# Dust Collection Design - Exterior Venting



## jta (Sep 18, 2018)

So after spending a considerable time reading and humming and harring about best practice etc. I came to the conclusion that given 1. I'm working in a garage attached to the house and 2. I'm an asthmatic with at least some allergy issues (primarily pollen) - that I was just better off venting the finer dust outside as the smaller particulate issues with dust collection information I've read seems concerning (my lungs already have enough trouble). That of course leads me to the idea of a moving to cyclone to remove larger particles, which of course is somewhat prohibitively expensive at least as they are available on the scale we are talking. So how to get around it. Well here is my idea, and feel free to shoot me down:

Take a 2HP blower similar to this one to provide the air movement:
https://www.pennstateind.com/store/DC250SEMB.html
Alternatively, find one more reasonably on CL and pilfer it from its original collection system.

Take a Grizzly Growler Cyclone
https://www.grizzly.com/products/Grizzly-Grizzly-Growler-Cyclone-Separator/G0863

Given I have easy access to a window, this seems the simplest solution at least as an interim measure - using a 4" or 6" adjustable vent to the outside.

The 2HP blower seems appropriate (though it seems hard to find blowers of this size without attached DC) given I have a maximum CFM requirement of 440 (so 350 on a 4"), and would be running no more than 15 feet on any run to a single tool (mostly less), using blast gates to offset potential for static pressure drop. Main tools of relevance to this DC system are going to be the 17" bandsaw, 8" jointer and the 13" Dewalt Planer (no TS). Anyone have any better suggestions on how I could approach this more economically or effectively?


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## Bob5103 (Feb 13, 2016)

I modified my HF unit to a 12 in impeller, a Super Dust Deputy, and exhaust outside. My duct size is 5" reduced to 4" at the machines. And I exhaust outside. If the unit ever gives up the ghost I will replace it with the Penn State unit you linked to. As it is, I get decent collection at all of my tools, with the longest run being 41'. Very little dust is exhausted, it reduced the interior noise, and reduced the foot print of the machine. Depending on how long you run it will affect the heating/cooling in the shop, but for me it is worth it. If you have close neighbors you may want to do something outside to reduce the noise. My closest neighbor is 1/4 mile away and I don't have to worry about the noise. If you can do this, I highly recommend exhausting outside.


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## wapakfred (Jul 29, 2011)

I think your plan is good, the one thing I was wondering was about your allergy to pollen. Won't the outside venting raw in air with the pollen particles? I'm a big fan of venting out when possible, but in your case was curious about the impact.


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## sammyboy (Apr 17, 2019)

I had a similar plan venting outside, but our HOA's rules are very restrictive…


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## jta (Sep 18, 2018)

> I modified my HF unit to a 12 in impeller, a Super Dust Deputy, and exhaust outside. My duct size is 5" reduced to 4" at the machines. And I exhaust outside. If the unit ever gives up the ghost I will replace it with the Penn State unit you linked to. As it is, I get decent collection at all of my tools, with the longest run being 41 . Very little dust is exhausted, it reduced the interior noise, and reduced the foot print of the machine. Depending on how long you run it will affect the heating/cooling in the shop, but for me it is worth it. If you have close neighbors you may want to do something outside to reduce the noise. My closest neighbor is 1/4 mile away and I don t have to worry about the noise. If you can do this, I highly recommend exhausting outside.
> 
> - Bob5103


Nice system you've got there Bob! While the window faces the neighbors, we're on a decent sized lot and it shouldn't be an issue (quite honestly for the noise he makes I don't really care). No HOA so don't have to worry about that problem. While I'm in MI (so cold is an issue) the reduction of dust is more important than comfort.

Looking into alternatives (as I've seen varying opinions of the grizzly) - that the super dust deputy pops up. Seems like a decent option, though I do wonder about the endurance of the plastic and whether the steel one is a better choice (I have their shopvac sized unit as well).
https://www.oneida-air.com/super-dust-deputy-5-inch-cyclone-separator

Fred - in terms of allergies - Pollen is mostly a problem in that early spring window, and in the fall when Ragweed is out - so while its not perfectly desirable to be bringing in that sort of air, its better than the dangers of fine grain dust at least as I see it.


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## Delete (May 19, 2017)

If blowing dust outside is a problem there is no reason you can't get a couple of bags and the mounting assembly to mount outside, It would collect the fine stuff, reduce noise and be low maintenance if your cyclone works well.

For air movement, you have probably already thought of a negative pressure damper, as opposed to an open window or other means of supplying air. The damper opens under negative press. and closes when press. returns to normal. They don't usually seal air tight so what I did in my old shop was install a plywood cover that operated in dadoed slides to seal the damper off when not in use. It will save you on your heating bill.


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## fivecodys (Dec 2, 2013)

I run mine through a SDD and then outside through a dryer vent. Don't see any dust on the vent or the bushes in the flowerbed so I think the SDD is doing it's job well. My shop is very well ventilated so no issues with supply air.

https://www.lumberjocks.com/topics/303743


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## rwe2156 (May 7, 2014)

I also use a SDD and see little to no dust accumulating below the outlet.


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## Gene01 (Jan 5, 2009)

I just use a 35 gal. Trash can with a plastic cyclone lid as a collector for chunks and sawdust. From there, it's vented directly out side. There's very little dust accumulation out side. 
I don't detect any appreciable heat loss but, the DC only runs for less than an hour per day.


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## fivecodys (Dec 2, 2013)

(Delete)


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## jta (Sep 18, 2018)

So with the electrician coming this week to finally address my power situation (3 months to get one is rough), a question that has been coming into my mind is 2HP for DC enough, or should I be looking into a 3HP unit? There is one on CL that is at a reasonable price point, the only downside is that the provided blower outlet is of course bifurcated, so I'd have to have an appropriate single to vent outside? Just wondering if overrunning like this would be a problem, or would be preferable with a SDD. Im pretty sure 3HP would cover my needs for any tool going forward given the shortish runs.


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## ibewjon (Oct 2, 2010)

Just remember that you could be pulling CO from the furnace, water heater, or dryer into the house as make up air to replace what is vented outside. Be sure to have CO detectors in the house and shop.


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## farmfromkansas (Jun 16, 2019)

3hp is much preferable to 2hp. I moved up to 3hp, and it saves money to only do DC one time. Venting outside seems to about double your suction. I use a cyclone and a 55 gallon drum, can fill the drum in about 15 minutes surfacing lumber. The dust on the outside of my shop is from running the drum over.


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## jta (Sep 18, 2018)

Ok - So I've picked up a 3HP G1030Z dust collector for $300 off craigslist (its barely done any work for specs see https://cdn0.grizzly.com/specsheets/g1030_ds.pdf). I also ended up with a bunch of the HVAC and flexible pipe that it was attached to (though most of this was 4" and plastic). It has a 6" intake so based on this I'm thinking either a 5" or 6" main run with 45 angle offshoots with closable blast gates - the main run won't be very long (15 feet). If input to the blower is 6" that means I'll either have to run an SDD XL or run a reducer to hook up a SDD 5" model.

Anyone have any thoughts or suggestions on this in terms of CFM performance of doing this and which would be preferable?

Given most of my tools have 4" outs - I'll have to run reducers, and for convenience will probably run flex hose for the last part of the run.


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## CaptainKlutz (Apr 23, 2014)

Dust collector = Good idea. 
Get biggest system (3-5HP) you have room to install!

A cyclone system is nothing more than a 2 stage system to reduce load on the filter elements. If you can keep the air from returning to shop or entering into the house with an external vent; you can just vent the blower outside and collect your saw dust in giant pile out side with shovel. 

Since you mention asthma reactions to airborne pollen, and it appears you don't already know your sensitivity level to wood dust; must share a warning:

Anyone who has asthma reactions to airborne tree pollen can expect occasional serious issues working wood. I am not talking about inhaling wood dust, we all know that is bad. I am talking about allergic reaction to small amounts of dust or contact sensitivity just touching it.

IME - If a person has any allergies to tree pollen (big or small), you can expect to have serious issues working certain woods. Each person's sensitivity and reaction is slightly different, so even if some reference table says 'mild' reaction, a person with tree allergies might have very severe reaction. 
References:
https://www.wood-database.com/wood-articles/wood-allergies-and-toxicity/
https://www.wooduchoose.com/BlogPost/?Toxic-Wood
http://www.carbideprocessors.com/pages/woodworking/wood-allergens.html

If you don't want to believe someone who has dealt with tree allergies for 40+ years, which during about 20 of those years was taking weekly shots to reduce severity of reactions; look it up or ask your doctor for more allergy tests. 
My entire family has issues with one wood or another. Our doctor(s) has told me several times to find a hobby that does not create wood dust. Blah, I still do it with caution outside, using proper protective equipment, and epi-pen close by.

I'm lucky, my primary reaction is nasal, and an asthma reaction happens only to conifer's, or softwood. 
Which translates into when I work soft woods, I have to wear not only a respirator mask, but also an extra layer of clothes that are cleaned off outside before removal, and never allowed anywhere in the house. The shop is also blown clean to the outside with compressed air when done for day.

Softwood is not my only problem; Red Oak absolutely drives my nose insane, and small amount of fine sanding dust that escapes the vacuum, makes my skin break out in hives. Oily woods like; bubinga, cocobolo, rosewood, Pau Ferro, chechem, or cedar, are all down right dangerous for me to sand without protective gear.

Yes, I have 1.5HP dust collector swapped to every tool during use, and shop vac for sanders/routers. Shop doors are always open when working, shop is never really dusty. Plus my 24/7 running fine dust air filter will go 3+ months between filter changes. I even put a box fan with filter pulling air away from me when I sand (really need a down draft table, but no room).

Allergy (mast cell) reactions can be slow or fast, and are dependent on bodies starting state. But if you want to know if certain wood will create issues, lightly sand a piece of wood with 150 grit, knock most of dust off, take a good whiff of the board, and rub it on your arm for a few seconds. Wait an hour, and document how you feel. If you typically can have a strong asthma reaction, keep the epi-pen close. Trust me, you will surprised by results of this test. 
Several places sell wood sampler kits, though not intended for allergy testing, they work just fine.
https://www.woodworkerssource.com/woodworkers-30-piece-sample-kit.html

Anyone with allergies to tree pollen should plan for worst with biggest baddest dust collector, down draft sanding table, and shop vacuum on small tools; trying to get reach theoretical 100% collection; yet still have hope for best.

as always, YMMV.

Don't be a Klutz and find out the hard way!


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## jta (Sep 18, 2018)

Thanks Klutz - appreciate the suggestions and additional reading material, will definitely be running tests on the wood dust to see how I react. I keep an epi-pen handy for bees (family history of issues) and always have the reliever with me in case of Asthma. My doctor also kind of had a 'can't you find another hobby' look on his face, but I figure I'm paranoid enough that I can keep myself reasonably covered and out of trouble. If skin contact with a wood is too much of a problem I think I'll just selectively avoid working with it. My wife is an immunology researcher, so you can bet she will be telling me off if she sees any sort of reaction.

In terms of the system, seems like this 3HP should be the go. The main reason I want to run a cyclone is just reduce the outside dust/chips to a bare minimum (wife would get annoyed at too much sawdust in nearby garden beds), and then vent the finer stuff.

Definitely planning on building a downdraft table in addition to the shop vac (bag collection) for use when sanding, as I reckon thats going to be the riskiest part. On the positive side, it seems that I don't have a reaction to either Teak or Cherry (which I've worked with for a few things).

I do need to look into an air filter as well. Anyone have any suggestions?


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## jta (Sep 18, 2018)

So have been going further down this plan, after looking at my tool orientation - Going to go with a SDD XL for the 6" port. This will be coupled to the 3HP Grizzly blower in a stand I build on top, with the blower running a 6" out in flex to a dryer vent in the window (until I work up the nerve to drill the wall). Below the SDD I'll have a short section of flex and a steel drum, with an easy way to remove/roll out. The SDD will be attached to a main run of 8-9 feet to a double 45 degree elbow (to get a long 90), to an 11 foot run along the back wall. Along this main run I plan to run 3-4 Ys with blast gates (probably 4, or 3 with one coming off the end of pipe with blast gate). From each of these I plan to have a short drop run of 6" reinforced flex, which will then step down to tool outlet size with a fitting - the last will be longer for floating tools. As most of my tools are 4" outs, this will probably be my standard step.


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## wapakfred (Jul 29, 2011)

Try to upsize any tool ports possible to 6", on some this is a piece of cake, others take some engineering, and on some it just can't be done.


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## farmfromkansas (Jun 16, 2019)

My planer is a Grizzly G0453px, which has a 4" port, and it is the easiest piece of equipment to collect from, so just left it alone. The sanders are the hardest, and I enlarged them to 6". My jointer is 5", I just put a 5 to 6" adapter on it. Seems the largest chips are easiest to collect, and smallest chips are hardest.


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## jta (Sep 18, 2018)

So semester turned into a semester from hell, which meant that pretty much all this work got dropped and I've been forced to makeshift/work outside. I did manage to get my electrical supply sorted out, so I have an appropriate 220V circuit for the 3HP Grizzly blower and now have an idea of where my tools will sit. I'm tossing up between running out along the roof with drops outward or around the edge of the garage, but not sure it will matter too much for SP given the amount of suction I have across no more than 25 feet of 6" that I plan to run.

Needing an opinion on what to use for chip collection under the SDD XL - I was looking at a barrel - either the 35 gallon steel one that Oneida sells, or potentially using one of those thick food grade 55 gallon plastic barrels with a ring secured lid. Do I need go with steel, or would the plastic work out alright? The plan is to suspend the blower and SDD XL in a bracket I build onto the wall, and have a 6" flex drop to the barrel which will have an internally weighted bag and will be on wheels so I can take it outside for emptying.

Also - anyone have a recommendation of a good air filter for a ~20×20 garage?

Still working on a source for ducting - going to try a local HVAC place, but naturally at this time of year, its a bit tough to find places that are open.


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## ibewjon (Oct 2, 2010)

Wen air cleaners. Two can be purchased for the price of one jet. Home Depot delivered mine to the house free. My shop is 16×24, so about the same size.


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## Bob5103 (Feb 13, 2016)

The easiest and less expensive container is a 33 gal metal trash can. I think mine was $11.00. I sealed mine with silicone calk and epoxy. I made the top out of ply, made a "slip" ring to fit under the rim of the trash can and a top for the SSD. I used inserts and shop made bolts to hold it together. Weather stripping and a groove to fit over the rim makes it air tight. The brackets hold the lid and SSD in place, so the can drops to the floor when it needs emptying. Here are some pics that explain it better than I.


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