expertise informs me about Insurance Company's universal and unwavering posture on the question of ducting.

If they find out that an insured has non metallic DC ducts, they will rendition him to the Chechens or cancel his policy, whichever is cheaper.


I haven't determined whether you need things like explosion vents too like the NFPA requires for industry, but If you get a written letter from your carrier ( or agent) that you don't need one, it's solid gold. Anyway always make a habit of re reading your policy declaration page for exclusions and bear in mind that the insurance company is not your friend they are the other side of a potentially costly argument.

 

[Raul McCai]

or maybe there are impellers for sale

http://continentalfan.com/e-catalog/industrial/tek-airfoil-impellers-backward-curved/

 

[robo hippy]

It is probably time for some one to do another comprehensive book and video about dust collectors. Mark, for your size of shop, if you get one of the 'good' systems, which to means Oneida, and probably Clear View (which wasn't around when I set up my DC), a 2 hp unit should work fine. I have a 24 by 36 shop, and Oneida (they will design the duct work for your shop as will Clear view) told me that 2 hp would be sufficient, but 3 hp would be better if I planned on running 2 machines at once. Having the proper diameter duct work relative to your dust collector is huge in getting good air flow. Going with bigger diameter ducts works some times, and some times not. Running too big or too little can make a huge difference when compared to 'just right'. Along with this is the pressure that is generated when the system is running. There are many ways to 'measure' and 'advertising' is not always totally accurate, so with the 'cheaper' brands, they may not come up to par with the other other systems. Best bets: get a 2 stage system so anything that goes into the hoses (bowls, spheres, rags, shavings, the shop cat) goes into the cyclone before it goes through the impeller blades. Huge savings in time saved from cleaning the blades, and in repairs from things hitting the blades. Use the pleated paper filters, and some now go down to less than 1 micron. One paper cartridge can give 2 to 3 times the surface area that 1 cloth bag does, and most of the paper filters are finer than the cloth ones. You can vent straight outside if you want. First time the wind is blowing towards a neighbor's house, there might be problems, unless they are far away. It is also a down side unless you live in a very temperate climate and can turn in short sleeves and shorts all year long. You can put the DC on a pad outside, and make a lean to for it or an enclosed shed that would classify as 'temporary' to the building inspectors.

robo hippy

 

[Mark Hepburn]

I built a cyclone based on Bill Pentz design info for our seniors WW shop.This was tied into a 3HP DC. I incorporated a drop box & made the cyclone outlet 10" instead of 8" dia. After 2 years there was only 2" of material in the DC bags. BUT, you have to remember to MT the drop box!!This also keeps larger chunks out of the impeller.
If you are not paying to heat the air discharging to atmosphere is great otherwise the air passing through the DC just returns & does contain fines - if you have no neighbors to complain!! You can put the DC in a closed room with a filter bank to clean the returning air.
In addition you could install an air cleaner. No matter what we do there are still the dangerous fines floating around.

Protect yourselves folks. I am probably going to have to quit turning because of lung problems & I have about 500 blanks of 7 or 8 different woods that I was planning on playing with....
By the way I feel the ramp in Bill's cyclone is the real secret.

Ron.

Sorry to hear that you may have to quit turning. I have thought about building one also but I keep finding that I do things that take away from my turning time, which is what I really want to do.

No neighbors at all. I've lived here since 1991 and most people don't even realize that there's a house back where I am. I'm going to exhaust and stick a vent somewhere on the opposite end of the shop for makeup air.

 

[Mark Hepburn]

If you want 4" hose then click here for the hose that Rockler Hardware has. They also have 2.5" diameter hose for use with shop vacs. Up here in north Texas I don't get to enjoy the Gulf Coast air that I grew up feeling, tasting, and swimming in although I don't miss it in the summer. The bad thing here in the winter is that the relative humidity gets low and then I get knocked on my can by the static discharge from my shop vac hose. I always wondered why somebody didn't make conductive plastic hose since conductive plastic has been used for decades in the semiconductor business to package static sensitive integrated circuits. So far the conductive plastic hose has been great. It has some other advantages such as being much more flexible than the typical shop vac hose, heavier duty, and doesn't build up dust on the exterior of the hose.

On your main metal ducts, bigger isn't necessarily better ... it's a balance between pressure loss due to aerodynamic drag in smaller diameter ducts and sufficient flow velocity in larger ducts. You want the flow velocity to be high enough that all of the material is carried all the way to the cyclone. If the duct diameter is too large then heavier stuff will drop out of the air stream and collect in the ducts usually at elbows. I think that for a shop like yours, six inch diameter would be fine, but I wouldn't go any larger than 8" for the main run. Keep in mind that increasing the horsepower of the motor doesn't increase the speed of air movement appreciably, because all the motors run at the same speed. A larger motor just means that the system can work with a larger impeller that has a slightly larger diameter. How many machines do you plan to run at once?

BTW, wood dust or any dust will cause lung cancer. Too bad that some woodturners are still in denial. The finer the dust, the worse it is because it is able to get past all of the natural defense mechanisms in the body ... once it gets into the lungs, it is there for the remainder of your life. Most of the respiratory protection that woodturners use ignores this. A five micron mask is letting all of the really fine stuff pass right on through. A mask rated N95 is good, but a rating of N100 or P100 is far better.

Bill, thanks for the link. Adding it to my shopping list.

I'm going to do the 6" duct. I read on Bill Pentz' site that you really need 1000 cfm on the vertical runs to pull the fines and exhaust. I do want a 5 hp motor just because it will have a long service life. I only run one machine at a time. I'm dead set on auto blast gates, which means that's basically my entire year's toy budget but I think it's a good way to prioritize (the whole D.C. upgrade, I mean). The only thing I'm going to sort of cheap out on are the strap hangers. 6 bucks and up, are you kidding me? I'll get some strapping at Lowe's in a roll and make my own.

 

[Mark Hepburn]

It is probably time for some one to do another comprehensive book and video about dust collectors. Mark, for your size of shop, if you get one of the 'good' systems, which to means Oneida, and probably Clear View (which wasn't around when I set up my DC), a 2 hp unit should work fine. I have a 24 by 36 shop, and Oneida (they will design the duct work for your shop as will Clear view) told me that 2 hp would be sufficient, but 3 hp would be better if I planned on running 2 machines at once. Having the proper diameter duct work relative to your dust collector is huge in getting good air flow. Going with bigger diameter ducts works some times, and some times not. Running too big or too little can make a huge difference when compared to 'just right'. Along with this is the pressure that is generated when the system is running. There are many ways to 'measure' and 'advertising' is not always totally accurate, so with the 'cheaper' brands, they may not come up to par with the other other systems. Best bets: get a 2 stage system so anything that goes into the hoses (bowls, spheres, rags, shavings, the shop cat) goes into the cyclone before it goes through the impeller blades. Huge savings in time saved from cleaning the blades, and in repairs from things hitting the blades. Use the pleated paper filters, and some now go down to less than 1 micron. One paper cartridge can give 2 to 3 times the surface area that 1 cloth bag does, and most of the paper filters are finer than the cloth ones. You can vent straight outside if you want. First time the wind is blowing towards a neighbor's house, there might be problems, unless they are far away. It is also a down side unless you live in a very temperate climate and can turn in short sleeves and shorts all year long. You can put the DC on a pad outside, and make a lean to for it or an enclosed shed that would classify as 'temporary' to the building inspectors.

robo hippy

Hey Robo;

I think I'll give the ClearVue people a call. I'm leaning in that direction because of the footprint. It'll be a two stage so as to pull the chunks out before the impeller and the rest will vent outside. I'm 200 yards from anyone on any side of the house. The shop is a converted porch that I closed in and there's a patio roof extension that provides water protection but I don't think I'd want to put the unit out there. The ClearVue would fit in a corner, I could frame it in and knock down some of the noise. Since it's inside, and essentially non-structural, no inspections or permits. Plus down here things are a bit more casual anyway

I'm using all kinds of >1 micron filters and have a pleated filter on my current D.C. and just spent the past two days sweeping up tons of dust. Thus, my decision to send it to the atmosphere, far far away from my shop

I realize that 2 hp may be enough, but since they all turn at the same speed, I don't mind going heavy on the motor for longevity and reliability. But your point is well-taken, and I'll ask ClearVue and possibly Oneida about sizing. And ducting design. I assume they need some scale drawings with reasonably accurate equipment placement?

Which made me realize that I left my jointer and planer out of my shop drawing. Of course, they're on dollies and I use them outside for now but it'd be nice to be able to just grab a spare port and stay indoors.

 

[Mark Hepburn]

Hi mark

I'm in the same boat. I power sand a lot which generates clouds of dust. A few weekends ago it was inches of dust. And my 3 hp, 4" craftex didn't cut it at all.

With some luck I found a General No4 blower that's massive, with 7.5 hp.
This weekend I'll be running 10" duct work to the attic where the blower and cyclone will sit.

My reading, and multiple rereading of Bill Pentz's site convinced me go for max air flow, not suction power.
I'll be building my own cyclone (for the second time, the other still working and not worth moving)
Honestly, building a cyclone is not hard, or expensive. Bill provides good guidelines. But it seems like most of the calculations are aimed at keeping dimensions so it fits in an 8' ceiling which isn't always optimal.

The big challenged is recycling the air since the CFM rating will suck my shops air out in about 2 min and would making winter heating impossible.
In the summer I'll vent outside like you suggested.

A friend also just offered sheets of pvc they used to line walls at a pharmasutical firm, so those will become the dust shroud.

Olaf

Olaf, I have that same thought regarding air flow based on reading Bill Pentz's site. Which I'm still reading

I'd actually like to keep it inside of 8' if I can. I have a bit of extra overhead but only a little so that would be good. The ClearVue looks as though all I have to do is put a shorter collector bin at the bottom and I'm good to go.

you for sure have more heating concerns than we do down here! Spent Christmas in a T-shirt and shorts. Hated it. I lived in Wisconsin and Ohio and miss the winters to tell the truth. I love Toronto, but haven't been there in quite a while. I was in Nova Scotia for a class in November and hoping for some cold weather. Got in the 40's but not much cooler. C'est la vie.

 

[Paul M. Kaplowitz]

Onieda

Mark, Instead of all the jury rigs and messing around, do yourself a favor and call Onieda Air. Robo and I have been around the block for many years and have a good idea what works. I have a 5 hp cyclone system that works great. Incidently, I don't care what system you use, if you are not wearing a dust mask of somekind, you will still be breathing in a bunch of sawdust. No system gets it all. I have worn an Airmate 3 for 20 years. Paul Kaplowitz

 

[Mark Hepburn]

Mark, Instead of all the jury rigs and messing around, do yourself a favor and call Onieda Air. Robo and I have been around the block for many years and have a good idea what works. I have a 5 hp cyclone system that works great. Incidently, I don't care what system you use, if you are not wearing a dust mask of somekind, you will still be breathing in a bunch of sawdust. No system gets it all. I have worn an Airmate 3 for 20 years. Paul Kaplowitz

Hi Paul.

I agree. My father died of lung cancer, and I smoked for 20 years (and quit 27 years ago). So my past lung abuse is always at the back of my mind. Sweeping out a 20 gallon bin of dust over the past week was a real wake up call.

What I have had for years is basically a bunch of ad hoc, jury rigged stuff and I just yanked it out of the shop. I do have a Trend Airshield that I use. I plan on calling both Oneida and ClearVue on Monday.

Meanwhile I have a huge fan (4' diameter) that I stuck in the door of the shop and I'm just going to let it run like crazy all the time until I upgrade. This week or next I expect to be back in business. Thanks!

 

[Bill Boehme]

Mark, Instead of all the jury rigs and messing around, do yourself a favor and call Onieda Air. Robo and I have been around the block for many years and have a good idea what works. I have a 5 hp cyclone system that works great. Incidently, I don't care what system you use, if you are not wearing a dust mask of somekind, you will still be breathing in a bunch of sawdust. No system gets it all. I have worn an Airmate 3 for 20 years. Paul Kaplowitz

I absolutely agree!

 

[Raul McCai]

I'm dead set on auto blast gates,

What's the advantage over a gate that you slide open when you approach the work station or as the need arises?

 

[Mark Hepburn]

What's the advantage over a gate that you slide open when you approach the work station or as the need arises?

My memory.

 

[Gerald Lawrence]

You know I just had a thought . If you exhaust outdoors there is less resistance because of taking the filter out of the equation and therefore 1.5 hp should work just fine. To try this out just disconnect the pipe going to the filter and try it , you should see a significant rise in suction.

 

[Bill Boehme]

You know I just had a thought . If you exhaust outdoors there is less resistance because of taking the filter out of the equation and therefore 1.5 hp should work just fine. To try this out just disconnect the pipe going to the filter and try it , you should see a significant rise in suction.

When you remove the filter and the resistance decreases the amount of air being moved by the motor increases. The volume of air being moved in a given period of time is what determines the amount of work that the motor is doing. In other words, it takes more power to move more air.

 

[Mark Hepburn]

You know I just had a thought . If you exhaust outdoors there is less resistance because of taking the filter out of the equation and therefore 1.5 hp should work just fine. To try this out just disconnect the pipe going to the filter and try it , you should see a significant rise in suction.

Gerald, I struck a compromise with my dearly beloved. I can put the dust collector outside (and I will enclose it), but she insists that I use the filter so there's not a bunch of discharge visible in the yard and such. Ergo, a filtered system but outside and therefore I can't benefit from my existing machine (which is rated at 750+ CFM but the ratings are suspect).

I'm therefore going with an Oneida V-series, most likely a 3.5 HP unit, rated at about 1450 CFM (2200 + "free fan"). My max run is going to be 22' on one side with the lathes at the end of that and nothing else. Branching off of that to the other side of the shop will be the rest of the connections and a blast gate will control that branch.

I considered the Penn State for the footprint and after reading a LOT, came away with the belief that they're a bit like Grizzly - you may get a great machine or you may have some issues. I've been very pleased overall with my Grizzly tools (T/S, band saw, jointer, shaper) but the D.C. has been a letdown for me so I'm going with a machine that is generally very highly regarded (still wish I could get the Felder but $$$$).

 

[Bill Boehme]

Your wife is a very wise person. Even though you said that you don't have any close neighbors, there is a very close neighbor whose home adjoins your shop. I know that many woodturners say that they vent their DC outside without a filter, but when you do that, your DC has to draw an equal amount of replacement air from somewhere ... that "somewhere" being the great outdoors that you've just polluted with billowing clouds of fine dust. Unless your location always has a wind blowing from the same direction that enables you to put the exhaust downwind, you may wind up drawing in dusty replacement air that you've just exhausted. Being somewhat familiar with Gulf coast weather, I know that much of the time there is no breeze whatsoever and if you create a cloud of dust around your shop, that is the "fresh" air that will be coming into the shop.

 

[Mark Hepburn]

Your wife is a very wise person. Even though you said that you don't have any close neighbors, there is a very close neighbor whose home adjoins your shop. I know that many woodturners say that they vent their DC outside without a filter, but when you do that, your DC has to draw an equal amount of replacement air from somewhere ... that "somewhere" being the great outdoors that you've just polluted with billowing clouds of fine dust. Unless your location always has a wind blowing from the same direction that enables you to put the exhaust downwind, you may wind up drawing in dusty replacement air that you've just exhausted. Being somewhat familiar with Gulf coast weather, I know that much of the time there is no breeze whatsoever and if you create a cloud of dust around your shop, that is the "fresh" air that will be coming into the shop.

Bill, you are right indeed. She is a very wise person and generally sees the "big picture" where I may get lost in the weeds of details. In truth, I didn't consider that we are our own neighbors.

 

[Mark Hepburn]

Pulled the trigger

Thanks to everyone for your advice. Lots of very good help and I really appreciate it.

So, I just ordered the 3 HP V-series from Oneida. 1,349 CFM at 2.3" SP with filter attached and fan under load. That's twice the rated CFM of my Grizzly and I suspect that it was a generous rating. Oneida's going to do the duct design free with the purchase and so that's next up.

I asked about the return air and their rep said that I could actually put the HEPA filter in the shop and let the DC exhaust into the shop. My reply was, well, you're pretty confident in the filtering capability of our system and Chris said, "absolutely".

However, he also agreed that an alternate makeup air vent elsewhere in the shop was fine if I didn't care about conditioned space, and so that's the way I'm going. So the entire system will be outside. The V-series isn't really rated for outdoors unless it's enclosed, but they say that a simple exterior grade plywood housing is just fine.

He also told me that the Super Dust Gorilla is rated for outdoors but that none of the filters are, and so it doesn't make sense to pay a premium for the unit (and double the shipping), so the V-series made the most sense.

I've decided that, although there's no danger in using the PVC, I'd rather have a turnkey system so to speak, and after I submit my shop drawing to scale, they'll return a design with bill of materials and I'm good to go.

Still plan on going with those blast gates but, Raul, I found the Long Ranger switching system may be a better option as you suggest. It'll cost about $200 compared with $1300 if I go with the auto gates. I'm thinking that it's an upgrade for down the road maybe, since that's an awful lot of money. In fact, I had wanted to get a Powermatic drill press to replace my aging Ridgid floor unit and that costs about what the blast gates do.

So there's my tool budget for a long while, and if you see me posting things for sale you know why - subsidizing my DC. But I think that it's definitely money well spent.

Thanks again to everyone for your thoughts!

Mark

 

[Larry Morgan]

If your planning on direct venting to the exterior outdoors, you need to take into consideration a few items.
- Any air your exhaust out of your shop will be replaced with air coming inside your shop from the outside.
- Therefore consider where is the nearest openings to your home or shop in relationship to your dust collector exhaust. You do not want to suck contaminated air back into your home or shop that you just exhausted.
- How much additional money will it cost you to operate your system? Heating, Cooling and De-humidification of the replacement outside air to your shop.
- If your home is too tight and your system is too large, you may have difficulty opening doors that swing out from your shop area to the outside as negative suction pressure will become a factor to consider.

I will add more as I think over this topic a bit.

 

[Mark Hepburn]

If your planning on direct venting to the exterior outdoors, you need to take into consideration a few items.
- Any air your exhaust out of your shop will be replaced with air coming inside your shop from the outside.
- Therefore consider where is the nearest openings to your home or shop in relationship to your dust collector exhaust. You do not want to suck contaminated air back into your home or shop that you just exhausted.
- How much additional money will it cost you to operate your system? Heating, Cooling and De-humidification of the replacement outside air to your shop.
- If your home is too tight and your system is too large, you may have difficulty opening doors that swing out from your shop area to the outside as negative suction pressure will become a factor to consider.

I will add more as I think over this topic a bit.

Hi Larry. I'm going to put the DC outside in an enclosure but have a return air so it doesn't pull from the house. I did purchase the Oneida with the HEPA filter but it won't be returning to the shop. I'm going to pull from the other end of the shop about 22 feet away and around a corner.

I'm in South Louisiana where we're currently suffering through a 52 degree winter day Because the shop is a converted porch and therefore a part of the house, there are two doors, both of which I will be upgrading the seals on this weekend. However, just a tad of negative pressure is A-OK with me, as it will keep dust out of the house.

I spend about 6 hours a week in the shop now but hope to spend more. So doubling that will mean that I have increased demand on the house's HVAC service for about 7% of the time in any given month (about 720 hours/month into the 48 per month of shop use). If my cooling cost doubles - and I don't think it will - during those times, then I'm looking at about a 7% increase in the A/C portion of my energy bill. The house is all-electric and cooling days far outnumber heating days down here. And actually, in this shop, I work with the door open about half the year or more, since I like the cold (such as it is here).

Dehumidification is a subject that, frankly I hadn't considered. There may be some benefit to putting this in the shop, if only to help slow some components from rusting over time.
I'd for sure like to hear your thoughts so fire away!

Mark

 

[Mark Hepburn]

Marc,
I have two thoughts.

First, before you buy anything new, why don't you hook the exhaust on the collector you have now to the outside and see what happens? The decreased resistance might make enough difference to solve your problem at no cost.

Second, PVC pipe as ducting has a lot of static electricity and a smallish internal diameter. You could try replacing the PVC with metal ducting to reduce the resistance to airflow some, and improve your through put. It might make enough difference to solve the problem, at modest cost.

BTW, wood dust probably won't give you cancer. It would be more likely to cause chronic bronchitis and emphysema, neither of which is a good thing to have.

Hey again Dean. I'm going with the metal ducting after all. Oneida is suggesting 7" with this system and reducing to 6" at the drops (then to 4" hose if I must for the machines' dust ports).

I really wanted to upgrade my DC so didn't try what you suggested. However, I did "verify" that the Grizzly DC CFM was based on free fan speeds and not with filter attached, so the usable CFM was quite a bit less. More important to me is that the Oneida that I ordered generates 1422 CFM with filter and so it's a huge increase. I'm going to see if I can sell the Grizzly locally on Craigslist, with all the hose, PVC, and fittings. Hopefully someone will want it.

 

[Larry Morgan]

Hi Larry. I'm going to put the DC outside in an enclosure but have a return air so it doesn't pull from the house. I did purchase the Oneida with the HEPA filter but it won't be returning to the shop. I'm going to pull from the other end of the shop about 22 feet away and around a corner.

I'm in South Louisiana where we're currently suffering through a 52 degree winter day Because the shop is a converted porch and therefore a part of the house, there are two doors, both of which I will be upgrading the seals on this weekend. However, just a tad of negative pressure is A-OK with me, as it will keep dust out of the house.

I spend about 6 hours a week in the shop now but hope to spend more. So doubling that will mean that I have increased demand on the house's HVAC service for about 7% of the time in any given month (about 720 hours/month into the 48 per month of shop use). If my cooling cost doubles - and I don't think it will - during those times, then I'm looking at about a 7% increase in the A/C portion of my energy bill. The house is all-electric and cooling days far outnumber heating days down here. And actually, in this shop, I work with the door open about half the year or more, since I like the cold (such as it is here).

Dehumidification is a subject that, frankly I hadn't considered. There may be some benefit to putting this in the shop, if only to help slow some components from rusting over time.
I'd for sure like to hear your thoughts so fire away!

Mark

Mark:

I am a registered Professional Mechanical Engineer that specializes in HVAC, Air Flow, Fluid Dynamics and Thermodynamics. I have several questions before I can provide a reasonable answer to your electrical bill increase.

1. Is your current AC system for the house also supplying air to your shop?
2. Does any air from your shop return to the AC system in question #1 above?

If so, then the following will apply: I can assure you that your electrical bill will increase more than 7%. One needs to consider that a normal AC system will take room air at approx. 75 degrees and cool it to 55 degrees (total temperature change of 20 degrees) thus lowering your Relative Humidity (RH) to approx. 50-55%. Any outside air (assume 90 Degrees) will need to be lowered to 55 degrees (total temperature change of 35 degrees) to obtain your desired RH. To determine a correct estimate of electrical bill increase would require a mass flow calculation that requires CFM of DC and home AC unit as well as time intervals.

If you have a complete separate AC system for your shop this all changes but will still have a similar impact.

My DC system recirculates in the house. My DC is separate from the work room located in a large mechanical room just on the other side of the shop wall. I have a small encloser around the DC with fiberglass insulation in the joist spaces above the top of the wall. I also have a series of 2" Pleated HEPA filters in a bank on the walls of the surround. Make sure to caulk and seal all cracks and other openings. The more square inches of filter space means that you will have a lower velocity across the filters thus trapping more dust particles. Now, believe it or not, the dirtier the filter, the more efficient it becomes. But you also increase a static pressure.

This may be more than you want to know.