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Dust Collector enough HP for ducting?

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Forum topic by LucasWoods posted 10-13-2017 12:56 AM 808 views 0 times favorited 43 replies Add to Favorites Watch
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LucasWoods

332 posts in 1173 days


10-13-2017 12:56 AM

2 questions here.

1. I own an older Grizzly 2HP dust collector with a fabric 2.5 Micron bag wired for 110. Is this enough HP to run some ducting? I only have a 2 car garage and would like to run ducting from the the edge to the center of the shop to be able to connect up to my tools easier.

2. With a dust collector with a 2.5 micron bag will I need to still wear a respirator while operating machinery?

-- Colorado Springs, CO


43 replies so far

View Grundy51's profile

Grundy51

3 posts in 126 days


#1 posted 10-13-2017 02:21 AM

You may want to check your unit’s specs and look at this website for duct sizing and CFM flow.
http://billpentz.com/woodworking/cyclone/ducting.cfm#ducting_diamter
I am in the process of setting up a Harbor Freight system (aprox. 1 1/2 HP) with a Wynn HEPA filter, Rikon 12” impeller and Oneida 5” Dust Deputy. My system will be hooked up to one machine at a time and I figure about 800 CFM output and should do a decent job of source pickup.
Currently I use a shopvac with Hepa filter and dust deputy attached to machines.
To further clean the air I built an air filter box with an attic fan and 4” hepa filter mounted to the ceiling with a timer switch of up to 4 hours run time. My workshop is 20×28 and running the unit while working and for about an hour after the air is clean as measured by my Dylos air measure instrument.
I also wear a 3M P100 mask with this setup, hopefully the new system may be enough to do away with that.
In my opinion a 2.5 micron bag will just put a lot of bad dust (small particles) in the air and the use of a good mask is required.

-- Alan, Michigan

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LucasWoods

332 posts in 1173 days


#2 posted 10-13-2017 02:27 AM

How small do you need to go?

Isn’t 2.5 micron government recommended to specifically pull the small stuff out of the air?

-- Colorado Springs, CO

View jonah's profile

jonah

1473 posts in 3138 days


#3 posted 10-13-2017 03:20 AM

No. The harmful dust is the really small stuff. 2.5 micron is probably average for felt bags. It’s not nearly fine enough to catch harmful dust.

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LucasWoods

332 posts in 1173 days


#4 posted 10-13-2017 04:33 AM

When this bag needs replacing should I get a 1 micron?

Is there smaller micron bags or canisters?

-- Colorado Springs, CO

View Loren's profile

Loren

9639 posts in 3488 days


#5 posted 10-13-2017 04:46 AM

You’ll be fine running one duct line for sure.
Try to minimize bends in the duct. You
can add branches but use blast gates. The
collector will get most of the chips but the
fine dust is another issue.

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LucasWoods

332 posts in 1173 days


#6 posted 10-13-2017 05:48 AM

Yes I was planning on running one line of 4” PVC to the ceiling then having a few branches come off with flexible hose. These would have blast gates and the DC would ever be used at one station at a time.

Is there any way or point to where I won’t need a respirator in my shop?

-- Colorado Springs, CO

View Fred Hargis's profile

Fred Hargis

4766 posts in 2333 days


#7 posted 10-13-2017 10:37 AM


Yes I was planning on running one line of 4” PVC to the ceiling then having a few branches come off with flexible hose. These would have blast gates and the DC would ever be used at one station at a time.

Is there any way or point to where I won t need a respirator in my shop?

- LucasWoods

Most likely not with the setup you describe. To capture the really fine dust you need a lot of air flow, you won’t get enough with a 4” duct. Even so, I suggest you continue on with your plan and then change as you need in the future. But as you consider the next moves remember that even a world class setup doesn’t catch everything…there are still many operations where you won’t have the DC to help catch the dust…like using a router.

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

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jonah

1473 posts in 3138 days


#8 posted 10-13-2017 01:55 PM



Is there any way or point to where I won t need a respirator in my shop?

Not with that setup. You’ll need 6-8 inch trunk lines with a really beefy impeller to suck enough air to capture really fine dust at the source. You just can’t get air through 4-5” pipes fast enough to collect at the source.

Keep in mind that not every machine produces fine dust. For example, jointers and planers largely don’t. Table saws, routers, and sanders are the main culprits that produce fine dust. Of those three, only a table saw is connected to a DC system, and most table saw dust collection is pretty inadequate because they lack above-blade collection.

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Carl10

69 posts in 296 days


#9 posted 10-13-2017 02:27 PM

Lucas,

As Fred and others have said 4” duct is less than ideal. With that small of a duct you will limit your performance to below what most equipment makers recommend as a minimum for chip collection, forget about the fine dust. I would look at 5” (yes HVAC duct) or possibly 6”. This all depends on you runs and layout. First I would find a review on your machine that provides a CFM curve, then you can start adding SP based on your setup. You don’t mention a separator but it helps keep your bags cleaner which maintains airflow longer. The downside is they eat up CFMs right off the top. I have seen SDD take 30-40% of a 1.5-2HP DC CFM (RedOak found someone who states 2-2.5” of SP). A Thien or trash can separator will take even more. Add to that your ducting and you will see what to expect. As mentioned above the Bill Pentz calculator can take all this into account.

Hope this helps. Let us know what you do.

Carl

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Manitario

2566 posts in 2723 days


#10 posted 10-13-2017 02:55 PM

...

-- Sometimes the creative process requires foul language. -- Charles Neil

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Manitario

2566 posts in 2723 days


#11 posted 10-13-2017 02:59 PM

...

-- Sometimes the creative process requires foul language. -- Charles Neil

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Manitario

2566 posts in 2723 days


#12 posted 10-13-2017 03:06 PM

Not sure what happened with my first two attempts at replying. If you’re going to run duct, I’d do 6”; your Grizzly machine is a true 2hp (not like the HF DC) and has a 12.75” impeller. Anything smaller than 6” and you’ll lose the majority of your airflow to friction (static pressure). You should be able to get away with having a short run of 6” duct, ie. less than 15’ if you have a minimal amount of bends and very short length of flex duct.

Generally, the smaller particles (less than 1 micron) are the ones that get lodged in our lungs. I’d upgrade to a 1 micron or better filter.

Will this allow you to work without a respirator? Good question. I’m an ER doctor not a respirologist but I think for the weekend woodworker who maybe spends a few hours a week in the garage, the lifetime risk of developing cancer or COPD from the dust exposure is low. However, if you already smoke or have other lung issues, you might find the cumulative dust exposure a problem in the long run. I don’t wear a respirator, but I have a 5hp DC and the air in my shop is cleaner than the air in my house…

-- Sometimes the creative process requires foul language. -- Charles Neil

View Loren's profile

Loren

9639 posts in 3488 days


#13 posted 10-13-2017 05:11 PM

One thing you can do is move your dust collector
outside, weather permitting. I have two, one
in the shop and a much bigger one outside
I use for my planer and sanders. If the shop
gets really dusty I turn on the big one, roll
down the door and stick the hose underneath.
It sucks all the dusty air out real quick.

I also have an overhead dust filter. I don’t turn
it on much but it is useful sometimes.

You might want to be selective about working
with exotics if dust bothers you a lot. Most
domestic woods are not very irritating comparatively.
It is true that people sometimes quit woodworking
because of dust allergies but for most the dust
is tolerable, especially in part-time woodworking.

I find nuisance dust masks more tolerable than
a respirator. I have a neoprene one that is
pretty comfortable.

I find Bill Pentz somewhat alarmist. He may be
correct in the science of dust collection and for
somebody who is very sensitive and loves woodworking
his approach makes sense.

I use 4” PVC duct in the shop and it is adequate for
chip collection from the table saw and band saw.
Overhead collection on the table saw is very useful
and also prevents a lot of crud from hitting you in
the body. I have a 2.5” flexible trunk line for that.
I also one connected to my panel saw which gets
plenty but due to the vertical arrangement gravity
gets the better of a lot of the dust.

Anyway, I wouldn’t get too worked up about dust
exposure when you’re just getting started.

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pintodeluxe

5468 posts in 2653 days


#14 posted 10-13-2017 05:36 PM

I’m not sure how the Grizzly compares, but I have a 2hp Tempest Cyclone and it has plenty of power for a duct system. Mains are 6”, and drops are 5” or 4”. I only have one gate open at a time, but with automated blast gates that’s pretty easy to do.

My last unit was a 1hp Jet with cloth bag. My experience with the cloth bags is this… if they are clean enough to flow well, they pass a lot of fine dust through the bag. If they are “seasoned” enough to filter the fine dust, then they won’t flow well.

Without a cyclone or some kind of separator, your bags will always be dirty.

My system uses a 1 micron pleated filter, and I am happy with that setup.

-- Willie, Washington "If You Choose Not To Decide, You Still Have Made a Choice" - Rush

View LucasWoods's profile

LucasWoods

332 posts in 1173 days


#15 posted 10-13-2017 06:52 PM

So I would like to run larger ducting if possible. But I think currently for the cost it would be cheaper to run the 4” PVC then the flexible hose from the ceiling to other pieces of equipment.

Right now the inlet port on the Grizzly is I believe 4” so wouldn’t running 6” ducting be counterintuitive?

Where can I buy a new inlet port for my Grizzly DC because I do have 5” flexible hose, 4” flex hose, and 2.5” flex hose with adapters to step down. If I could I would like to run just straight 5” tubing/hose.

-- Colorado Springs, CO

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