# Central dust collection advice



## nerdbot (Sep 3, 2014)

Hi all,

I've acquired enough power tools now that pulling around my shopvac/dust deputy cart and moving the hose every time I switch tools is becoming tiresome (when I remember to move the hose, that is). It's now to the point where I want to get more serious about centralizing my dust collection setup.

When I started my slow process to upgrade and organize my garage a couple years ago, I created a SketchUp model of my garage to help me visualize the things I was adding. So here's what I was thinking for my dust collection setup:










Items labeled in the diagram:
A - Most likely where my vac will go
B - Garage door openers
C - Jet air filter
D - Pull-up bar
E & F - Cabinets
G - Fluorescent lights (all the yellow bars)

I currently have a drill press, table saw, miter saw, and lunchbox planer all on mobile cabinets I made. I also would like to hook up my sanders (ROS and disc/belt sander combo). I never use more than one tool at a time. Also, I don't necessarily need one blast gate per tool - swapping tools on a blast gate seems less of a hassle then constantly pulling the vacuum around. So, the numbered circles are where I'm thinking of putting dust ports:
1 - My tabletop drill press
2 - Bandsaw (hopefully getting one this year)
3, 4, 5, 6 - proposed locations for dust port/blast gates.

Because I built out my garage shop as my needs arose over, I didn't take in to account dust collection layout when I put in my fluorescent lights or my pullup bar… So everything in the picture except the light/bright blue dust collection pipes are already in place and can't really be moved. I outlined my primary work area with the dotted red line though on rare occasions I venture out further into the car bay on the far left.

According to the measurements in sketchup, I'm looking at approximately 30 feet from the dust collector to station 1's blast gate, my drill press. Then about 25-30 feet to station 5 and 6's blast gates, which would be on the ceiling and doesn't take into account the length of hose to attach to the tools.

I was leaning towards clear PVC pipes for my main runs along the ceiling and wall, but it looks like they only come, at reasonably affordable prices, in 2.5" diameter and I wasn't sure what diameter would be best suited to the motor of my shopvac. I currently have a Craftsman XSP 12006 shopvac on a cart with my Dust Deputy and an iVac switch. I purchased the 12006 about a year ago after seeing the comparison article in Wood magazine, but I couldn't find the CFM rating.

I'm comfortable running either 2.5" or 4" diameter pipe, but I don't think I have the ceiling clearance or space to run anything larger than that. If I went with 4" diamater pipe, I'd still prefer clear hose so I'd get the kind with smooth inner walls for better performance. I made sure to avoid any 90 degree turns - though I see the first turn I drew in sketchup is a 90 degree (from my drill press to the ceiling).

I don't plan on moving the vacuum itself very often. To clean up the shop, I may get one of those Rockler expanding vacuum hoses, or just sweep the dust to a nearby port and vacuum from there. So, while I'd prefer to stick with my shopvac for a little bit longer, I'm not opposed to switching it out for an inexpensive (i.e., Harbor Freight) dust collector that I can mount to the wall.

To start I'll use manual blast gates, but eventually will consider automatic ones or attempt some of the DIY arduino based solutions I've seen.

Any comments or advice would be greatly appreciated. Thanks!


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## wapakfred (Jul 29, 2011)

I wouldn't do that with a vac, consider getting a DC and at a minimum use 4" PVC. DO NOT put 4" PVC on a vac, they are made to work with the smaller diameter tubes. As for the lights, in my last shop I had to move them all to make way for the ductwork (shows important DC is to me, I guess). In the current shop, I laid out the ductwork first, then installed the lights….and they really have no organization other than they work well. In your case they don'y appear to interfer with what I think is a fairly clean layout, the only thing I would suggest (with 4" duct and a DC) is that you not use 90º els, instead go with a pair of 45º els, with a short piece of straight pipe in between the 2.


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## rwe2156 (May 7, 2014)

My suggestions:

In this size shop, you might consider a mobile DC in the 1000CFM range and run 4" flex to each machine, keeping machines clustered together.

Think about what your big chip producers are: (jointer, planer) and position accordingly.
Bandsaw, RAS are fine chip producers, therefore harder to collect.
Sanders are dust producers, hardest to collect.
I would consider keeping your shop vac for the sanders and drill press. Be sure to put a HEPA filter on it.

DC for a drill press is a challenge at best. I use my shop vac and just anchor the hose in a good spot.

If you go with pipes, I think 4" S&D pipe (thinwall) would work fine, but 6" is better for the mains if the DC is 900CFM or more.

Get the best filter you can in a closed shop like this.
When sanding or cutting MDF remember to wear a respirator!!

Good luck.


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## DIYaholic (Jan 28, 2011)

+1 on Fred's comments….
+1 on rwe2156's comments….

Unless you go with a large DC system (like a 3HP Cyclone), fine dust capture(at the source) will be difficult at best.
No DC will capture all the fine dust (the most dangerous), so an ambient air cleaner should also be used (which you have planned for). However, a quality respirator should also be used when making dust!!!
Collecting dust should incorporate a multifaceted approach.
1) DC for large chip/dust capture at the source. (jointer/planer, TS, BS, SCMS…..) 
2) Shop-Vac for fine dust at the source. (ROS)
3) Ambient air cleaner for fine dust air filtration.
4) Quality Respirator to maintain healthy lung function.

You should consider Wynn Environmental for a canister filter, for whatever DC system you get.
I have the infamous HF 2HP DC, so I went with their 35A274NANO Cartridge Kit.


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## Crank50 (Jan 31, 2014)

2 1/2" pipe is OK for a shop vac. Certainly no larger. 
A shop vacuum produces high pressure at a small volume.
The small volume of CFM, most likely less than 100 CFM, will not have enough velocity in a large pipe to keep the dust and chips entrained in the flow. So they will settle in the pipe and eventually block it.

The vac will work fairly well for things like a drill press, a small 9" or 10" band saw, a router or a disk sander.
The best jobs for a shop vac are with small pipes where the high pressure will create the high velocity needed for close capture of fast moving chips and dust. A router is a perfect example of this.

For bigger tools like a table saw, jointer, planer, miter saw, or drum sander you will need a dust collector with much more volume of air. Things that need a larger hood, like a miter saw, are good example of this.


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## nerdbot (Sep 3, 2014)

Thanks for all the responses! Though they did create a few more questions… But first, from what everyone has said, I think I would modify my plan as follows:

1.) Keep my current mobile shop vac/dust deputy setup for things like my drill press, sanding, and shop cleanup but maybe downsize the vacuum to save a bit of space

2.) Eliminate the duct run to the drill press entirely since I'll be using the shop vac for dust collection there. I don't use the drill press all that often anyway.

3.) Go with 4" pipe of some sort for the remaining dust collection ducting, and use that for my bigger tools (table saw, planer, miter saw, band saw)

With less overall ducting, I think I might get the smaller 1HP 13 gallon HF unit and pick up another dust deputy to put in front of it. Looking at some of the estimated CFM numbers I'm seeing on the internet for the various tools, the 660CFM on that HF DC seems to be sufficient enough for big tools except maybe my planer (Dewalt DW735)?

When I tried putting larger containers under the dust deputy with my shop vac (Brute garbage cans from HD and fiberboard drums) I noticed that the shop vac was strong enough to collapse the containers if there was even minor blockage in the hoses. Is that because of what Crank50 was saying about the high pressure/small volume nature of shop vacs? Does that mean I might be able to use those "flimsier" containers when I switch to a true dust collector because they don't create as much high pressure?

Also, is it ok to use 4" clear flex hose for the duct runs as long as the interior is smooth to improve air flow? Or should I really be using solid PVC pipes? I like the idea of being able to see the dust moving not only from an aesthetic perspective, but it's also a visual reminder that I have my DC on and connected to the tool I'm currently using. I wear hearing protection 99% of the time so I can't always hear if the shop vac is on and sometimes find I forgot to switch the iVac switch to "auto on/off" until after I finish the cut and see a pile of dust on the floor…

As far as my air filter unit, I already have that in place. I found posts quoting the same source for air filter unit placement guidelines, and I placed it as best I could according to those guidelines, but I was still unsure of orientation of the intake/outtake. Currently in my diagram above, the clean air exhaust points to the left side of my garage (towards the pullup bar) and the intake is nearest the right side wall. I read that the exhaust should point in the area I will be standing most often, which makes sense since I want to be breathing the clean air. On the other hand, following those guidelines as I understand them has the intake pointing at an area that basically generates no dust and rely on air circulation to circulate the dust from my tools towards the intake. Is that ok?

It's funny that you guys mention the respirator. I always wear a respirator when in the garage for more than 5 minutes, because I learned early on that if I don't, I'll be congested for the next day or two and maybe even have a scratchy throat. Doesn't matter what kind of wood or material I'm working with, even if I'm not actively working but just stirring up the dust by moving around the garage. Maybe if I had known that about myself before I got started with woodworking, I would've never gone down this path… 

Thanks again so much for all the advice, and sorry for the length and amount of questions. Still so much to learn!


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## wapakfred (Jul 29, 2011)

My take on some of the questions: Skip that HF unit. The smallest from them that is usable (IMHO) if the "2 HP" one. It's actually closer to 1.5 HP, but is still pretty economical and should serve you well. The CFM numbers on most DC's are no more correct than the 6.5 HP your shop vac has. In most cases you can plan on getting about 1/2 what they say, sometimes less. To save more money, skip the dust deputy and build a Thein separator (search for that). Not too hard to build and works very well. I've not seen clear smooth wall flex hose, but I'll bet it's more expensive than 4" PVC. As for the air filter, they are very good to have, and perfect placement is not always possible. Stay with what you have, but don't forego the respirator because of the auir filter. By the time the filter gets the dust, it's already in your lungs. They do help with overall cleanliness (even a world class DC doesn't get everything) and that's important. The need for the clear hose is puzzling….I suspect that after a short time you won't be able to see anything moving in there anyway. Set your self up with a remote for the DC, I think shortly using it will be second nature.

Forgot to mention: that HF unit (and probably the smaller one as well) will need a filter upgrade, the OEM bags just aren't tight enough (adding to the overall cost)


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## DIYaholic (Jan 28, 2011)

+1 on what Fred just said.

Look for HF 2HP DC modifications/upgrades here on LJs for ideas….
Likewise, do a search for Thein seperator/cyclone for more ideas….
I used a metal 30gal trash can for my collection build.
BTW: You can't order online from Wynn Environmental (35A Cartridge filter).
You have to call to place an order. They are a pleasure to deal with!!!


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## Crank50 (Jan 31, 2014)

I can confirm the small 1hp HF collector is not so good and is very noisy to boot. It has a universal motor (not induction) that is a screaming demon. The 2hp HF collector is only about $50 more than the 1hp unit anyway. The 2hp unit will handle two dust sources at once as long as you can capture them both with a 4" duct and a 2 1/2" duct.

I wish I could understand the mindset of everyone wanting to put a cyclone in front of their dust collectors. An expansion chamber makes perfect sense to let the bulk of the big stuff drop out of the flow, especially when installed near the dust source. This reduces the need to empty the plastic bag on the filter by about 90% and it prevents chunks, screws and nails from going through the fan.

But, a true cyclone does not collect any more fine dust than a good filter cartridge on the dust collector. There is no increase in air flow either; just the opposite, because the cyclone reduces the static pressure you have available at the dust sources to capture dust in the first place.


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## JeffP (Aug 4, 2014)

I have noticed a trend. It might be sensible, but I would like to question it.

As a woodworker's shop increases in size and how many dust-makers he owns, the belief seems to be that the ultimate dust solution is a HUGE dust collector with lots of expensive ductwork.

What about two or three smaller units dedicated to each of the primary dust-makers?

Total cost is probably lower and it seems like the space and installation might favor the two or three smaller units with almost no ductwork.

Have any of you "done the math" on this to figure out if the HUGE system is really better or cheaper than a "satellite" system?


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## English (May 10, 2014)

I see a lot of notations to CFM. CFM is the result of a negative static pressure. The static pressure rating of your DC is as important as the CFM rating. Each foot of duct-work, each elbow or tee reduces the static pressure. Every device that separates the dust from the air, be that a cyclone, a thien separator, a drop out box, or a filter reduces the static available at your pickup point. If the static is all used up then no air moves, therefore no dust will move.

Most of the small portable DC have very low Static ratings. They work great for chip pickup when used as they were designed, connected directly to the equipment with a short flexible hose. When you start adding separators and duct work to these small DC's you get less than desired performance.

Most DC supplier will publish there DC's static pressure rating as well as there CFM rating. Here is a link to a spreadsheet that will help you see if the DC you select will have the power to move the desired air flow through your duct design. www.billpentz.com/woodworking/cyclone/staticcalc.xls.

I have installed dozens of Dust Collections systems. I always start with a duct layout drawing. Sizing the duct for the air flow needs of the pickup points. Then I calculate the duct losses, next I select a DC with the filtering, and/or separation needed for the application. Then most important I make sure that both the CFM rating and the Static pressure rating of the DC will handle my duct work, separation, and my pick up hood design. If any of these points are missed the DC will not perform as desired.

Most wood working tools have very poorly designed pickup hoods. Until recently this has been an after thought of the tool manufactures. This is what creates the need for very large air flows. And usually even with very high air flows you can't achieve good fine dust pick up, but you can get good chip pickup.


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## nerdbot (Sep 3, 2014)

Crank50 - I think in this thread I've been incorrectly treating "cyclone" and "separator" as the same in my head. Now that I've seen some of the Thien baffle mods for the HF DC, I will most likely go that route - mainly to pull out the big chunks before it gets through.

JeffP, for me personally, I'm not sure I can really justify the cost or space for more than 1 dust collector. The way my setup is now is that all my tools are on mobile cabinets and when I'm not in the middle of a project, they're all packed in tightly in that top right portion of the red dotted area so that I can park my car inside the garage. All my work tables (except one) are collapsible so that I can also tuck those away in between projects. My wife insists on parking her car inside the garage at night, so if I do have to setup in "her" area, it needs to be able to move over to my side at the end of the day.

This is all to say that my garage shop needs to be very mobile, and with the limited space I have to work with, pulling my shop vac cart around takes up valuable floor space. My thought was if I had a stationary central dust collector over by a wall, I'd reclaim the floor space in my main working area and I also wouldn't have to deal as much with hoses and power cables from the shop vac being pulled around all over the place. Actually, part of the problem/nuisance is that when I'm cutting or planning thick stock (I work with 8/4 fairly often), if the iVac switch isn't plugged into 2 separate circuits, I'll trip the breaker on the iVac switch. So, dragging around my shop vac also means dragging around two power cables plugged into different outlets in my garage.

So I really don't have room for more than 1 dust collector, unless I want to permanently park my car outside (another argument I lose with my wife lol). Though, I think I could swing a stationary dust collector and a smaller mobile shop vac for sanding.

Now after reading the latest responses, I'm thinking for my size shop (which I'm thinking is rather small), maybe I should just work out a better mobile cart system because it sounds like to do it right would require either a really large DC or multiple small DCs - the former being unfeasible from a cost perspective and the latter unfeasible from a floor space perspective.

Maybe I can use this thread to lay the groundwork for getting the wife to sign off on a house extension…


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## nerdbot (Sep 3, 2014)

English, thanks for the link to the spreadsheet, it has a lot of great information in there. If I do decide to go the route of a small duct system, I'll definitely make use of it.


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## crank49 (Apr 7, 2010)

> Most of the small portable DC have very low Static ratings. They work great for chip pickup when used as they were designed, connected directly to the equipment with a short flexible hose. When you start adding separators and duct work to these small DC s you get less than desired performance.
> 
> - English


Exactly the point I have tried to make on at least a half dozen posts.
Never gets any traction though.
Seems that for some reason folks think if a pre-separator (cyclone or Thein, or what ever) will keep some of the dust out of the final filter then it is improving the filtration.
It Is Not.
It is just reducing the volume of air being filtered and moving the collection point from one place to another.

For me, moving the collection point is the only benefit of adding a stage to a standard dust collector.
An expansion chamber next to a big chip producer like a planer can save the hassle of trying to suck all those chips 8 feet up and 20 feet across the room to fill up the collector bag. And, a simple expansion chamber will usually only cost you about an inch or two of static. Much less than a cyclone or a Thein baffle.


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