Basic DC Drop Question

[Steve Kang]

Hi All,

Looking for a little advice on ducting diameter. My DC is a laguna P|flux2 which should be rated for 2hp, the impeller is 14.5". I'm planning on running a 6" main line across the left wall and having 5" branch lines cross over to the planer and bandsaw. From there the they'll connect up to 4" dust ports, which I'll look at enlarging sometime in the future. I also have a table saw, but I don't plan on using it or connecting it up to the DC for another couple years.

Should I bother with dropping down to 5" branches or should I run 6" ducts everywhere I can? I'm concerned with DC's ability to pick up chips on the vertical, unless i neck down and increase the flow speed.

Thoughts?

workshop.jpg

[Ole Anderson]

5" drops should be just about right. Work well for me.

[stevo wis]

I agree with Ole. 5" ridgid as close as you can to the machine seems to work well. Have you considered going diagonal across the ceiling? It might shorten some lines and you would be pulling at 45's instead of 90.

[Steve Kang]

Thanks guys, picking up material today and should have this sorted by the end of the weekend.

@Stevo, I though about it but i'd lose headroom as it's a basement shop.

[glenn bradley]

Thanks guys, picking up material today and should have this sorted by the end of the weekend.

@Stevo, I though about it but i'd lose headroom as it's a basement shop.

Then try for long sweeps or a combination of two 45's versus the 90's; they put a terrible hit on your airflow.

45-not-90.JPG

[Jim Becker]

5" is nearly an ideal drop size for many applications...most of mine are 5". The only exception is the one that goes to my J/P which is 6" (and comes off the initial portion of the 7"-6" main trunk) but transitions to 5" flex at the gate behind the machine.

[Steve Kang]

Then try for long sweeps or a combination of two 45's versus the 90's; they put a terrible hit on your airflow.

45-not-90.JPG

Hi Glen, I know it's verboten around these parts but I'm going to use smooth bore flex hose to create the sweeps. I feel they'll be very comparable to the double 45 method.

[Jim Becker]

Since you're embracing 5" drops, you must be using metal duct work. Why use the "smooth bore" flex for the turns when you can get a smoother transition using metal long-radius elbows? Even if the flex is "smooth" in side, the nature of the material is going to provide more resistance to air movement than hard pipe will.

[Steve Kang]

Honestly, it's just because working out ducting is a headache and I'm starting to loath doing it. A few hours searching for sewer drain pipe was a waste of time, another few hours looking into 24g stove pipe was similarly wasted. I then went to rona and a home depot and neither had everything I was looking for, so I went home in frustration and ordered online. I did look into long radius elbows and they were quite expensive... So yeah, I'm going to throw it all up and see how well it sucks. If I need to do it I'll do it, until then I'm pretty sure i'll get by just fine.