4" DC ducting

[Anthony Whitesell]

I know I should really be looking into something other than 4" ducting, but my DC only has a 4" inlet and I haven't the money or the time to change it out.

I need to modify and expand my current plumbing. With all that I have read on DC plumbing got me to think about which DC hose would be best. In other words, which one has the least loss associated with it)?

Woodcraft carries three hoses.

Clear Heavy Duty Hose
http://www.woodcraft.com/family.aspx?familyid=20173&ProductID=147880

Clear Dust Collection Hose
http://www.woodcraft.com/family.aspx?familyid=1780&ProductID=127760[/URL]

Black DC Hose
http://www.woodcraft.com/family.aspx?familyid=899&ProductID=03H71 (http://www.woodcraft.com/family.aspx?FamilyID=1780)

Peachtree has a fourth

Black Wire Reinforced Sluper Flex

[URL]http://www.ptreeusa.com/search_results.htm?cx=007399465361678823823%3Aq2ut khbmmhs&cof=FORID%3A11&q=378#146
or
http://www.ptreeusa.com/dusthose.htm

[alex grams]

Rockler has the equivalent clear plastic hose on sale for 19$ as opposed to the 39$ from Woodcraft.

And all things considered, you probably won''t find much difference in performance of 1 4" hose vs the next 4" hose. The main performance you would gain would be from PVC piping or a 6" hose/pipe.

[Matt Benton]

If I understand things correctly, your ability to capture dust is related to the volume of the entire system, not necessarily by its smallest diameter. If this is the case, I think you would benefit by going to 6" pipe.

Maybe someone else can verify this...

[Anthony Whitesell]

System volume is relative. Long narrow ducting will not be as effecient as a short wide duct of the same volume. The ability to capture dust is dependent on the effeciency of the DC system itself and the airflow it can provide. The airflow is mostly dependent on the motor, impeller, and length, diameter, and smoothness of the ducting. To put it more simply, the ducting has to match the performance of the collector. I know I'm outside those parameters and pushing the performance of the collector already. I'm trying to make the best of what I have. I wish I knew six years ago what I know now, it would have saved me lots of $$$.

Since I can't change the motor, impeller, or duct diameter; I'm stuck with length and smoothness. Right now questioning which hose has the least loss. (trying to get the best of a bad thing)

[Matt Benton]

So are you saying that, if everything else is equal (run lengths, motor, impeller, etc.), I won't get higher cfm's from 6" pvc than 4" pvc?

[alex grams]

The larger the pipe the better your flow will be. It has nothing to do with the volume of the system, but all with the cross sectional area of the flow in your system.

It is all based on the velocity of the flow within the pipe. The higher the velocity the more friction in the pipe, the more energy loss and the less the flow.

The smaller the pipe, the worse
The longer the pipe, the worse

I would just say make the reasonably shortest run with the reasonably largest pipe you can (being 4" in your case). The differences in types of hosing from one 4" style to another won't really be a huge factor compared to if you ran a 2.5" or added an extra 30' of hose to your run.

Are you running branches, or a single hose connected to a machine at a time.

[Anthony Whitesell]

I now know I should not have 4" ducting (but it's so available:confused:), but it's too late.

I have two branches. The main run is up the wall (~6') and over the storage closet (~4'). The main wye's at that point. One side immediately drops to the router table area and the other side runs ~10' to the table saw area. I need to relocate the wye to the top of the wall and re-duct the run to the T/S area to allow for a new drop to be placed for the 17" bandsaw.

If there isn't that much difference, then I'll stick with the black plastic non-wire hose. It is the easiest to work with.

[Gary McKown]

No expert but one who has several of the items noted, and I'm gonna differ a bit from the previous replies. First, I think there is a difference between the various types of flex in terms of resistance to flow. I have some of the Woodcraft stuff (first link), which is somewhat more smooth and heavier construction than that of the second link (which I think is the one equivalent to the Rockler flex on sale). I have some of the Rockler too, which I would place between the Woodcraft and any of the black plastic offerings. I have Penn State's wire-reinforced black plastic (came free with the DC), which I think is far less effective than the clear but better than the corrugated black plastic pipes you referenced. (The wired plastic works O.K for short runs that stay extended fully, less so if there are still crinkles in use). IMO, the ones made like cheap shopvac hose may be O.K. for high suction, low flow uses but not so good for low suction, high flow.

If buying for the first time, I would go with the mid-grade Woodcraft (or the Rockler on sale) as the cost effective option.