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Dust Collection Design - Exterior Venting

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Forum topic by jta posted 04-29-2019 05:06 AM 1492 views 0 times favorited 21 replies Add to Favorites Watch
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jta

57 posts in 691 days


04-29-2019 05:06 AM

Topic tags/keywords: dust collection

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?


21 replies so far

View Bob5103's profile

Bob5103

160 posts in 1639 days


#1 posted 04-29-2019 07:34 AM

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.

View Fred Hargis's profile

Fred Hargis

6315 posts in 3299 days


#2 posted 04-29-2019 10:28 AM

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.

-- Our village hasn't lost it's idiot, he was elected to congress.

View sammyboy's profile

sammyboy

6 posts in 480 days


#3 posted 04-29-2019 02:08 PM

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

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jta

57 posts in 691 days


#4 posted 04-29-2019 02:25 PM


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.

View Delete's profile

Delete

439 posts in 1178 days


#5 posted 04-29-2019 02:46 PM

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.

View fivecodys's profile

fivecodys

1640 posts in 2442 days


#6 posted 04-29-2019 05:02 PM

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

-- A bad day woodworking is still better than a good day working.

View Robert's profile

Robert

3792 posts in 2286 days


#7 posted 04-29-2019 06:04 PM

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

-- Everything is a prototype thats why its one of a kind!!

View Gene Howe's profile

Gene Howe

12217 posts in 4234 days


#8 posted 04-29-2019 06:58 PM

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.

-- Gene 'The true soldier fights not because he hates what is in front of him, but because he loves what is behind him.' G. K. Chesterton

View fivecodys's profile

fivecodys

1640 posts in 2442 days


#9 posted 04-29-2019 08:13 PM

(Delete)

-- A bad day woodworking is still better than a good day working.

View jta's profile

jta

57 posts in 691 days


#10 posted 07-27-2019 04:39 PM

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.

View ibewjon's profile

ibewjon

1768 posts in 3599 days


#11 posted 07-27-2019 05:22 PM

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.

View farmfromkansas's profile

farmfromkansas

210 posts in 420 days


#12 posted 07-28-2019 04:59 PM

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.

View jta's profile

jta

57 posts in 691 days


#13 posted 07-29-2019 12:01 AM

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.

View CaptainKlutz's profile

CaptainKlutz

3352 posts in 2300 days


#14 posted 07-29-2019 12:12 AM

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!

-- If it wasn't for bad luck, I wouldn't have no luck at all, - Albert King - Born Under a Bad Sign released 1967

View jta's profile

jta

57 posts in 691 days


#15 posted 07-29-2019 12:30 AM

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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