Can you guys help me get started understanding DC systems?

[Tom Rick]

I am just setting up a new shop and only have a inherited 2hp single bag DC. No hose runs or gates or cyclone as of yet.

What I need when I get it all installed.
DC for 12" jointer/planer combo machine, table saw, shaper, belt/disk sander, and some sort of shop built sanding table.
The shop is a smallish free sanding frame building of 18' x 25'

What I am thinking:

Two 5" trunk lines run in the joist space in floor down each long side of building. Stubs up through floor to each machine. Gates at machines.
I am thinking that I will bring the two trunk lines together below the floor and run up inside a wall to dump into a cyclone before exhausting out building with no bags.

Questions:

1) How does the length of runs effect the efficiency of these systems? (it looks like 4' drop from each machine, a max 20' run under floor, and then a 8' lift to cyclone.

2) Is the 8' lift from under floor to top of cyclone a no no in system design?

3) I have so far a few 8' lengths of 5" pvc I am thinking of doing all the under floor runs in this stuff. Appropriate?

The base machine is this one:
http://www.leneavesupply.com/Machinery/NorthState/P04004.aspx

A 2hp 220v 1200cfm machine.
I am thinking of buying this cyclone:
http://cgi.ebay.com/Cyclone-Separator-for-Dust-Collector_W0QQitemZ270423194251QQcmdZViewItemQQptZ LH_DefaultDomain_0?hash=item3ef67a7a8b

4) Is there a good way to know that the cyclone is a good match for a given fan/motor DC?

Thanks all for any info you can provide

[Jesse Wilson]

Just recently going through what you did, the best advice as a first step would be to spend about a day on Bill's site before you do anything.

http://billpentz.com/woodworking/cyclone/index.cfm

[Sherzod Niazov]

Just recently going through what you did, the best advice as a first step would be to spend about a day on Bill's site before you do anything.

http://billpentz.com/woodworking/cyclone/index.cfm

Agree, Bill Pentz and this forum will educate you pretty well on dust collection.

[Tom Rick]

Reading reading reading.... thanks very much, that link is just the ticket!

Edit...

Ok- finished reading the site.
Leaves me with a question on how define the capacity of my unit.

Can my 2 hp unit be trusted to have a capacity of 1200 cfm?
If so I looks like I am headed to 6" hose through out for the system.

[Jim O'Dell]

Keep in mind that a cyclone or a Thein separator will reduce some of your usable CFM, and rarely do DC units produce real world figures that match the manufacturers claims. :rolleyes: Nature of the beast. I don't know what the ebay cyclone will do, but I do believe some here have purchased it. Hopefully they will chime in with some real world information on how it performs to help you with your decision. That information will help in what size pipe to use. If your set up won't real world create the CFM that a 6" pipe will permit, then it may work against you. But run the largest pipe that your DC will handle properly.
I personally like running piping overhead. I think not having the pipe go up and curve sharply to the cyclone inlet is advantageous to the separation of the finer dust. I understand the advantages of having the pipe below also. Any possibility you have space under the floor (basement?) that you could put the cyclone underneath and have the best of both worlds? My dream shop would have a basement under just for that reason. Also isolates the noise a bit from the shop. Could still be exhausted outside.
I know I've raised more questions that answers. Just some things to think about. Jim.

[Bill LaPointe]

Tom,

Am installing a system similar to yours. I plan on exhausting outside with out bags or filters also. I wonder how much noise and dust will be exhausted .

[Tom Rick]

Yes on overhead for lots of reasons but this shop is so small that I am just able to swing long boards around as it is. If I drop a bunch of DC piping I will drive myself crazy (keeping in mind that it does not take much!). I suppose that I could run the trunk lines near the wall on both sides and do drops in the walls and out at near the floor....
The shop is in a boat yard with so much glass and gravel dust flying about that I am not too worried about my bit of wood dust entering the mix by exhausting with no bags. I could just use the bags but thought I am gaining in the whole CFM battle by not having them.
A work in progress to be sure.

[Joe A Faulkner]

I was planning to vent my DC out the wall as well, until I considered that I really don't want to send heated shop air out the window. If you run AC or Heat in your shop, you probably want the return air staying in the building which means you will want filters.

[Bill LaPointe]

I was planning to vent my DC out the wall as well, until I considered that I really don't want to send heated shop air out the window. If you run AC or Heat in your shop, you probably want the return air staying in the building which means you will want filters.
While my shop is in my basement, I only heat when I'm working in cooler weather and never A/C in the warmer seasons. I open the overhead door most of the time. I am blessed with a 1600 sq ft shop but I am also blessed with 1700 sq ft of tools. I was more interested in getting the DC and noise out of the shop area.

[Paul Wunder]

Tom,

The short answer is that most portable D/C's cannot be relied upon to deliver more than half of their rated capacity and that capacity is usually delivered through a 4" pipe. This is true for even the best (such as a Delta 50-760).

Adding long ductwork and a cyclone will put a further strain on the D/C's abilities. If possible, see if you can obtain a "fan curve" chart from Leneave which should tell you how many cfm can be delivered at a given static pressure. Keep in mind that ductwork, cyclones, and other separators can seriously reduce the air flow.

Since you already have three lengths of ductwork, have you thought of hooking it up to one or more of your machines and give it a "real world" test? That approach will be simple and will let you know immediately (at low cost) what you are dealing with.

[David Giles]

I like your general approach. Plugged filter / canisters really decrease air flow, so outside venting will solve this problem. The ebay cyclone should remove the bulk of all wood solids. Consider the following suggestions:
- Upgrade all piping to 6" including the runs to each machine. Air flow is your friend. 4" ports or duct severely limits the air flow.
- Elbows and turns create lots of pressure drop which slows the air flow. Using 6" duct means the air velocity is less which means the pressure drop is less also. Smaller duct needs long sweeping elbows. 6" duct can use shorter radius elbows for the same pressure drop, a necessary trade off for tight spaces.
- It's not that hard to put a 6" port on each machine. Lot's of SMC posts on that topic.
- The 2HP blower should be fine. I run 6" line and ducts with a 1.5 Hp blower without solids buildup.
- Consider locating the blower before the cyclone. Pressurizing the cyclone keeps the bags from collapsing. A metal trash can is not necessary. Damage to the blower impeller seems more theoretical than real.

[Foras Noir]

Great book - less that $15. You can have it in two days.

Sandor is an expert and teaches the topic from start to how to do the actual calculations you need to get beyond folklore.

http://www.amazon.com/Woodshop-Dust-Control-Sandor-Nagyszalanczy/dp/1561584991/ref=sr_1_4?ie=UTF8&s=books&qid=1271699180&sr=1-4

[Greg Portland]

Read up on the Bill Pentz site, it's the best source for HOME and 1-person shop dust collection. Most other resources base their calculations and comments on larger multi-person shops.


1) How does the length of runs effect the efficiency of these systems? (it looks like 4' drop from each machine, a max 20' run under floor, and then a 8' lift to cyclone.Length is important but the smoothness of the pipe wall (hose is horrible!) and number of bends is much more of a factor. Bill's website will give you the details.[/quote]


2) Is the 8' lift from under floor to top of cyclone a no no in system design?Shouldn't be a problem with a properly designed system.


3) I have so far a few 8' lengths of 5" pvc I am thinking of doing all the under floor runs in this stuff. Appropriate?5" is too narrow for most applications, you will want 6" or larger for your main trunk line & 6" for most large tools.


4) Is there a good way to know that the cyclone is a good match for a given fan/motor DC?Yes, see Bill's website for more info.

Your jointer/planer and shaper will overwhelm that dust collector. I would strongly consider selling it and installing a machine that will handle the load. Oneida & Clearvue have popular off the shelf solutions or you can build your own cyclone (Bill's website has plans).