Dust Collection. Single stage vs cyclone

[Bryan Solomon]

I am in the process of building a new shop. Proposed size to be 30' x 27' with a loft above that measures 10' x 25'. The internal ceiling height will be 15'. This will be close to triple the size of my previous shop, which I am very excited about. I need some help with a dust collector, being the one I have been using is extremely undersized (1 hp bag type woodtek I bought when I was 13 years old). I called Oneida a few weeks back and was told I needed a 5 HP cyclone, which is about $4,000 along with a ballpark of another $4,000 worth of duct work. If I were a betting man, I would say whoever I spoke with must work on commission.

I started looking into this more and quickly realized the difference in CFM ratings between and single stage and cyclone collector. A single stage collector has almost double the CFM rating for round about half the price of a cyclone of the same horsepower. I don't quite understand the advantage of spending the extra money for a cyclone if it moves less air? If it moves less CFM, does that also mean that is has less suction? I see grizzly sells a 3 hp single stage dust collector with 1 micron filters on top for about $800. And if I really needed the 5 hp, I could get two of these for still about half the cost of a 5 hp cyclone. And to keep the floor space clear, I could put both of the single stage collectors on platforms high up on the wall (ceiling height will be 15'). Am I thinking about this correctly???

Here is a list of the machinery I have that need dust collection:
Powermatic 66 5hp table saw
Powermatic 100 12" planer
Delta 28-206 14" bandsaw
Oliver 4240 10" jointer
Mitersaw station
Router table
Would like 2 floor sweeps

Advice on this is much appreciated.

[David Walser]

Bryan -- I believe all of us who've gone down this road before would say you want a cyclone. There are lots of woodworkers who started with a single stage dust collector, grew dissatisfied with the performance, and switched to a cyclone. In my case, I 'converted' my single stage collector into a cyclone. The only part left from the DC is the blower and the upgraded filter (my first attempt at getting the DC to work better.) I really wish I'd started with a cyclone.

Before I take a stab at telling you why you want a cyclone rather than a single stage dust collector, let me address your concerns about CFM. The CFM ratings of single stage dust collectors are significantly overstated. The CFMs are measured at the inlet without any dust bags or filters attached. So, yes, if the marketing department hasn't 'improved' the numbers by rounding up, the blower can move that much air. But, that's hardly a real world number. What's important is how much air can the unit move through your ducts WITH the filter installed. Cyclones are measured differently. The CFMs are measured at the inlet to the cyclone -- usually with the filters attached. (And, yes, a cyclone reduces air flow. It takes energy to spin the air in the cyclone. That energy consumption reduces the amount of energy that can be used to move air through the machine. There is no free lunch. So, a cyclone with the same blower as a singe stage DC will have a slightly lower CFM rating.) This isn't a real world number, either. Again, your ducts aren't attached to the inlet. Obviously, the maker doesn't know what everyone's ducts will look like, so they just measure at the inlet.

So, why a cyclone rather than a single stage unit given that even a well-designed cyclone will reduce air flow? The issue isn't which unit will move the most air when the filters are clean. The issue is which one will move the most air after 15 minutes of use. With a DC, all the fine dust will be trapped by your filter. That very quickly reduces CFM! With a well designed cyclone, very little of the fine dust reaches the filter -- it's been removed by the cyclone. That means your cyclone will be working as well as it was right after the filters were cleaned after 15 minutes, 15 hours, or 15 days of use. And, when your cyclone is operating at 99% of its peak capacity, it will be moving a lot more air than your DC would be at 50% of peak capacity.

Obviously, the discussion above assumes the DC and cyclone have the same sized blower and motor. However, as you may have noticed, it's really hard to find a single stage dust collector with a 3hp (or larger) motor. Why is that? It's because large commercial shops and industrial plants don't use single stage dust collectors. Obviously, they could make really large single stage dust collectors. And, if the single stage design had material advantages over cyclones, they would be making them and that's what commercial shops and industry would be using. They're not making large DCs and industry isn't using them because the the filters would need to be cleaned constantly. When I worked at a furniture mill while I was going to college, the mill had two giant -- three story tall -- cyclones that served the entire mill. There was a railroad car parked underneath the cyclones to catch the shavings. We filled it up once a week. Two or three times each year, when we were milling wet wood, the chips and dust would cake the inside of the cyclones and they would quit working. One of us would need to climb inside the cyclone to knock the chips and dust off the walls of the cyclone. (Dangling from a rope inside a cyclone can be fun! Just don't let anyone turn the cyclones back on while you're in there...) The process of unclogging the cyclones took no more than 15 minutes. That was the only attention they required. How often would we have needed to clean the filters of a single stage DC of a similar capacity?

As for whether or not Oneida is giving you good advice, I suggest you compare their answer to what you hear from ClearVue. A lot of this will depend on the layout of your shop and your ductwork layout. The more branches and drops you have, the more capacity the cyclone will need. For that reason, I suggest you don't use floor sweeps. I get the attraction. I loved the floor sweeps we had at the mill. However, the two sweeps are two additional sources of leaks and add to the overall length of the ducts in your system. Instead, I suggest you use flex hose quick connects at a couple of your machine drops. You can then use a length of flex hose and a 4' length of 4" PVC to act like a vacuum hose to clean up your shop. I uses something similar to this from Rockler (my version is no longer made): https://www.rockler.com/rockler-dust-right-4-quick-change-floor-sweep. With Rockler's 21' collapsable 4" flex hose, I can clean my entire shop. I use it to vacuum off my workbenches and to sweep the floor. It works great and I find it more convenient than the floor sweeps we had in the furniture mill.

[james manutes]

Great response David ! Very few guys remain w/ single stage collectors . Keeping the filter clean is the key . Bill Pentz suggests 800 CFM to capture all the finest , smallest dust , and that is not cheap to achieve . I'd say the first step is to try to settle on the basic duct layout , w/ the focus on it being leak free . Leaks will set you back , so do what you can to eliminate them . Cluster tools if possible , keeping the system smaller . I think in a shop less than 900 sq. ft. , a 3HP Clear Vue or Onieda system will be enough . You are probably at the limit of a shop built cyclone , but a well thought out one could get you close . Some tools will benefit from changing the ports on them . Four inch ports will choke the system , try to avoid that . I also like the Rockler expandable hose , no longer use a floor sweep . Bottom line , I don't think you need a 5 HP system .

[james manutes]

My mistake , the CV 1800 is a 5 HP motor . It is priced like a 3 HP Onieda , but I thought it was 3 HP .

[Jim Becker]

Bryan...CFM ratings. Not something to rely upon on mass market machines and their advertising. They will never come even close to that level of performance in the real world. They are generally bogus and those "big" numbers can only happen if the unit is running unrestricted by ductwork right to the point of motor failure. If you cannot get a fan curve for the unit you are considering, then you will not know what the capability of the collector will be when hooked up to a ductwork network. The specialty dust collector companies generally provide fan curves which clearly indicate what the expected CFM will be over the possible conditions it will be employed.

The advantage to a cyclone is the pre-separation which allows for easier handling of collected debris and helps to improve filtration.

I'm a very happy Oneida customer. They know what they are talking about. (there are more economical sources for the duct work, however) I feel the same about Clearview. Grizzly's long cone cyclones also seem to be good products...you may or may not be able to get fan curves from them...I don't know.

[John K Jordan]

Brian,

It's been a while since I researched this for my new shop (2012 or '13), but at the time I decided on the 5hp ClearVue cyclone for some of the reasons David W mentioned in his excellent post. I've been quite happy with the performance. I see the cost now is under $1800. You do have to assemble it but that was trivial - much easier than installing all the duct work!
I used 6" PVC pipe for the main ducts and drops. I put my main ducts above the ceiling in the trusses.

One thing about a cyclone - the longer the cone the better the separation. The cone on the ClearVue is fairly long. Mine passes almost nothing to the filters - even powder-fine dust is dropped into the can.

My ceilings are 9' and the cyclone barely fit with a 30gal metal trash can as a bin. When sizing a bin, consider the weight of a bin full of fine sawdust and the path from the cyclone to the outside. I wouldn't want to handle a bin much heavier than the 30gal can, at least not by myself. I use a hand truck to move the bin outside where I lift it to the back of a truck to take it where I dump it in the woods. Most of the sawdust I collect is from the bandsaw, lathe, and sanders. Planer/jointer shavings will fill up the bin a lot quicker but with much less weight.

You DON'T want to overflow the bin under a cyclone - that can send sawdust to the filters and cause a mess to clean up. I haven't done this but I've read reports of others who have. One advantage to the ClearVue is you can see inside as it's operating and even see if the bin is full (but I occasionally pull off the lid to check if it's almost full).

A big cyclone can be deafeningly loud. I put mine plus a 5hp air compressor in a 4x8' sound insulated closet.

I have no experience with a conventional single-stage dust collector. Before I built this shop I used a big shop vac which didn't collect much.

JKJ

[Justin Rapp]

Bryan,

I just went through an upgrade to my DC system, going from a single stage 1hp bag unit that I rolled from machine to machine to a cyclone. So the above posts already provide the benefit of going to a cyclone, and now that I have a cyclone, having the benefit of 2 stage collection really helps keep the air flowing rather than deal with a clogged machine.

In your research you will find that the claim is the longer the cyclone the better the separation. This is well known and if you do ultimately go with a shorter there are some tricks to getting better separation. What I mean about a shorter cyclone, those are typically the models mounted on a base with wheels, such as Jet, Laguna, some of the Grizzly models, etc.

So, what determines your HP needs. Honestly, the primary reason is how many tools you will be running at the same time. If you are a 1 person shop and have blast gates at each tool, your going to focus the suction to the one tool in use. If you are going to be running 2 or 3 of those tools at the same time, than you will need to step up your hp.

The second need to step up to more HP is to the length of your duct runs. If you can put your DC in a location that would have the shortest duct runs to your machines, the less HP you will require. Duct planning is just as, if not more important than the actually dust collection machine.

So, to give you an idea, my shop is a little smaller than yours and I run:

10" contactor saw (blocked up to get as good of dust collection as I can)
13" planer
6" jointer
14" DC (with two dc ports)
router table
miter saw
drill press

I am using a 3hp Laguna and have been very satisfied with the DC I am getting from it. All of my ducting is 26G smoke (aka vent) pipe (some call it 26G hvac ducting but it's actually for the venting side not hvac air supply) and holds up well and cost me under $400 including tape, hangers, duct mastic etc. I would suspect it would hold up to a 5hp unit as long as you keep 1 blast gate open. I did do a collapse test and my dc didn't collapse my ductwork.

Also, why do you want 2 floor sweeps? Sweeping the floor causes fine dust to get airborne and with good dust collection your big chips should mostly get pulled into the cyclone. A much healthier option to get floor dust is to use a wet dry vac with a hepa filter in it to suck up and trap the sawdust that does make it to the ground.

So you do have options before dropping $8000+ on a unit and the ducting. Do your research and planning before dropping the $$$.

[glenn bradley]

A single stage collector has almost double the CFM rating for round about half the price of a cyclone of the same horsepower. I don't quite understand the advantage of spending the extra money for a cyclone if it moves less air?

I need to jot this down so I can just cut and paste this response ;-) Not that your thread is trivial, it is not. The question comes up a lot. A single stage will move more air due to the cyclone or other separator not being in the path. Separation takes effort. If you can vent all of your spoil outside a single stage is the way to go. If you have to return your air into your work area . . . the reasoning becomes clear.

- If you have to breathe your return air, you need really good filtration.
- A cyclone keeps your really good filter from clogging annoyingly often.

So there you go, easy-peasy. If your air comes back into your shop, you want a cyclone and very good filtering. If you can vent all your spoil, you want a single stage.

To the 5HP recommendation, yes a 5HP cyclone with the proper fan and filters will give you the performance you should have in a home shop in order to protect your health at our current state of technology. This is just science and math, not a philosophical discussion. As we move away from that model to what we can afford, fit or otherwise deal with we must augment our dust collection with personal protective gear to varying degrees. I am going to try to milk a few more years out of my 2HP cyclone by super-tuning my duct path in the new (not yet built) shop. I am going in knowing I may not succeed or that the required add-ons of mask, fans, ambient cleaners, whatever may be more than I want to deal with. The out-building for the DC will be physically and electrically adequate for a 5HP upgrade should it come to that.

This does not mean "5HP or else". That is the current healthy recommendation. How close you have to get to that model is up to you, what you do, how often you do it, if you have kids, if you're a Capricorn and who knows what else. My point is, you want the best dust collection you can afford but, I would cut back a bit rather than go without a jointer if you get my drift ;-)

[David Walser]

Glenn -- I agree with everything you said. I just want to caveat your conclusion that, "If you can vent all your spoil, you want a single stage." Few of us can vent all our spoil if that includes the chips and larger pieces of sawdust. Quickly, we'd have a large pile of chips on the outside of the shop. Single stage collectors generally have a type of separator that allows the chips and larger particles of dust to fall into the collector bag while the air flows out the filter (and the smaller particles are trapped by the filter). However, for these separators to work as designed, something needs to slow the air steam, allowing the larger particles to fall out of the air and into the bag. The filter performs part of this function. So, venting a single stage DC will, almost inevitably, result in a lot of chips and sawdust being dumped outside the shop. So, yes, you can do it. And if you can, it will work well. Just be prepared for a mess.

Another reason to go with a cyclone over a single stage machine is the cyclone separates out the larger items before they can hit the impeller. Impellers are pretty durable, so generally there is no harm done by allowing something large -- or metal -- to hit the fan. However, the large bang it makes can be startling! No damage may have been done the the machine, but you might need to change your pants...

[Bryan Solomon]

Wow! What a huge amount of advice in such a short period of time. Thanks so much.

Sounds like you guys have me sold on the cyclone. The clearvue seems to be the most power for the money. I will be calling them and asking the same questions that I asked Oneida a few weeks back. Now for the next question...putting the cyclone in a closet or a neighboring structure: I plan to have room to build another storage room connected to the garage on the back side of it (maybe 10' x 7'). It will have separate door to the outside and will be separated by the exterior wall of the garage. This will be room to store my yard tools, lawn mower, and potentially dust collector. My question is in regards to the suction from the dust collector. If the cyclone is located in this room, do I need to put a large transfer grille between the garage and this room? How much air needs to be available for the cyclone to run?

[Jim Becker]

My cyclone (and compressor) are in a sound abated closet and I wouldn't have it any other way. It makes a significant difference in overall sound level. And yes, you do need to return air back to the shop if you are not venting outside. But...it should not be a "grill". It needs to be an indirect path or you'll just be dumping the noise back into the shop. A baffled hard path like I use up between the joists or even some of the flexible HVAC duct that meanders a little (like John Jordan uses) will do the trick. And the overall area of the return to the shop needs to be equal to or preferably larger than the outlet from the cyclone to the filters.

[John K Jordan]

My cyclone (and compressor) are in a sound abated closet and I wouldn't have it any other way. It makes a significant difference in overall sound level. And yes, you do need to return air back to the shop if you are not venting outside. But...it should not be a "grill". It needs to be an indirect path or you'll just be dumping the noise back into the shop. A baffled hard path like I use up between the joists or even some of the flexible HVAC duct that meanders a little (like John Jordan uses) will do the trick. And the overall area of the return to the shop needs to be equal to or preferably larger than the outlet from the cyclone to the filters.

I've read reports from people who said they used the insulated flexible HVAC duct for exhaust but I've never tried it. The insulation is supposed to work like a muffler to reduce the noise.

I built a baffled return duct with the bulk up above the ceiling between two trusses from my closet. I did put a grill and HVAC filters on both ends of the duct but after maybe 6 years of use haven't seen any dust collected on those. This was my working design sketch of the duct, built from 1/2" plywood, sprayed with rubber inside, insulation stuffed around it in the ceiling:

450662

Putting it in an outside closet attached to the shop might be even quieter than mine, which is pretty quiet. I'd hang the cyclone on a non-shared wall to reduce direct sound transmission.

JKJ

[John C Bush]

Hi Bryan,
Congrats on the new shop. A cyclone in an attached structure is a great way to go. I have a 2ph Griz cyclone in an attached shed--vent outside with no return air-- and it has worked very well for me. Main 7" run is 30' with 6" branching to 4" drops. HVAC snaplock with brush-on duct sealer on pop-riveted joints and fittings. I had floor sweeps but never used them. I'll send you mine if you want to try them. The 2hp handles a 20" planer, 12" jointer, 25" drum sander, TS, BS, etc , just fine so not sure if 3hp is needed. Maybe with the HEPA filters 3hp would be better/needed. Noise level is fine for conversation and managing chip barrel from an outside door is easy as well. Good luck shopping.

[Tom Dixon]

Hi Bryan,

My shop is similar in size to yours. Mine is 24'x36' with 10' Ceilings. I ended up buying a Grizzly G0442 5 HP Cyclone Dust Collector and put in Spiral Pipe. I used an an 8" main and 6" branches which I reduced to 4" or 5" at the machine if necessary. I built a separate 5'x8' insulated exterior shed for the cyclone with filtered returns. Not including the shed I spent about 6K, 3K for the cyclone and 3K for the spiral pipe and fittings, with the majority of the piping cost being the number and types of fittings. The shed allowed me to raise up the cyclone so that the 8" pipe is about 2 " from the ceiling so it's out of the way. I am very pleased with the result. Regardless of what brand you choose, go with the cyclone and if you can put it in a closet or a shed it will definitely reduce your noise. A shed saves on internal floor space as well.

450733

450737

450739 450738

[Jim Becker]

I've read reports from people who said they used the insulated flexible HVAC duct for exhaust but I've never tried it. The insulation is supposed to work like a muffler to reduce the noise.

Did I "mis-remember" what you were using? If so, my apologies. I thought you did the flexible stuff snaking around your rafters for your return...

[Justin Rapp]

Hi Bryan,

My shop is similar in size to yours. Mine is 24'x36' with 10' Ceilings. I ended up buying a Grizzly G0442 5 HP Cyclone Dust Collector and put in Spiral Pipe. I used an an 8" main and 6" branches which I reduced to 4" or 5" at the machine if necessary. I built a separate 5'x8' insulated exterior shed for the cyclone with filtered returns. Not including the shed I spent about 6K, 3K for the cyclone and 3K for the spiral pipe and fittings, with the majority of the piping cost being the number and types of fittings. The shed allowed me to raise up the cyclone so that the 8" pipe is about 2 " from the ceiling so it's out of the way. I am very pleased with the result. Regardless of what brand you choose, go with the cyclone and if you can put it in a closet or a shed it will definitely reduce your noise. A shed saves on internal floor space as well.

450733




Now that is one impressive workshop!!!

[John K Jordan]

Did I "mis-remember" what you were using? If so, my apologies. I thought you did the flexible stuff snaking around your rafters for your return...

I don’t remember the exchange but do remember reports on the Clearvue forum from others who used flex to exhaust outside and perhaps for return. My aging brain is increasingly unreliable!

The only places I use flex is from my HVAC unit to the diffusers spaced around the shop. With poetic license I guess I might describe my baffled plywood return duct as "snaking" through the trusses but that would be one rigid snake. :D

BTW, the most challenging part of planning and executing my DC design was fitting the 6” feed ductwork down through the ceiling inside the 4x8’ by 9’ high closet and running the dicts through the trusses with a 40’ branch of a 25’ straight main, all without trimming even a sliver from a truss. Almost like playing 3d chess! I drew pages of plans.

For anyone else facing fitting the cyclone in a closet: I first drew an outline of the closet on the shop floor and set the partially assembled cyclone upside down and blocked it up to allow for the distance to the ceiling with space for the motor/impeller. After jockeying the cyclone into the best position I made cardboard cutouts to represent the lengths of ducts and the types and angles for the couplers needed then drew a template which I layer used to cut the ellipse needed in the closet ceiling. The actual installation went smoothly without any head scratching. I used a short piece of flex at the inlet to allow easier disassembly if ever needed.

I DON’T have the recommended 6’ straight inlet duct directly into the cyclone and have a couple of other bends that would make a purist cringe but the 5hp is so powerful I can’t detect any inefficiency. The thing has incredible flow and separation and from examining the inside through the clean-outs I don’t see any sign of dead spots - all ducts are clean. In my thinking that’s an argument for going bigger than the minimum.

JKJ

[Thomas Wilson]

Wow! What a huge amount of advice in such a short period of time. Thanks so much.

Sounds like you guys have me sold on the cyclone. The clearvue seems to be the most power for the money. I will be calling them and asking the same questions that I asked Oneida a few weeks back. Now for the next question...putting the cyclone in a closet or a neighboring structure: I plan to have room to build another storage room connected to the garage on the back side of it (maybe 10' x 7'). It will have separate door to the outside and will be separated by the exterior wall of the garage. This will be room to store my yard tools, lawn mower, and potentially dust collector. My question is in regards to the suction from the dust collector. If the cyclone is located in this room, do I need to put a large transfer grille between the garage and this room? How much air needs to be available for the cyclone to run?
A rule of thumb for the return that I have read is three times the area of the dust collector’s inlet pipe. That would lower the velocity by a factor of nine and pressure losses proportionately. If you wanted to put a grill or filter in the return path, you will raise the pressure in the shed causing the return air out of any leaks in the shed.

[Steve Wurster]

I DON’T have the recommended 6’ straight inlet duct directly into the cyclone and have a couple of other bends that would make a purist cringe but the 5hp is so powerful I can’t detect any inefficiency. The thing has incredible flow and separation and from examining the inside through the clean-outs I don’t see any sign of dead spots - all ducts are clean. In my thinking that’s an argument for going bigger than the minimum.


Being in a basement shop with low ceilings and existing HVAC ducts, there's no way I could ever get that straight shot of duct off the cyclone. I've been researching and planning for the eventual replacement of my system, and no matter what I come up with I would almost certainly have to start with a 90 degree bend up to the ceiling / joists. Any other plan simply gets in the way of the things I already have in my shop and on the walls (and lighting on the ceiling), and it's a bit tough to rearrange that much, although it might be doable.

That height limit means something like the Oneida Dust Gorilla Pro (with 35 gallon drum) might just barely fit in the shop, with the motor just eking up between the joists. However for me to go with that unit I would have to put it on the edge of my shop, closest to the finished side of the basement, and underneath my foyer / dining room. The noise from that unit might be too much, although for sure the 5HP model should compensate for the fact that I would still have to start with a 90 degree bend.

The other issue I have to deal with is electrical. My current DC is 20A at 120V. I have space in the sub-panel to turn that into 20A at 240V. However both the 3HP and 5HP Dust Gorilla Pro require a 30A breaker. That might be harder to swing, as not only does it require running new wiring, but the increase in load means I potentially run the risk of drawing more than that sub-panel can support. Although that risk is very low in reality, especially since even the 5HP model has a listed full load of 18-23A.

I've also been looking at the Oneida V-3000. That unit is smaller (fits under my joists no problem) and requires only a 20A breaker. But, again, I would still have to start with a 90 degree bend and I wonder how well that would perform in that situation compared to the Dust Gorilla Pro. Plus whenever we decide to move the plan is for me to have a larger shop space, so in theory I run the risk of having an under-powered unit in that space if I go with the V-3000.

Of course I recently did some rework on my current system, so I have to run with that for quite a while longer before seriously thinking about upgrading.

[Michael W. Clark]

I would also agree that the 2-stage with cyclone is preferable if you have the space and budget. In whichever system you buy, I would suggest you get as much filter area as possible. I'm not a fan of the cartridge filters for the typical home/hobby setup. They put the dust on the inside where the pleats are the narrowest, making it very difficult to clean well. I know from sizing collectors, we go ~3X the filter area for a cartridge to get the same performance for a bag and that is with the dust on the outside. If the dust is on the inside, you need even more area, maybe 5-6X+ that of a bag area IMO.

For filtration rating, there was a long thread about that here a few weeks ago. Regardless, the filtration rating claim, it is only as good as the fabric. Bag filters typically use a felted fabric such as polyester felt. It is generally 99%+ @ 2 micron. You can get other fabrics that are 99.5% @ 0.5 micron such as PTFE coated polyester felt. There are companies that make custom filters for home units and I hear they are reasonably priced. If you get a cloth fabric, it has to be seasoned and/or keep a dust cake on it for best performance. A felted filter does not need a dust cake to perform as rated.

I have seen several large single stage units in commercial shops. Delta, Dustex, Agget, Dantherm, and others make them. I've seen them up to 20 or 30HP, especially pulling from a CNC where you may need high SP at the hood. The open single stage units are desirable to keep duct costs down and so they can locate them inside without NFPA concerns (most are under 5000 CFM and are enclosureless). A cyclone over 8 ft3 in volume is subject to NFPA 68 if the shop is required to comply. Larger systems may use a high efficiency cyclone only, a baghouse only, or a combination of standard efficiency cyclone and baghouse.

My ideal setup would be a high efficiency cyclone discharging into a set of bags. The fan would be installed after the cyclone and blowing into the bags. This would be located in a dedicated room or bump out with doors between the shop and the room. In the doors, a 2-stage panel filter arrangement with a coarse filter for the 1st stage and a pleated high MERV or HEPA for the second stage. The panel filters and bag filters on the collector unit are relatively inexpensive and easy to change, especially compared to a blinded cartridge filter.

[Michael W. Clark]

I DON’T have the recommended 6’ straight inlet duct directly into the cyclone and have a couple of other bends that would make a purist cringe but the 5hp is so powerful I can’t detect any inefficiency. The thing has incredible flow and separation and from examining the inside through the clean-outs I don’t see any sign of dead spots - all ducts are clean. In my thinking that’s an argument for going bigger than the minimum.

JKJ

Hi John, for most single cyclones, the main thing is not to have a horizontal elbow on the inlet that is turning the opposite rotation of the cyclone. For example, if your cyclone is CW rotation, you don't want an elbow that induces a CCW rotation close to the inlet.

Or, if you had two cyclones in parallel (sitting side by side, each handling half of the airflow), you would want some straight so each cyclone saw a balanced airflow and dust loading. A horizontal elbow in this situation would unevenly load one cyclone and could cause plugging.

[Michael W. Clark]

A rule of thumb for the return that I have read is three times the area of the dust collector’s inlet pipe. That would lower the velocity by a factor of nine and pressure losses proportionately. If you wanted to put a grill or filter in the return path, you will raise the pressure in the shed causing the return air out of any leaks in the shed.

Hi Thomas, I think you may have meant the pressure instead of velocity? Velocity changes linearly with duct area, but the pressure varies with the square of the velocity change (or with flow for a constant area).

I think most HVAC systems are designed for around 1500-2000 FPM in the ductwork? The critical things for register selection is the "throw" of the air out of the register and the noise. There are some catalogs (maybe some electronic tools) that suggest the register size depending on your anticipated flow. I haven't done much HVAC system design so sorry I can't be of more help. Its a little different game than dust collection system design but still follows some similar principals.

[Bryan Solomon]

Hi Bryan,

My shop is similar in size to yours. Mine is 24'x36' with 10' Ceilings. I ended up buying a Grizzly G0442 5 HP Cyclone Dust Collector and put in Spiral Pipe. I used an an 8" main and 6" branches which I reduced to 4" or 5" at the machine if necessary. I built a separate 5'x8' insulated exterior shed for the cyclone with filtered returns. Not including the shed I spent about 6K, 3K for the cyclone and 3K for the spiral pipe and fittings, with the majority of the piping cost being the number and types of fittings. The shed allowed me to raise up the cyclone so that the 8" pipe is about 2 " from the ceiling so it's out of the way. I am very pleased with the result. Regardless of what brand you choose, go with the cyclone and if you can put it in a closet or a shed it will definitely reduce your noise. A shed saves on internal floor space as well.

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Your shop looks great! Couple questions:

How did you draw this up? Is this sketchup?
I like your overarm dust collector. Who makes it?
I dont see any cords for machines in the middle of your shop. Do you have a receptacle in the floor for your table saw, or is the cord coiled up for the picture?
Looks like you have 2 transfer grilles between the dust collection shed and your shop. And then another baffle on the outside of the dust collection shed. So when the dust collector is running, its drawing conditioned air from inside your shop and pushing it out through both the baffle in the exterior wall of the shed and through your 2 transfer grilles, correct?

[John K Jordan]

Hi John, for most single cyclones, the main thing is not to have a horizontal elbow on the inlet that is turning the opposite rotation of the cyclone. ...

My inlet duct is in a straight line when viewed from the top but a slight bend upwards from the inlet and another slight bend further up towards the ceiling. Seems to work OK.

[Michael W. Clark]

My inlet duct is in a straight line when viewed from the top but a slight bend upwards from the inlet and another slight bend further up towards the ceiling. Seems to work OK.

Yes, generally elbows in the vertical are not a problem either.

[Jim Becker]

Being in a basement shop with low ceilings and existing HVAC ducts, there's no way I could ever get that straight shot of duct off the cyclone. I've been researching and planning for the eventual replacement of my system, and no matter what I come up with I would almost certainly have to start with a 90 degree bend up to the ceiling / joists. Any other plan simply gets in the way of the things I already have in my shop and on the walls (and lighting on the ceiling), and it's a bit tough to rearrange that much, although it might be doable.

Steve, don't mix up "optimal" with "usable". Even if you have to compromise the duct path a little to fit the machine in your shop, a decent cyclone will still benefit you. With a little creativity in location you may still be able to straighten that last few feet up a little, too. I'm only able to partially picture in my mine how your joists and beams run, but when the time comes, I'm happy to help you with things.

Alternatively...you can buy our house and my shop when the time comes. :) We're looking for what comes next "as we speak". LOL

[John K Jordan]

...
Alternatively...you can buy our house and my shop when the time comes. :) We're looking for what comes next "as we speak". LOL

Check out TN. It's warmer. :) And the growing and active honeybee season is a bit longer. My gardener brother in Ohio said we have almost two more months of growing season.
And the real estate prices away from the cities can be unbelievable. Our 27 acres with timber frame house and old farm outbuildings was less than the average subdivision house on the outskirts of Knoxville.

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JKJ, PA expatripate

[Jim Becker]

Check out TN. It's warmer. :) And the growing and active honeybee season is a bit longer. My gardener brother in Ohio said we have almost two more months of growing season.
And the real estate prices away from the cities can be unbelievable. Our 27 acres with timber frame house and old farm outbuildings was less than the average subdivision house on the outskirts of Knoxville.

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JKJ, PA expatripate

Thanks, but we're staying local for a number of reasons, including Professor Dr. SWMBO is still employed for 3-5 years unless there's an amazing offer extended and because of the need to provide local support to our older daughter, who while living "independently" in town, isn't really fully independent. If the stars align, we may have a solution that's two minutes from her apartment and five minutes from the train station.

We now return you to our regularly scheduled "single stage vs cyclone" extravaganza!

[glenn bradley]

Being in a basement shop with low ceilings and existing HVAC ducts, there's no way I could ever get that straight shot of duct off the cyclone. I've been researching and planning for the eventual replacement of my system, and no matter what I come up with I would almost certainly have to start with a 90 degree bend up to the ceiling / joists. Any other plan simply gets in the way of the things I already have in my shop and on the walls (and lighting on the ceiling), and it's a bit tough to rearrange that much, although it might be doable.

I was faced with this even though I am building a new building. Getting the straight shot caused problems of one sort or another with every workable option. After a few consults with folks who do such things for a living we came up with a large sweeping "S" as my best alternative.

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I'm told that the straight shot is primarily for separation optimization through the reduction of turbulence at the inlet to the cyclone ramp. Given that my post-separator flow will vent outside (no filter) a bit of a loss in the 'separation' variable among those that I had to choose from was the best option for me.

There is always give and take. Even when you are designing from the ground up. I won't bore everyone with all the variables that we went through only to be tripped up by one thing or another. The important thing is that you get the best solution that your situation will allow. Take it from me, you can analyze to the point of paralysis. I'm not saying that you shouldn't give it a thorough analysis and your best effort. Just don't beat yourself up once you have found your best solution.

[Jim Becker]

Steve's basement shop has some not-unexpected construction features at the ceiling level including beams and ductwork. 'Nature of the beast, unfortunately. But he'll figure out a solution!

[Steve Wurster]

Steve, don't mix up "optimal" with "usable". Even if you have to compromise the duct path a little to fit the machine in your shop, a decent cyclone will still benefit you. With a little creativity in location you may still be able to straighten that last few feet up a little, too. I'm only able to partially picture in my mine how your joists and beams run, but when the time comes, I'm happy to help you with things.

Alternatively...you can buy our house and my shop when the time comes. :) We're looking for what comes next "as we speak". LOL

Ha ha! Do all the tools that are currently in your shop come with it, you know, thrown in for free? Ha ha! Actually, the plan is for us to eventually move to an old farm house on my in-laws' property (on Burnt House Hill road, btw). There's a house, a large barn, and a nice garage, all of which were completely remodeled recently. However, we would want to keep our cars in that garage, so plans were already drawn up to build a shop next to the garage. That shop would have a floor plan of ~17x33, which in all reality isn't much larger than the shop side of my basement. However, it would not only be at ground level but also have a higher ceiling, no HVAC equipment in the middle of it, and have a small offset section that would perfectly fit a nice dust collector. It also wouldn't need to store all the extra "stuff" that's otherwise taking up space in my current basement. Of course we don't know when we're going to move there, but since it won't be anytime soon (maybe 10 years or so), no work has started on the shop itself. In the meantime, I'm jammed into my basement.

My current shop is ~16x22, with the joists running parallel to the 16' wall. The bottom of the joists are ~93" from the floor, so I do have some room above that to squeeze in the motor of a larger cyclone. However, about half of that ceiling space has HVAC ducts (returns, mostly), and of course there's a good bit of wiring and lighting in the open areas (all lights are standard LED bulbs, not tubes). My DC is currently located in the middle of a 22' wall; it's mounted to the wall with 5" piping coming out of the SDD perpendicular to that wall, with one route going up and one going down. The up route goes along an amazingly open joist and then down the other side to a hose. The down route goes into my table saw that sits directly next to the DC (that is, the right side of the saw is basically up against the DC "area").

For future DC placement I have two ideas in mind. The first is to put it where the DC is right now. I would almost certainly have to shorten the lumber rack that hangs next to the DC, but that's not a big deal. In this scenario I'm thinking I would have the inlet run parallel to the wall with the piping bending upwards and then rotating parallel to the joists; I could then run lines from there (including a drop back down for the saw and hopefully an overarm pickup). The other option I'm thinking of is putting the DC at the far end, past the lumber rack. That's effectively "outside" the shop proper, and would replace a shelving unit that currently sits in that location. However, there's more vertical space there thanks to less wiring in the way, and there's more room for the filter stack. However, it's further away from all tools, would get in the way slightly, and would require the piping and filters to block some access to part of the lumber rack (perhaps not that big of a deal). In that scenario I might have to consider a more powerful DC, but that adds to the noise, and that location is under the foyer / dining room.

But... since we're not moving anytime soon, do I really need to "overbuy" now (or within the next year or so) or could I get away with a good system that would almost certainly work well for the space it's in? Then when we move I could always upgrade to something that would definitely work well in that larger space (and have a much easier time running ductwork!).

[Jim Becker]

I just drove down Burnt House Hill Road today, Steve. :) I've always appreciated many of the properties along there, although that "yuge" mansion that was recently built is a bit gaudy and out of place, IMHO. But WHY would you want to park cars in a shop, err....garage? That's just not acceptable. LOL

Good decision to buy your "last" DC now. It will not hurt it "loafing" in a smaller shop and you'll know it will be adequate if you get to expand or spread out in the future.

[Steve Wurster]

I just drove down Burnt House Hill Road today, Steve. :) I've always appreciated many of the properties along there, although that "yuge" mansion that was recently built is a bit gaudy and out of place, IMHO. But WHY would you want to park cars in a shop, err....garage? That's just not acceptable. LOL

Good decision to buy your "last" DC now. It will not hurt it "loafing" in a smaller shop and you'll know it will be adequate if you get to expand or spread out in the future.

You might be talking about that place on Almshouse...

Anyway, for right now I'm not buying anything (or at least not a DC, lol). I've got to see how my recent "updates" perform over this year before thinking about an upgrade.

[Jim Becker]

You might be talking about that place on Almshouse...

Nope...I think the one on Almshouse is Pink's parent's place, but I could be wrong about that. The one i mentioned is a new on on Burnt House, on the right side going north-west where the road dips down and back up sharply with the narrow bridge.

[Steve Wurster]

Nope...I think the one on Almshouse is Pink's parent's place, but I could be wrong about that. The one i mentioned is a new on on Burnt House, on the right side going north-west where the road dips down and back up sharply with the narrow bridge.

Oh, is that who owns that place?! That place is definitely gaudy. lol

And, well, that newer place on Burnt House you're mentioning is my in-laws' place. LOL I don't find it gaudy, but it definitely stands out compared to the other properties around it. The farm house is immediately before it on the right, at the peak of the hill before the narrow bridge.

[Tom Dixon]

Your shop looks great! Couple questions:

How did you draw this up? Is this Sketchup?
I like your overarm dust collector. Who makes it?
I don't see any cords for machines in the middle of your shop. Do you have a receptacle in the floor for your table saw, or is the cord coiled up for the picture?
Looks like you have 2 transfer grilles between the dust collection shed and your shop. And then another baffle on the outside of the dust collection shed. So when the dust collector is running, its drawing conditioned air from inside your shop and pushing it out through both the baffle in the exterior wall of the shed and through your 2 transfer grilles, correct?





Yes. I have my full shop drawn in Sketchup. I started it 4+ years ago to build it and have just kept adding to it for machine layout, dust collection and so on. The file is now over 200MB so 4 times the max size you can upload to the 3D warehouse. I'm updating a few things on the drawing at the moment, but I keep a downloadable copy for people that are interested and or want to use some of the parts for their own shop layout. http://www.teetomterrific.com/downloads/shop/Workshop_Master.skp It takes a few minutes to open because it's so huge.
The cord on the Unisaw is coiled up. To plug it in it is about 7 feet along the floor. I keep it coiled when I'm not using the saw. My 220 plugs are L6 locking. All my electrical outlets are along the walls. Wiring is run in 1" conduit up t the attic and along the trusses outside the attic storage area so I can change easily get to it if I need to change it.
There is no outside baffle in the DC shed. Just a small sealed window. I do get some leakage through the roll-up door but not a lot. Mostly I think I need to put in third return filter grill, (with Merv 12 filter), below the two existing ones to reduce the pressure in the shed to eliminate what leakage I do have. When I run it for a long time my heater kicks in more often. I will probably add that third filter grill this summer and add some baffling in the shed to further reduce the noise. https://www.amazon.com/gp/product/B0061MKY5M https://www.amazon.com/gp/product/B07CV3TDSH

[Jim Becker]

And, well, that newer place on Burnt House you're mentioning is my in-laws' place. LOL I don't find it gaudy, but it definitely stands out compared to the other properties around it. The farm house is immediately before it on the right, at the peak of the hill before the narrow bridge.

https://snz04pap002files.storage.live.com/y4mGNxo47Ef9MBZ2z0Z3F9pyUueOWQgvZ4EP6m069sJpBFpJ60 n_yXyzFsa9fMvfxO9b7zZdcShHewJ2lWwW2odDLJBMVlkwfRp6 xb8Oxh0srqYpxIAPFMup1KWK1CZa7sl-ddj3HAQqcxYtnk6PHK_QdN-gT6vz4hXbbRIM8JTBvF5eyobPn7XQMHRCTGekUBK?width=314&height=425&cropmode=none

I guess I owe you a beverage or three to make up for that. LOL

[David Walser]

It's okay to find your in-laws' house and things gaudy. Their primary role in life was to properly raise your future bride. (I've done that well with my two daughters. Anyone willing to take them off my hands?) If they've given you a good wife, cut them a whole lot of slack all the other areas of their life. They've earned it!