DC Installation

[Bill Lewis]

since I am going through the process of installing my DC system. I thoought I'd post some tips and pictures.
The picture below was a basic layout that I used to send to Oneida so they could work up a quote.
I also sent them tons of pictures and a 2D layout. I think I overwhelmed them with information, because as good as they are, they still made a few mistakes. Still it gave me a good starting point. Besides I had to edit their list considerably because of the components I already had. When I placed my first ductwork order, I only ordered what I knew I needed and would use.

[Bill Lewis]

Ok, now for some tips and pics

Cutting pipe.
Well I tried various methods to cut snap lock pipe, snips, sawzall, and both band saws (14" and cutoff). None work to my satisfaction, and all of the methods can be dangerous. I recomend avoiding any of those methods
The method that worked the best was to snap the pipe together, mark out the length, drill a couple of overlapping holes and use my handheld jig-saw with a metal cutting blade. Just roll the pipe while you cut. It is absolutely the easiest way to cut pipe, however it is noisey enough to require hearing protection.

Joining pipe.
The "factory" crimp is a wonderful thing, but even it can be stubborn. Before attemping to slip a couple of joints together take a look at the female connection. Hammer out any imperfections, and hammer flat any snap lock joints.
What do you do without a factory crimp? Well there are a couple of methods. One is to buy a set of hand crimpers. they do a good job, and are pretty necessary part of the installation. The down side it they tend to neck down the end of the pipe. The other method is to cut a short section of pipe, cut it lengthwise and use it as a sleeve. This takes awhile longer to make up, but it is a smoother connection. Hammering the snaplock joint to keep the sleever from falling apart is also advised.

Attaching pipe together.
I've done a fair share of sheet metal work, and I have used both self tapping hex head screws, and pop rivets. This time I used pop rivets to join the pipe and fittings. The key to making pop rivets so much easier than screws also provides a tool buying opportunity... An air riveter. I got one from the local harbor freight store for $32 (plus $6 for a swivel). It is a one handed operation that can't bite you like a manual riveter can. It is alot easier to drill a 1/8" hole over your head, at some weird angle than to drive a screw.

Mock up before fastening together.
Given that my system was running through walls and ceiling I really needed to do this. I mocked up every run and branch before making the final fastening and taping. Then I could cut pipe to the proper lengths, and build subsections, sometimes rehearsing how things would go together so I actually could fasten them.

Don't be married to the design.
I made several minor changes along the way to the orginal design, that have made the system more efficient, more flexible, and cost less. Have a plan, but plan as you go. Taking your time during install really helps with this.

Make the system tight. A tight system will be more efficient.
Obviously you have to tape the joints and it's pretty well understood that foil tape it the thing to use (not duct tape). to make this go easier, first wrapped a joint with some tape to find the lenght needed to give one full wrap, plus about 2 inches for overlap. I then laid it out on the bench and marked it for pipe size. For every 1" pipe size greater or smaller, measure out 3 1/8" (1 pi) more or less as needed and make another mark. Then if you need a bunch of 6", or 5" or 4" tape strips all you have to do is pull it out and cut it scissors.
Listen to your system with all of the blast gates closed. You can hear the leaks, if necessary put some silicone caulk on loose rolled joints like the ones on adjustable elbows.
I also, just siliconed, and riveted the blast gates directly to the pipe.

[Bill Lewis]

This picture is the X10 wireless receiver the 20amp appliance module, and a couple of keychain remotes that I have.
Interesting thing, the outlet for the receiver is wired in to a different main panel (we have 2 200 amp panels) than the appliance module. I expected I my have a problem with this, but it has worked fine.

[Bill Lewis]

This picture shows the utility closet that will conceal much of the piping. I intend to branch off to the right to go over the other cabinets, instead of using the elbows that are shown.

[Bill Lewis]

This branch will be shared between the jointer and the bandsaw, and will have a floor sweep.

[Bill Lewis]

This drop is the only one that is 4". I used a tapered joint so that it can be shared between the drill press, and the (hardly ever) used lathe. The other wye at the top of the picture will go to the miter saw. The suction is still incredible at this stage.

[Mark Duksta]

Bill,

Thanks for sharing. I just got my Oneida hung up on the wall. I'm about ready to start piping. I'm waiting on Oneida to get back to me with their design. How long did it take them to design your system? It's been about a week and a half since they got my layout.

Mark D.

[Bill Lewis]

I was told upfront that it would take 3 weeks for the design, and that's exactly how long it took. However a subsequent re-design only took a day.

I thought 3 weeks was a bit long considering how much design material I had already forwarded to them (maybe too much), and the fact that I too had already purchased the unit (not just the $100 purchase or deposit).

It's taken a bit longer to do the install than I hoped, but I really haven't had any more time than I have been able to give to the job anyway. So I doubt I could've done it any quicker regardless.

I just placed an order on Sunday for (hopefully) the last ductwork. I got an email to confirm the order, I asked if they could expidite it, and I got a nice response about seeing what could be done.

All in all, a good company to do business with. Very personal service. They remember their customers and both return and initiate phone calls. Their duckwork is very competative with other mail/online especially if you factor in the free shipping for over $100 purchase.

[Allan Johanson]

Thanks for your posts and tips, Bill. It should really help some folks out. I'm about done with my testing and am starting on my permanent ductwork installation and have found the joys of trying to hook up some metal pipe to fittings like reducers.

I tried to buy a set of crimpers but haven't found them yet, so in a couple places I've resorted to using needle-nosed pliers and making my own crimped end. You have to be careful though. It can get ugly in a hurry.

Another thing I did when trying to maintain a flush joint in my main duct was to cut some scraps of metal ductwork and screw it on both sides of a joint between two pipes. Kind of like a coupler that fits over the pipes to be joined.

At times I've also installed some thin metal foil tape on the inside of the ductwork to help smooth out transitions. I don't know if this is a good idea or not. I'm hoping the tape doesn't come loose and create a clogging problem. I think it should be OK because this particular tape I'm using is very good and shouldn't come loose like the cheaper brands of duct tape.

When working with metal ducts and metal foil tape you should wear gloves like the Mechanix line. Well-fitting so you have good dexterity and will help stop cutting your fingers from the ductwork and even from smoothing out the metal foil tape! That tape can be pretty nasty.

When my ductwork is complete then I'll apply HVAC high velocity sealant on all joints followed by metal foil tape. I hate leaks.

I've got to build a half dozen 7" blast gates too. Lots more work to go.

Cheers,

Allan

[Chris Padilla]

Bill,

Out of curiosity, why didn't you go with S&D for your ducting for the DC? I'm still up in the air with plastic vs. metal.... In general, plastic is cheaper than metal but metal has more choices and sizes.

Very nice write-up...looks like a good system.

[Karl Laustrup]

Thanks for the thread Bill. And for your insight also, Allan. I have bookmarked your thread for later use.

I'm waiting on the weather so I can build a shed for my Oneida 2HP commercial outside. I haven't even ordered the ductwork, but I will say that Heather called me to inform me of the price increase that went in effect at the beginning of February, so that I might purchase at the old price. Couldn't do it.

And Mark, it took my design about 3 weeks also. And they didn't tell me it would take that long. At least I don't think they did

[Jim Becker]

Bill, nice job. I also used pop rivets, but only on high-stress points. Everything else is just the foil tape...which has been convenient as the system has changed several times over the past few years due to new tool aquisitions and shop expansion. You are right about using the saber/jig saw for cutting the pipe, too...much better than the other methods.

Allen...my crimper came from Home Depot.

J

[Bill Lewis]

Let's see, first of all, I too bought my crimpers at Home Depot. It might be close to 10 years ago that I bought them, but I'd be surprised if they don't still have them.

S&D pipe.
There are several reasons I chose for not using it.
Cost.
I haven't priced it out recently, but I'm not sure it would be all that less expensive than metal. When you start getting in to pipe sizes greater than 4" it can get expensive, or at least comparable to metal, especially when it comes to large fittings.

Limited size availability.
I'm sure you can get S&D in even increments (over 4"), but not sure if it is available in 1" increments. Even so, there are more fittings involved in transitioning from one size to another.

Static.
No, I'm not talking about blowing up the shop or anything, but plastic does build up a charge. I've been zapped by shop vac hose while sucking up drywall dust. Who wants to live with that. Yes you can ground it, but that just adds another step to the install.

Frictional Losses.
Your system will incur more frictional losses with plastic vs. metal. This occurs in both straight pipe, and fittings. As a guess I'd say that it's probably at least 10% difference. Which means that a 10' plastic pipe is equivalent to a 9' metal pipe. Just a guess at the numbers, they could be even greater. The tight radius on fittings, and the irregular transitions at the joints will incur even greater losses. Another example, If recall correctly, the engineer at oneida told me that 2' of flex hose was equivalant to 10' of pipe due to losses. This adds up and can decrease the efficiency of the system.

Karl, one of the reasons I went ahead with the system order was to avoid the cost increase. It actully worked out pretty well having the system early.

I think I riveted every joint, No fewer than 2, no greater than 4. Removing foil tape can be a bigger pain than drilling out rivets , but your right Jim, I probably could've gotten by without riveting every joint. It's just so easy with the air riveter.

Gloves, yes I forgot to mention gloves. Acutally I use some nice heavy smooth-leather gloves. I'd think that the fabric back on Mechanix gloves might tend to get snagged. Either way, hand protection is an absolute must when working with sheet metal.

One other thing I forgot to mention, probably because I didn't have any, but wished I did. It would be real handy to have a couple of those Craftsman strap wrenches to make adjustments on large adjustable elbows. Those things can get stuck, and they're a pain to handle.

[Brian Buckley]

Why does Oneida not recomend spiral pipe for any system under 5 HP?

Brian

[Jim Andrew]

Just was reading Bill Pentz site yesterday, the S&D pipe is supposed to
have considerably less friction than metal, and fewer leak problems. The
static is a problem, but he says not enough to cause a danger of fire. Jim