broke my foot, came to gloat about it and ask where to find ductwork

[Richard Shaefer]

So I was looking for a used dust collector for my shop so that I could pair it with a dust deputy and a HEPA filter kit from Oneida, becuause something like a big honking single unit cyclone is just out of my price range. Turns out a guy on craigslist had a 2 ho Oneida Gorrilla (but not super?) cyclone for sale for $720, which I promtly bought. He never took it out of the box and he bought tall the trimmings including the drum, wall mount kit, HEPA filter (used to optional maybe?), and remote control. Sucky part came when I was carrying the bits into the shop I stumbled and fell. Now my right foot looks like a black and blue puffy sneaker. yay. It'll heal.

Question I gotta ask is about the ductwork. The unit has a 7" inlet, which is rediculous, but cool. I have a simple duct work run that has a 20' straight shot out of the cyclone and then sweeps down 90* to go 12' down the wall and then sweeps 90* again to a 6' run into the table saw. There will be a double wye on the wall between the bottom 90* to feed the jointer and the planer. Straight run pipe is fairly cheap in either PVC or metal, but the 90* elbows are pricey. nice big sweeping ones are about $40 a pop, from what Iv'e seen. Any cheaper ways to go on this? I'm hestitant to use the segmented adjustable ones from the big box stores that go for $12 a pop. they seem like big flow restrictors.

Oh, and any concerns about bumping the duct work down to 6" instead of following out the 7" inlet? seems overkill for the small run.

[Ryan Baker]

Based on your description, a 6" run would do just fine instead of 7". (Of course, you don't know the real answer without doing all the calculations.) With that much collector and a pretty simple run, you will probably have plenty more CFM than you need, assuming you don't put a lot of flex hose in there somewhere.

For the ducting you describe, you could use metal ducting, even the premium spiral ducting, for less money than plastic, and it will work significantly better. Plastic has a lot more loss than metal. You also get mre choices and easier connections with the metal. As you said, it's the fittings that really add up, whether in metal or plastic.

The parts are pretty expensive just about everywhere I have looked, and there doesn't seem to be too much variation between sources. There are the normal online vendors, but shipping can add up fast. Look around in your area to see if there are any vendors close to you where you could pick it up. It would help if you had a friend in the HVAC business, since a lot of local vendors won't sell to the public.

[Thomas Canfield]

Richard,

I just compleed the installation of my 2HP Oneida that I relocated to new shop from my old shop. I used a 7x6x6 Y two foot from the 7" inlet to allow for 2 sparateduct paths and having both in service at same time. The duct arrangement was done to utilize the original duct and fittings, but I did have to buy a few more fittings and blast gate. I ended up going back to Oneida for the material due to their quality, but the ductwork is expensive. My original installation duct cost as much as the dust collector, sorry to say, but once it is installed, then it is there. It definitely is a good investment to get it installed properly.

[Ole Anderson]

I have a 2 hp Oneida with the 7" inlet. My recommendation is to go with 26 gauge snap lock from the BORG in 7" size for your main run, after all you are talking 38 feet of pipe. Running 600 cfm in a 7" pipe will get you enough velocity to keep things moving without unnecessary friction losses. As for the bends, you only have 2 so go with the long sweep versions. As an alternate , if you can figure out the twisty part of the adjustable bends, get two $12 90's and twist each one to a 45 and put them together to get a nice long 90 degree sweep and save $16 each. Check with your local HVAC supply house or a local ductwork shop for a better price than $40 on a true long sweep 90.

[Chris Damm]

Try googling KenCraft. I found that they had every thing I needed at reasonable prices. I used 6" on my 3HP system and it works great. I ran 8" large radius elbow from my collector and ran a 8" to 6" reducer.

[Peter Kelly]

Straight run pipe is fairly cheap in either PVC or metal, but the 90* elbows are pricey. nice big sweeping ones are about $40 a pop, from what Iv'e seen. Any cheaper ways to go on this? I'm hestitant to use the segmented adjustable ones from the big box stores that go for $12 a pop. they seem like big flow restrictors.

6" stamped steel 90º elbows are around $19-$20 from Spiral Manufacturing. No prices on their site, you'll have to call them. http://www.spiralmfg.com/contact.htm

Larger diameter pipe is always preferable but a 6" system should work fine.

[Richard Shaefer]

thanks guys.
lots of good leads here.

[Ron Natalie]

I order most of my DC fittings from Ken Craft (http://www.kencraftcompany.com). My 7" dust collector mouth I WYED down to two 6" to feed the main trunks through my shop.

[Ryan Hellmer]

Plastic has a lot more loss than metal.

I've never heard that before, what is the cause?

Ryan

[Ryan Baker]

I've never heard that before, what is the cause?

Ryan

Friction. I don't have the numbers handy, but I was reading somewhere that had static pressure numbers for plastic vs. metal spiral and the plastic was significantly worse. I'm sure it varies with the type of pipe. Plastic is probably better than snaplock due to all the disruptions at the fittings. I probably should have said "a little more" instead of "a lot more" loss before. It isn't a big deal unless you are scrapping to remove every bit of loss you can salvage. By itself, it probably isn't a reason to choose one over another.

[Peter Kelly]

PVC drain pipe 90º elbows are too sharp as well. Reduces air flow tremendously.