Cyclone.. By-passing filters to Outside?
I have a question for anyone that may have by-passed their filters al-together and exhaust the fine dust outside. I have considered making a somewhat short pipe run from the outlet port that normally goes to the cannister filters directly to and through an outer wall about 6 feet away.
My question is.. I have doubts without prior knowledge that there is enough force to move the fine dust that far without it caking in the pipe. I could use clear plastic pipe so I could monitor if that occurred, but… if there is not enough force to move it I would prefer to abandon the idea before cutting a hole in my outer shop wall and installed a down hood to keep rain out.
I am in the Atlanta area and having a relatively long period of fair weather (usually from late March to late Nov) that the temperatures are not cold enough to warrant turning on the heater, this would be ideal and eliminate any problems that are created with clogging filters. After having read the Bill Pentz site thoroughly several times, I am suspect as to what all manufacturers claim their filters will do. Actually I am suspect of what they don’t tell you they won’t do either intentionally or not having done enough digging to really understand what effects what!
So… bottom line: What is the longest run by-passing filters with the Cyclone sitting inside has someone made without problems. And if they did en-counter problems, what were they?
BTW.. I could just move the Cylclone to an outer wall… but where I have it centrally located makes for no more than an 8′ run to any machine with 6″ pipe or flex and I have converted all machines to accept a direct 6″ dust port so down-sizing was intentionally eliminated.
Thanks in advance if you can help as I have to get to work and won’t be back till latter to-night…
Regards…
Sarge.. jt
Replies
Sarge,
You won't have any more of a problem with dust build up on the outfeed pipe than you would on an infeed pipe, in other words it shouldn't be a problem.
There are three potential problems however:
1. During some times of the year you will be exhausting air that you just invested some money in either heating or cooling, so exhausting to the outdoors will add to your utility bills.
2. If you have a gas or oil fired furnace or water heater in the shop, or elsewhere in the same building, the cyclone will pull make up air down through their chimneys creating a very real risk of carbon monoxide poisoning and a possible fire hazard.
3. Moving the dust outdoors exposes other people nearby to it and to the noise of the exhaust. If you have a neighbor close to the shop, they might not be pleased with the new set up.
John White, Shop Manager, Fine Woodworking Magazine
>> You won't have any more of a problem with dust build up on the outfeed pipe than you would on an infeed pipe, in other words it shouldn't be a problem.Let me just add that you will infact have slightly more CFM when you remove the filter. Even the most effecient filter restricts the CFM and CFM is what keeps the dust and chips in suspension.Whether you exhaust outside may depend on where your neaghbors are and local EPA codes in you area. Where I used to live, outside exhaust was banned.Howie.........
John....
Thanks for the speedy reply as I don't have to leave for work for another 30 minutes.
(1) Not a concern with utility bills as lungs are more of a priority. And here in Atlanta, I only have to run the gas heater in the shop at night basically from mid Nov. to early March.. when in the shop as it will bring it up to 70 degrees within 10 minutes. I thought I would connect the filters at that point for total inside use.
I don't need A/C in my shop as it is in a 2 car drive under the house garage surrounded by large trees for shade. With poured concrete walls the shop and 10/2 basement stays cool enough except in mid summer when a 20" fan will do a sufficient job with the doors open.
(3) Not a concern as I intended to put the Cyclone inside and just run the exhaust pipe out the outer wall. Again I am surrounded by larger trees and not a house within about 80 yards. Live in a cul-de-sac that backs to another cul-de-sac and very large lots for each house. It keeps us pretty well separated.
# 2 on your list is my main concern. I do use a gas operated central heating system in a walled off 1/2 basement behind the garage-shop. I was aware of the problem that could be encountered with carbon monoxide. But... the garage doors do not seal air tight and I won't seal them in my climate. And if necessary, I could raise a door slightly to allow even more fresh air in even in late winter and fall. Again.. I will go to the filters in late November through early to mid March in what is about the really only moderately cold weather we have in Atlanta.
Your thoughts here would be appreciated..... off to work!
Regards...
Sarge.. jt
Edited 4/12/2007 12:22 pm ET by SARGEgrinder47
To be safe with the exhaust issue you have to be sure that in no way are you pulling air from the main building. Even if you have not or are not using anything with gas you can still cause issues related to sick building syndrome (not really sick building syndrome but related issue).
My concern is that you really are not outside the building envelope. Your shop is in the basement so you will draw air from the adjacent walls and down from the floor above remember the walls and floor are not air tight.
Now you have to remember that you are moving HUGE amounts of air. Figure out what the CFM of DC is and divide that first into you shop and then into your house and will be amazed and how soon you will do a complete change of air. Also keep in mind that in order to let air into the space you need a LOT bigger hole the the one going out as the one going out is forced and the inbound air is not. I would have to consult an expert but I would not be surprised if you need something like a couple foot hole to allow the air back in.
If you don't have it will you get sick or die? Most likely not (if you are not using gas fire things or fire places or other stuff that burns and emits bad air) but you may get sick and in theory you could die. I would say this offsets the idea of protecting your lungs.
Also don't forget that you are moving air from inside to outside not from inside to inside. So if you think that a filter will slow your airflow down I have to think this will be worse after a while. Eventually if you have a small enough space you are pulling from you will start to loose ground on this. As the air in the space will resist forming a semi vacuum. So you will not get as much airflow as you may think. The solution to this is to open a window and then you have free airflow. But I am not sure you are saving much and you are definitely causing other possible issues.
We has a thread about this last fall sometime. You may want to look into that thread also.
If I was me I would not do it but to each their own. But if you do do this PLEASE make sure you do not run this when the gas water heater or such is on. We would miss your posts around here.
Doug Meyer
I believe Doug touch on this topic with me awhile back. I would definately take a minute and listen to what he is saying. You can and WILL run into dangerous problems with exhausting all the dust outside. I know, I tried it and almost killed myself. I know up front it sounds like a great idea and picking up all that CFM is great, but remember, what you push out has to be replaced. I have a Shop Fox 1800 CFM dust collector hooked to 5" piping that run to all my machines (7) and I cut a hole in my building to exhaust everything outside. Trust me, it works great, BUT:
1. I have a 30'x30' dedicated workshop that is heated by a garage ventless propane heater. When I turn on my dust collector, it takes about 40 seconds and my shop goes from 75 degrees to 55 degrees when its cold out.
2. I also have a small woodburning stove that I use to supplement the small garage heater when I am working. Basically, I burn all my scrapes. This stove has 6" pipe run through the roof and I can burn a very hot fire, close the damper, open the front door of the stove, turn on the dust collector and there will be ZERO smoke coming out of the chimney!! I can actually draw all that smoke back down the pipe.
3. Don't make the mistake of not listening to Doug and others here. Now I have a 6" hole in my building that I have to fix and come up with a better method.
I am one of the biggest fans of woodworking, but its still not worth dying for.
Please be careful,
Jeff
Morning Doug...
Now, I like the way you emphasize HUGE amounts of air. Being a non air engineer NOT.. I was not aware that the amount indicated and mentioned by yourself, John W.. Howard.. Jeff and JM was that large. It was a concern as I did read something to that effect on the Bill Pentz site as he states that a lot of commercial environments have the whole shooting match outside which doesn't pose the problem. And one of the main reasons I ask. That and I am more familiar with happens on the incoming side of the cyclone and wasn't sure of the force on the out-bound side.
And I agree with "to each his own", but mama didn't raise a complete fool. So..... in lieu of what has been said the plan has been partially abandoned and will be modified to compliment the warnings you guys have presented and not just ignore them.
With great weather as a whole on my side, I will have a dual hook-up on the out-bound side. A short flex pipe to go the filters and a longer one to be used on a lovely day as today in Atlanta. The longer one can be used for direct exhaust by just walking it out an open 9' x 9' foot raised door and place the out-bound pipe opening facing away from the door. With two 9' x 9' doors open at once, that should allow plenty of fresh air to get back inside and not pose a problem it would seem?
Any day that is not comfortable enough (and that is only short periods in the Atlanta area) to open those doors as I usually do in the many mild months we have here, the secondary flex pipe is attached to the dust exhaust and directed to the filters. That should provide the necessary air replacement with the double doors closed to keep heat inside.
A carbon monoxide monitor has been in place for years after I installed a gas space heater by tapping into a 1/2 natural gas pipe going to my fire-place starter. That is a back-up precaution in case of gross mis-calculation of what those non-sealed doors offer in the way of ventilation with the doors closed.. heater on and cyclone running with direct hook-up to the filters.
I stop every hour or so even in warm months and blow out the shop starting in the rear out open doors with an electric leaf blower anyway. I wear a mask when doing it and go upstairs for a cup of coffee till the fine dust settles. So.... I don't really mind cleaning filters outside with compressed air with an air compressor. Mama didn't raise a complete "lazy" fool either.
If you or anyone sees any leaks in the above plan.. I am all ears. If you want to fix a leak, you have to identify where it is and then don't spare the duct-tape. If ya can't fix it with careful though and duct tape...... chances are it can't be fixed! ha.. ha...
Regards...
Sarge.. jt
HI Sarge,I used to commission and install dust collectors in a previous working life.Horizontal runs of pipe need a minimum 18m/sec to keep the dust in suspension (sorry, I haven't time to convert to fpm - conversion is 18x60/0.0254/12 = xxxx fpm)If the airflow is any less than this, then the dust settles on the bottom of the pipe until the airspeed in the remaining (unblocked) duct is 18 m/s. If you leave it alone, then the dust tends to reach a state of equilibrium in the pipe. Perfectly fine with cement or things that aren't flammable, for a flammable dust, I'd be aiming at the 18m/sec figure as the design point (maybe 19 to be safe - it's a tradeoff between air volume and power/pressure loss.)Trust that this helps,eddie
Morning Eddie...
Thanks for your in-sight as always. I usually let a vacuum system run for a minute or so after I have complete cutting to avoid loss of air-flow that will allow it to settle. I intend to use clear 6" pipe that I can actually see chip or dust build-up if it occurs. A quick burst or two with about 40 psi pressure from an air compressor hose pushed to those points should dis-lodge any build-up that I see occur.
The advantage I hope I have created by positioning my Cyclone almost center shop and backing my major dust-makers to it is I don't have a lengthy reach for them with long runs of pipe ducting or PVC that you can't see through visually to detect build-up.
Two-fold reasoning IMO. (1) Visual monitoring of build-up and increased cfm movement by keeping the run no longer than 10'-12' with clear piping (most under 6') on the in-bound side. The 6" pipe from that in-bound side will go directly to my machines which I have modified to accept 6" duct ports. No down-sizing and subsequent cfm loss from doing so.
The out-bound side will be clear 6" flex pipe which will run no more than 12' when I do open doors in my great weather and walk it's exhaust opening outside for direct exhaust. About 4' max on another 6" clear pipe when I have the doors closed and direct the out-bound directly to the filters inside that sit beside the cyclone itself.
(2) I should have plenty of cfm power with those direct hook-ups to one machine at a time with matching 6" ports and pipe size when connected to the twin tower filters. I don't mind a quick dis-connect from one machine and re-attaching to another. Not at all. The day I'm too lazy or physically in-capable of manually making the quick change is the day I will order power windows for my pick-ups and stop leaning over to roll a window down as I do.
If I were a commercial venture with dead-lines... time is not on my side. Under those circumstances I personally find it reasonable to set up an elaborate system with blast gates to each machine and just open or close them as needed to save valuable time which translates to money. But... in all reality, I'm not and don't intend to be! ha.. ha...
Regards...
Sarge.. jt
Hi Sarge,If I recall correctly, you're installing your new Penn State cyclone. I'm eager to hear about your experiences with it once you get it up and running.I did the math and 18 m/s translates into roughly 3500 fpm. On the back end of your cyclone, I'm pretty certain you're going to be pushing a lot more than that. My assumption is that your cyclone can / will push more than 800 cfm and you're working with 6" pipe. Just remember that the system has to balance -- if you can pull 800 cfm @ 4000 fpm at your tools, the cyclone has to push that out.You would be fine opening just one of your garage doors to allow outside are in when the cyclone is running. That's a *huge* hole when you think about airflow. And from other comments that you have made it sounds like you're going to end up with a safe setup.Please let us know your thoughts on your new cyclone!Glen
And I think you are probably going to be correct DD. But time will tell and that time is near. Whatever happens will get told as I don't intend to "sugar-coat" it.
I will add that I have intentionally set up for peak efficiency by keeping my set-up simple with the space I have and other other determining factors that may be unique to my shop. I doubt two of us have the same exact conditions to work with. I hope to report that "simplicity" is enjoying it's finest moment at "Sarge's one-horse saw-dust bar and grill". ha.. ha..
Time will tell and if I don't get off this computer, it ain't gonna get done!
Regards...
Sarge.. jt
Dear Sarge,
I have exactly the same setup and what John W. offers is true. I have my exhaust pointed down and it even keeps the leaves clear, never mind dust in the pipe! I am in the sticks, so only the trees will get cancer. Do heed that waring about make up air. In the winter, I crack open the window that is closest to the machine that I am working with, that way it is sucking in some cold air as well as the warm shop air. I have never had a problem with my wood stove drawing back into the shop, but it isn't something to be fooled with either.
Best,
John
Sarge, the latest FWW #191 has a Q&A on cyclones with a twist. The cyclone is outside and the filter is inside with some additional advise from the pres of Oneida. I am looking forward to your Penn State impressions on the cyclone build quality.
Life is what happens to you when you're making other plans .
Morning Jerry...
I just read that with your comment as I received my copy just yesterday while at work. BTW.. from a quick scan, the articles looked better than usual and caught my attention while finding the bit on the cyclone. Nice going there Asa!
The article was written with keeping noise at a minimum and that's why he decided to go out-side. I could do that on the back side of my my shop by adding an enclosure under my jutted out break-fast nook upstairs overhead on that end. But I would have to pour concrete under it and enclose to avoid moisture getting into the Cyclone in heavy wind when raining. The noise issue is mute for me as I lost some of my hearing in VN and can't hear what most with normal hearing can also. I also wear a pair of Smith & Wesson magnum ear protection along with a quality dust mask. I didn't used to but do at this point.
What I can tell you about the Tempest 1425 S at this point is the finish is fine. 17 gauge construction and the aluminum blower fan is 8 fin. What I can't say at this time is how it is going to work yet. I'm almost complete with mount and have the new 220 V line laid. I have sealed everything that could leak with silicone. Not a seam got over-looked that I am aware of. 6" dust ports are almost in place and fine tuning details are in progress.
But the real deal won't get revealed until late Sunday or next week if I get off schedule where about 200 linear feet is going through it with a jointer and planer. That should give me a better understanding of what I have and don't have!
Until then.....
Regards...
Sarge.. jt
Edited 4/13/2007 12:20 pm ET by SARGEgrinder47
Sarge, the point I was trying to make is that filter dust is usually not a problem unless the bin overflows. Cyclone users always report that very little dust ends up in the filter.
BTW the latest FWW is excellent as it contains a lot of relevant articles and test reports.
Life is what happens to you when you're making other plans .
Afternoon Jerry...
And that's what I had always been led to believe also. But.. if you read through the Bill Pentz site as carefully as I have several times, he insist that what the manufacturers claim their filters will do is not true. Basically he says they will clog in a very short time and pass the fine dust back out and slow the cfm down to a point that it won't get much farther than the machine in the first place.
Only the Clear-vue (which is his design basically).. Felder (which is out of most of our price ranges) and his home-built cyclone using his choice of filters.. motor and design elements are going to get the job done, ya-baa.. ya-baa.. ya-baa.
I can't get a true read on if he's overly fanatic with his existing, horrific lung conditions or what he says is correct to the letter. If so... someone out there selling cyclone systems is blowing smoke with their claims of what can be achieved and I do realize that it is a highly competitive market with the possibility of even becoming cut-throat, especially with big volume discount dealers like Grizzly getting in the act and possible elimination of smaller mom and pop distributors who operate with much higher over-head?
So.. having decided that the basic design of cyclones is simple enough that even I could understand at least the laymen points without an engineering degree, I would like to clear some of the air that obviously someone is blowing and see what's really behind the smoke-screen! If nothing else out of just pure curiosity as this whole subject has become somewhat of a challenge to break down to the "truth and nothing but the truth" and my mind needs that on occasion. ha.. ha...
Back to the shop and regards...
Sarge.. jt
I did exactly this. No filters or bags: just straight blow out to the outdoors. I live on a farm and so there are no neighbor issues. But there is the thing about pulling heat out. My saving grace is I don't have the machine on constantly. Generally just seconds to a couple minutes at a crack when sawing, planing, etc.
I think you have an appropriate set-up with short burst BC.. I can't imagine that you are sealed so tight under those circumstances that carbon monoide could built. But.. an investment in a carbon monoide warning device is very cheap really and the Ace that could be up your sleeve. Just a thought!
Regards...
Sarge.. jt
No way is this building sealed to that degree. It's a typical steel barn type.
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