# Setting Duct with a Super Dust Deputy



## SteveInVa (Jan 16, 2013)

I am hoping that I can get some advice from the experts here on how to best complete the redesign of my DC system. 
In January, I bought a Super Dust Deputy to make a better two-stage collection with my Shop Fox W1685 rated at 1.5 hp, 1280 cfm, with a Wynn Environmental pleated filter. It made a remarkable improvement over the Rockler Dust Right 4" dust separator. Because my shop is in a basement, with low ceiling clearance, I find it very difficult to cart the DC from machine to machine. I decided to build a stationary structure for the DC, and after reviewing a lot of plans on the web, I designed what is pictured here. The yellow dust bin sits atop a scissor jack. When it's time to empty the bin, I just release the tension ring on the lid, lower the jack, empty the bin, put it back on the jack, elevate the jack, and reattach the lid. It works well.










But as you can see from the image, I am now stretching 20' of 4" flexible hose from machine to machine. The results are good and much better than anything I've been able to accomplish with dust collection to date, but what I would like to do is to get rid of the flex hose and put in permanent duct work, which brings me to my question.

Little did I realize that you cannot use 6" pipe with the SDD because the inlet on it is only 5". So that leaves me with two choices, 4" S&D PVC (very affordable) or 5" 26 ga. steel. I'm leaning to the latter because everything that I have read urges one to use the largest pipe your DC can handle (I presume that my ShopFox can handle that, but if I'm mistaken and should just go to 4" please advise). I have found that my local home improvement stores carry 26 gauge 5" pipe for $5.73 per 2' lengths. I'd need about 30'. The real cost is in finding 5" wyes and elbows that won't break the bank. I've also learned that I have to be careful of air flow direction and that any old HVAC wye won't do because of the location of the crimp. The cost of reverse flow wyes from places like Oneida, PSI, KenCraft, and Air Handling Systems is very expensive (enough to make me want to just use 4" PVC). But then I found these wyes and elbows from Simply Plumbing. Shipping is reasonable. They also have 5' to 4" reducers and 5" starter collars that I thought I could use to make 5" ports, at least for the table saw, jointer, and band saw.

Will those wyes work? If not, can I use these plastic ones from Woodcraft?

Thanks in advance for any help, wisdom, and advice.


----------



## pintodeluxe (Sep 12, 2010)

I would go with the 5" metal pipe. I ordered my 6" 26 gauge from home depot and the cost was comparable to 4" thin wall plastic.

I had no issues with the crimp direction. It all points the correct direction for a vacuum system.


----------



## rwe2156 (May 7, 2014)

Definitely go with 6".

Use a 6 ->5 " metal reducer. Most DC suppliers will have the adapters but you can probably use this.

A section of flex with wire removed made a perfect sleeve to fit the 6" PVC.

I bought my pipe and fittings from an industrial plumbing supply.


----------



## SteveInVa (Jan 16, 2013)

I thought of using 6", rwe2156, but Oneida says on their FAQ for the SDD that they don't recommend using 6"; in fact, they warn that "pipe diameter should never decrease in size on its way towards the dust collector," which is what using a 6>5 reducer (or increaser in this case) would do attached to the inlet of the SDD. Is that not true? Or does Oneida print that to encourage you to buy the more expensive SDD Deluxe, which has the 6" inlet?

Either way, would those wyes from Simply Plumbing work? I ask because they don't have crimps, and I don't want to order them and discover that I can't properly attach pipes to them. The cost between 6" and 5" steel for the fittings from Simply Plumbing is that not that great.

Designing a layout will be a puzzle because of the low joists and even lower hanging load-bearing beam and maze of water pipes.


----------



## JBrow (Nov 18, 2015)

SteveInVa,

By my way of thinking, running pipe larger than 5" would choke of air flow at the cyclone with its 5" port. This is in-line with what I understand to be a basic design tenant in plumbing. You can go larger on your way back toward the end of the line (the cyclone), but never smaller. This principle makes makes sense to me for dust collection. Nonetheless, following the manufacturer's instructions is probably the best way to go. I noted that the geometries of the Super Dust Deputy (5" inlet) and the Super Dust Deputy XL (6" inlet) are different. There may be some performance design considerations that prompt Oneida's caution to avoid inflating the main trunk line on the Super Dust Deputy beyond 5".

I could not find a performance curve for your dust collector. The performance curve and the greatest static pressure for the various branches of the system are needed to predict how well the dust collector could work under a particular duct work design. I did look at Oneida's 1.5 hp Mini Gorilla cyclone dust collector and see on that machine's performance curve, the static pressure needs to be kept less than 7-3/4" inches for the Oneida collector to work effectively. This static pressure for you collector may be and probably is different, but unless you can find your collector's performance curve, the Oneida performance curves is the best approximation of which I can think.

An efficient duct work layout is the best method for minimizing static pressures; short straight runs, minimal and long sweeping turns, and minimal use of flex hose. As to pipe size, by my figuring at 3500 feet per minute of air velocity, a single straight run of 30' of 5" rigid pipe will cost about 1-1/4" of static pressure while the same run of 4" pipe will cost 1-5/8" of static pressure. A long sweep 5" 90 elbow will add about ¼" to the static pressure while a 4" long sweep 90 will add a little less (.22" static pressure). A commonly used method is to install a larger trunk line (5") and then 4" branch lines off the main trunk.

Perhaps you could purchase one fitting, maybe a wye and 90 elbow to get an idea how well the fittings will install. On my former system, I married the plastic fittings (purchased from Grizzly) to metal 4" HVAC piping. If I recall correctly, the fittings' reduced diameter on the ends fit inside the metal pipe. If you marry the plastic to the metal pipes, I would personally install a short length of wire to connect the metal pipes, electrically bonding the pipes together. Then, back at the dust collector I would bond the piping to the dust collector. Electrically bonding the duct work back at the collector strikes me as a quick and prudent thing to do and would be appreciated should the duct work ever become inadvertently energized.

If at all possible, avoiding the adjustable HVAC elbows in favor of smooth walled elbows should offer a slight improvement in air flow. But if you use the adjustable elbows, ensuring all the seams are sealed would reduce or eliminate leakage at the seams. Also a pair of adjustable elbows set at 45 degrees and then connected together would offer a long sweep 90 and should improve air flow.

The Shop Fox dust collector manual has a number of tips for installing a central piping system, including what they believe to be good and bad duct work layouts. This would be a good resource to review while you are still in the planning stages if you have not already done so.


----------



## Redoak49 (Dec 15, 2012)

For those interested, the performance curve was published in Wood Magazine in March 2008. I do not have a direct link but I think it was on the Oneida Air site


----------



## AZWoody (Jan 18, 2015)

I would stick with 5", not for the reason of choking down but after going through the cyclone, you will have a loss in airflow and I doubt the dust collector would be able to maintain velocity in a 6" duct to keep the ducts clear.

Not even sure 6" would be best for that dust collector even without the cyclone.


----------



## SteveInVa (Jan 16, 2013)

Thanks, JBrow, for the taking the time to post a very thorough and informative reply. This is all material to ponder as I plan my system.


----------



## rwe2156 (May 7, 2014)

> I thought of using 6", rwe2156, but Oneida says on their FAQ for the SDD that they don t recommend using 6"; in fact, they warn that "pipe diameter should never decrease in size on its way towards the dust collector," which is what using a 6>5 reducer (or increaser in this case) would do attached to the inlet of the SDD. Is that not true? Or does Oneida print that to encourage you to buy the more expensive SDD Deluxe, which has the 6" inlet?
> 
> Either way, would those wyes from Simply Plumbing work? I ask because they don t have crimps, and I don t want to order them and discover that I can t properly attach pipes to them. The cost between 6" and 5" steel for the fittings from Simply Plumbing is that not that great.
> 
> ...


I guess all I can say is I used the reducer, my system works fine. Yeah, I'm sure it could be better but it it does the job. I can't imagine why that would be a huge issue.  My advice is don't get hung up on the details.

If you use 5" pipe you're stuck with metal and lots of $$$'s.


----------



## Alan72 (Oct 31, 2012)

When I setup my SDD I ordered 10 feet of 5" hose from Penn State industeries and it was worth every penny. I don't think they sell it anymore but found some on Woodcraft site.

ww.woodcraft.com/products/flexaust-5-x-10-feet-clear-dust-collection-hose?gclid=CO2_v6n449ICFUJEGAod8l8G4Q


----------



## Alan72 (Oct 31, 2012)

https://www.woodcraft.com/products/flexaust-5-x-10-feet-clear-dust-collection-hose?gclid=CO2_v6n449ICFUJEGAod8l8G4Q


----------



## kelvancra (May 4, 2010)

Just for reference, regarding 6" vs 5" inputs, I'm running six inch hose to my SDD and just cut some plywood into a ring to fill the gap at the SDD.

Since I have to four bag Jets now (actually, one with bags and one with canisters), I'm thinking of buying the SDD XL for the six inch hose. The other Jet will get moved into the next room and up about four feet, so I might switch to five inch hose for that one. That and canisters would make that side of the shop pretty efficient too.

P.S. Consider cutting a slot about four inches wide and riveting and caulking plexi to the side to allow you to monitor levels. Even with a Home Depot clear, flimsy lawn bag [and a cage holding it], I can see quite well.

When it comes time to empty the bag, lay the can down so the dust flows out, or you'll rip the bag trying to lift it out.


----------



## DylanC (Jan 29, 2011)

I am in the process of building a small 2 stage system using 4" SDR and a Super Dust Deputy. I found that a Fernco 1059-44 works perfectly to fit a 4" SDR fitting to the 5" SDD inlet. Fits like a glove.


----------

