Dust collection question

[Aaron Gatzke]

I am upgrading my dust collection piping to 6”. Since it is just me, only one machine at a time will be running. From the 6” branch line, I will be putting drops to various machines, terminating in a 4” flexible hose. The question is, do I continue the 6” down to the 4” flexible hose or do I reduce down to 4” at the top of the drop, right off the 6” branch? I would first use 4“ piping on the drop until the 4” flexible hose. Or should I first reduce to 5” at the start of the drop terminating with the 4” flexible hose?
Thank you.

[Frank Pratt]

My main runs are all 8" & leg runs down the wall to 2 4" outlets. If only one of them is open, the spoil will gradually build up in the bottom of the drop. Opening both results in a bit of racket while the drop clears. I should have dropped 2 separate 4" or 1 6" for the vertical part of the run.

[Jim Becker]

In the past, I would have supported making the drops 4" off the main. I've changed my opinion on that over time. Assuming your actual DC can handle a 6" network, I'd keep the drops large because that gives you more options over time...4" now, 5" and 6" later, a split to 4" and 3" for a table saw with an overarm collection, 120mm ports which are close to 5" on most Euro type equipment, etc. Most of my drops currently are 5" with one 6" and a few 4"...but it's an old "stepped" design that's not necessary for a one person shop where generally only one tool is being used at a time.

[stevo wis]

Aaron,
I also have a 6" trunk. I would recommend leaving the drops as large as you can. I had some 4" on planer, table saw and a few other things and it is just too small. Especially the planer worked much better with larger pipes. Also keep the flexible to a minimum.
Stevo

[Aaron Gatzke]

Steve, may I ask what type of setup you have? HP of dust collector? Cyclone? Feet of piping?

[Aaron Gatzke]

Jim, you are pretty knowledgeable. Just in your opinion, I won’t hold you to anything, what is the minimum HP that could utilize 6” piping, with the Oneida SDD XL ? I have seen the video from Gray House Studio where he upgraded a HB dc with the SDD XL. I bought my 2 hp dc 32 years ago with a 12.75” impeller.
I have been researching a lot but it takes time for all that information to coalesce into useful information...

[Aaron Gatzke]

What dc system do you have Stevo?

[Aaron Gatzke]

Thank you for your reply Eric. I shall add that information into my design.

[Aaron Gatzke]

Thank you Frank.

[Jim Becker]

Jim, you are pretty knowledgeable. Just in your opinion, I won’t hold you to anything, what is the minimum HP that could utilize 6” piping, with the Oneida SDD XL ? I have seen the video from Gray House Studio where he upgraded a HB dc with the SDD XL. I bought my 2 hp dc 32 years ago with a 12.75” impeller.
I have been researching a lot but it takes time for all that information to coalesce into useful information...

This is a difficult question to answer because the kinds of DC blowers you generally would use with something like the SDD XL don't generally have fan curves available and any CFM figures you see in the marketing material are just that...marketing numbers that often represent air flow right at the point the system bursts into flames because of not having any static pressure from the lack of ducting. Bigger is better, however, so the larger diameter fan and the larger the motor, the better the performance will be "in general".

[Aaron Gatzke]

Thank you Jim. I may have to invest in a manometer...

[Bill Dufour]

or make one. Even easier if you have a water level already.
Bill D

[Aaron Gatzke]

Darn, I gave away my water level 15 years ago when I bought a small cross hair laser level...