Dust Collector Specifying Assistance

JackLeg · 04-05-2008, 05:15 PM

OK, I'm back seeking your assistance and input again on the same topic!

My DC "trunk" line run will probably be in the neighborhood of 30' from the DC to the fartherest point, not counting the drop length. My ceiling is 10'. (Yeah, I'm running overhead>)

Sooo----, what cfm would you consider as a minimum for this length of run? I'm gonna run 4" pipe, using metal blast gates. I presently have a Delta 1 hp that I don't think is going to cut it for multiple tool use.

I'm looking at Jet, PM, HF, etc. I only want to do this once, BUT, my budget won't stand the big Cyclone units at this time.

The system will be serving: Belt sander, band saw, router table, table saw (when Alan gets his "groove going!), jointer, and that dang Sliding Compund Miter Saw that I love so well!

JackLeg · 04-05-2008, 05:19 PM

OK, I'm back seeking your assistance and input again on the same topic!

My DC "trunk" line run will probably be in the neighborhood of 30' from the DC to the fartherest point, not counting the drop length. My ceiling is 10'. (Yeah, I'm running overhead>)

Sooo----, what cfm would you consider as a minimum for this length of run? I'm gonna run 4" pipe, using metal blast gates. I presently have a Delta 1 hp that I don't think is going to cut it for multiple tool use.

I'm looking at Jet, PM, HF, etc. I only want to do this once, BUT, my budget won't stand the big Cyclone units at this time.

The system will be serving: Belt sander, band saw, planer,router table, table saw (when Alan gets his "groove going!), jointer, and that dang Sliding Compund Miter Saw that I love so well!

I've got the piping layout pretty well figured out and I figure there'll always be some clean-up to do. Just want to handle the big dust and chip makers.

Thanks guys. You can already "read between the lines" that I'm looking for a bigger unit. SO, just how big will it need to be?

JimmyC · 04-05-2008, 05:47 PM

Reggie,

Any 2hp or larger DC (other than HF, because their 2 is actually 1 1/2 hp) should do it. The lowest cfm is 1500 on these machines and that should be fine. Make sure that you have a filter (not a bag) and a seperator. I know that you are determined to run 4", but I would run 6" for the main trunk minimum and come off of it with 4" trunks. But that is me.

Back in NJ I ran a 1hp Jet(DC-650) with bags and a 4" pipe of about 25' in length, with no separator and ikt still collected most of the dust I made. So no matter what you do, it'll work up to some point. But the more you do, the better off you'll be.

Jimmy

GeorgeL · 04-05-2008, 05:57 PM

Reggie,

I agree with Jimmy, go with a 6" main. You are already starting out with a smaller DC, typically with a 6" inlet. Reducing that to 4" will only serve to decrease efficiency. Also, take a close look the DCs your are considering. Even though they may have a 6" inlet, the outlet of the blower to the filter may only be 5" (or less!) I have a Penn State DC2000 2 HP which is set up like that. I am in the process of increasing the pipe from the blower to the filter with 6" to increase efficiency.

George

Bas · 04-05-2008, 07:03 PM

Hi Reggie,

For that kind of duct work, I think you need a 2HP unit. I have the Harbor Freight "2HP" machine (which really is 1.5), and my longest run is ~25ft. That includes drops. It works well, but I'm definitely at capacity. I wouldn't bother with any of the other 110V units (HF, JET), they're not going to give you more than a 1/3 increase over your current Delta. 2HP does imply 220V though. Grizzly makes a decent machine, 2HP with canister filter. That's the one I'd get.

As far as duct work, I have 4" pipe all the way, but that's because I'm concerned about velocity dropping too much with 6" pipe. 5" pipe would have been ideal, but you can't get PVC in that size, and I wasn't crazy about going metal. With a 2HP unit, you should consider using a 6" pipe like the others suggested. Of course, 4" is cheap and can be purchased at every home improvement store. 6" is expensive and hard to find. It stinks. But, if you're going to do this, it's better to do it once.

You already have blast gates. Don't forget a trash can separator, air cleaner, remote, shop vac....it never ends.

Alan in Little Washington · 04-05-2008, 07:23 PM

First go with 6" duct, if not for now, for when you upgrade, which you will likely do, and also run 6" all the way to each machine. Where possible enlarge the machine dust port. Save money, and make your own blast gates.

As far as the blower- hp is not the only issue you need to consider- I would look for a 2.5 - 5 hp blower WITH, and this is important- a 13" or larger impeller. This recommendation will give you good CFM and velocity now and allow you to add a cyclone someday, where the smaller units will not. Pay now or pay later. If you can bend metal and solder, you can make a Pentz design cyclone for under $50 someday!

Jim Murphy · 04-05-2008, 07:28 PM

Originally Posted by JackLeg

I'm looking at Jet, PM, HF, etc. I only want to do this once, BUT, my budget won't stand the big Cyclone units at this time.

Did you hear enough folks say to go with 6" pipe? Do I need to add my 2 cents worth?

MTCW:

I think I would recommend that you go with 6" pipe.

McRabbet · 04-05-2008, 10:23 PM

Reggie -- I must join with the others in recommending 6" mains for the distances you are describing. The biggest deterrent to adequate flow in dust collection ducts is friction (static pressure loss) due to the constraints created by the walls of the pipe and the various fittings to airflow. 6" pipe has 2.25 times more cross-sectional area than 4" pipe. With 4" pipe, the static pressure losses over the distance you are contemplating will reduce the airflow over that distance to the point where it will not operate effectively. A good mental image comparison is drinking a milkshake through a jumbo straw versus a hollow coffee stirrer -- you don't even try the latter! That's how 4" pipe will perform over this distance.

Even with 6" duct, you will lose 25-40% of the airflow velocity at your farthest connection with a minimum of 44' of run (6' up to ceiling from DC + 30' to downturn + 8' to tool) -- losses at each fitting, joint and in flexible duct hookups add to that length and associated static pressure burden. With 4" duct, a stronger DC with higher airflow would be required (more $$) versus an 1,200 cfm DC at 2HP pulling air through 6 inch duct. You may need 600 cfm at a machine port to pull the dust, maybe even 800. You'll never get that with any more than direct connections (< 6') from a small dust collector.

Alan in Little Washington · 04-05-2008, 11:08 PM

Rob- I love the milkshake-straw analogy!!!

JackLeg · 04-05-2008, 11:29 PM

OK, OK! Now, where do I find 6" plastic?

Alan in Little Washington · 04-06-2008, 01:16 PM

Remember, you want PVC S&D (sewer and drain) ASTM 2729, NOT Sched 40!!! Unfortunately the pipe is not generally available in 6". Lowes, and I believe HD, only carry 4" S&D pipe, but they carry 4" and 6" S&D fittings.

There are a couple of threads here on sources of ASTM 2729 S&D (one bing my bad experience at JD). Some landscapers and irrigation supply places carry it. One source is John Deere Landscapes. There is one in Greenville that has a bunch of 6" S&D. JD Landscapes has locations all over the place now (a couple in Charlotte), just Google it. Caution, if you go to JD, go as a "contractor"- since they rip you off and you will pay three times as much if you are "Joe homeowner"

jtodd71 · 04-06-2008, 01:43 PM

Check lowes they do carry it here. Its in the back but they do have it just ask, they might have it

JackLeg · 04-06-2008, 03:43 PM

Thanks for all the input. I'm gonna check with Lowe's tomorrow to see if they have 6". If not, there's a plumbing supply house in Albemarle I can try. If those two fail, I'm gonna go ahead and put in the 4" and shorten my runs. Wish me luck!

McRabbet · 04-06-2008, 07:27 PM

There are loads of Piping suppliers in Charlotte and I'm sure one of our members has found some there -- Albemarle is probably too small a town unless their is a farm irrigation supplier there. It would be worth the trip to get 6" -- be sure you get the white bell end style versus the more expensive SDR-35 (lite green) pipe (but it would work and will fit inside the S&D fittings at Lowes, since the D2729 and SDR-35 outside pipe diameters are the same (the green pipe may also be marked D-3034, but it is harder to find the non-gasketed bell end version).

JackLeg · 04-08-2008, 10:10 PM

JUST A QUICK UPDATE ON THE INSTALLATION OF MY DC SYSTEM.

FRIEND OF MINE CAME DOWN FROM MT. AIRY (MAYBERRY!) AND WITH ALL HIS EXPERIENCE AND KNOWLEDGE, WE PUT HER IN!

WE REARRANGED MY TOOLS AND THE TOTAL TRUNK LINE RUN IS 17'!! Strapped to the wall! No pics for now, cause the shop is a MESS! (I wouldn't even let Ivey in there right now!)

So--- we put in 4" piping and the last blast gate on the line will suck your hat off your head if you get too close!

If I sound "tickled" I am!!

Thanks for all your input.

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