Ducting help

[Mark Visconti]

A couple of questions I haven't seen asked prior -

Set up is 2.5HP Oneida Gorilla. Limited number of machines today. TS, J/P combo, Router table. Other tools in the future. Single blast gate open at a time (other than the tools that use a large dust port and a small dust port).

Currently working through Nordfab quickfit configs.

Is it better to run 7" an additional 12-15' with 2 long radius 90's over 7' of 5" ultraflex ? The hard run would be all the way to the dust port. I found a reference that implied that the loss in flex hose can be 2x+. The advantage of the longer runs is that it removes issues with the ultraflex being in the way when moving around the shop. Basically, I can do a vertical drop above the machines or I can run over to the wall and down and back out. I guess a good option with QF is to do the minimal and then add as I go since reconfiguration should be relatively easy.

Another question - I'm coming out of the cyclone with a 5' straight connection and then using two long radius 30 deg elbows with a straight section to move up to the ceiling. Any comments about using a wye on the 30 degree vertical ? I'm having to work around existing HVAC ductwork and this is one of the options I'm considering. It basically wyes under the HVAC. Angles could get a little funky... The other option would be to convert the 5' straight from the cyclone into a 3' and then the wye. That may be a bit cleaner than strange angles.

Thanks,
Mark

[Mark Visconti]

Some Sketchup pics - most stuff unrelated to DC omitted. I did not show the last section that would be flex and reducers.

Proposed Duct work in white. I also show the HVAC in blue/red

The cyclone is NOT going to move. Everything else is on wheels. JP can move closer to the outside wall as well when not using the mortiser. Yes, I wish I had gone with the shorter rails and smaller extension table on the TS. I have plenty of regrets :)

A drop right between the TS and JP would sure make things simpler but I think I would beat my head on it or trip on it 10 times a day.

No blast gates shown. My straight lengths are standard at 5' increments and I didn't always model the variances (you won't see a QF seam in the model). Down drops to table saw and router table are 6" off the floor. They just require a second piece.

EDIT: Missed a wye for a 4" drop over the TS for the overhead guard/DC.

[John Keeton]

Mark, I went through a tremendous amount or fuss and research prior to doing my DC install. My unit is the 2.5 like yours.

The area served by your system appears to be about 16' square. My shop is 24 x 24. Honestly, with the unit you have, it won't matter much what you do. In the end you will end up with a system that will suck the paint off the walls.

Personally, I would not like the duct on the floor or below head high. It is just too obstructive to moving machines, material, etc. You say that most of your machines are mobile - why not run the duct overhead, with drops to just above head high, and put in quick disconnects? You can have the flex attached to your machines that are rolled out of the way most of the time.

For what it is worth, you can see my adventure at this thread
http://www.sawmillcreek.org/showthread.php?p=801479

I roll my planer and jointer to one of the drops and the suction holds the connection. The suction is so powerful I have to be careful about laying small objects on the planer bed. I can lay a handful of shavings on it and they will immediately get sucked thru the system.

I realize that I am probably not getting the maximum CFM from my system by having 4" flex, etc., but I would have a hard time telling that is that case.

I get 100% pickup from the planer, jointer, BS, router extension table, and probably 70% from the TS. I get only blade spinoff on the TS. The TS will improve once I install an overhead guard (a roundtuit!)

A maximum efficient system would not net me anything.

For those that will ultimately take me to task for making these statements, I acknowledge in a bigger environment, operating multiple machines simultaneously, more complicated duct systems, etc., then the attention to maxing out the system is warranted.

In your case, and in mine, I think the emphasis should be on a workable environment. Your system is going to suck hard - no matter what you do!

[Anthony Whitesell]

Following John's recommendations, I would not lay hard pipe at ground level. One option would be, as John mentions, to put the drops at the ceiling with QC fittings and use flex hose from the ceiling to the machine. The other option would be to run the drop down the wall (part or all the way) and then have QC fittings. The only real difference between the options is the second has less flex hose required/used.

[Ed Labadie]

John is correct!

I did the best I could with my 3hp Oneida, it may not be 100% perfect in the flow department but I get excellent performance from it.

IMO, it's pretty hard to "choke off" one of the Dust Gorilla machines to the point where it won't do what is required of it.


Ed

[Scott Wigginton]

I agree with Jon that you should go with duct runs above head and do vert drops.

Air Handling Systems (http://www.airhand.com/designing.asp) has a great Designing a System page with lots of info on dustwork CFM/travel velocity (FPM) and how to calculate SP. Using the fan curve (http://www.oneida-air.com/gorilla_25_curve.php)for your system and assuming you're gonna keep the 7" main, you need to keep your SP under 7.5" to keep the minimal travel velocity of 3500 FPM (950 CFM). As a self mental exercise (boredom) I ran a simple theoretical setup for your shop and at 3500 FPM only got a 6" SP.

2.3" SP inherent with filters
20' of 7" plus two elbows (1.3" SP)
20' of 6" plus two elbows (1.54" SP)
5' of 4" plus 5' of flex (0.825" SP)

Thats a good amount of suction in my book!

-Scott

[Mark Visconti]

Thanks. Reorganizing to get it above my head and do tool drops.

[Mark Visconti]

Any recommendations for sourcing quick disconnects ?

Oneida ?

I'd like the disconnects at about 5' or 6' off the ground with flex coming down from the hard ducts.


Mark

[John Keeton]

Mark, in the thread I referred you to I have pics of what I used. There have been some other threads on this as well. Some have used this http://woodworker.com/sitenews/fazlok.html but I can't comment as I am not familiar with that system.

On my mobile machines, I have the flex on the machines with the male end on the flex.

Hope this helps.

[Jim Becker]

Any recommendations for sourcing quick disconnects ?

While I have a lot of duct work from Oneida, I did get my (4") quick disconnects from Grizzly. It may be a matter of size availability, however, for the particular drops you need to use them with. I only have two overhead drops setup this way; one over my bench and normally used for the hose to my router table setup on the slider and one at the other end of the shop which was originally used for the drum sander I used to use, but now for incidental convenience.