Duct-design, materials & suppliers?

[Phil Winn]

I love my Pentz Cyclone, it can suck the chrome off a bumper! Now with the new
tools, I should update the duct-work. Was thinking on placing the cyclone on one
side of the shop, then running a 6” horizontal for 10 feet to a 6” * 6” * 6” wye; the wye drops down to a 6” blastgate, to a 5 foot straight duct, to two feet of flex and finally to the tool. Add a 5 foot 6” horizontal to the 6” wye (and the same to the tool). Repeat as needed for each tool. Now the specific materials; I want to purchase this ductwork once, and have it outlive me.
Duct pipe:
A. Welded Nordfab
B. Snap-lock Nordfab
C. Penn State<ST1:p
D. Oneida-Air snap-lock
E. Oneida-Air Spiral
F. Grizzly
G. Other?
Blast-gates:
A. Oneida-Air alloy
B. Lindab
C. Other?
Wyes:
A. Welded Nordfab
B. Snap-lock Nordfab
C. <?xml:namespace prefix = st1 ns = "urn:schemas-microsoft-com /><st1:PlaceName>Penn</st1:PlaceName> <st1:PlaceType>State</st1:PlaceType></ST1<IMG class=inlineimg title=lace>


<st1:PlaceName>Penn</st1:PlaceName> <st1:PlaceType>State</st1:PlaceType></P>

<st1:PlaceType></st1:PlaceType>D. Oneida-Air snap-lock </P>

E. Oneida-Air Spiral </P>

F. Grizzly </P>

G. Others? </P>

Flex hose: PVC or Urethane? </P>

A. Oneida-Air </P>

B. Rockler or Woodcraft </P>

C. Wynn Environmental </P>

Any thoughts? </P>

Thanks once again! </P>

Phil</P></FONT></FONT>

</P>

[Michael Gabbay]

Phil - I bought my snap-lock pipe and fittings from Oneida. They were actually about the same prices as HD but better quality. The shipping was free at the time. The flex hose that they have, clear with wire ribbing is really nice. I would defintately buy more from them when the need arises. I'll probably reduct some of the tools and order the fittings from Oneida.

Mike

[Jim Becker]

Also satisfied with Oneida on the components and flex...and they will do a pro duct design for you, too...free if you buy a minimum amount of product.

My only other comment is about blast gates. Consider building your own as all the commercial products result in restriction since they fit inside the duct, rather than outside of it.

[Bob Dodge]

Phil,

Here is some information for your duct system.

http://www.nordfab.com/pdf/QF_Technical_Manual.pdf

http://www.nordfab.com/pipe.cfm

http://www.airhand.com/

http://www.oneida-air.com/products/ductwork/main.htm

On the subject of flex hose, you'll find the urethane hose to be much more expensive than the polyethylene vinyl, however, it comes in many forms, such as 2 layer, 3 layer, 3 layer, etc. It's highly abrasion resistant and chemical resistant, but may be total overkill for your shop. Give some thought as to whether those features are important to you.

For spiral pipe, there guys who manufacture this stuff, are everywhere. Usually small manufacturers. Buying directly from those guys will save you a bundle, especially where shipping is concerned. Just contact a local heating and ventilation contractor in your area, to see where he/she buys his pipe. You should be able to get 6" 22 ga.-24 ga. spiral, for about $2./ft. They'll usually have the proper fittings as well. You could also try the Yellow Pages, under "pipe", or "heating and ventilation".

You don't necessarily have to go with all 6" pipe. You can probably run a 7" main to at least your first drop, and perhaps even the second, depending how it's configured, and IF you need some extra "reach" from your system. That'll also depend on your filter back-pressure.

To know at which point you can run 7" main, you have to be able to pull 950 cfm through that 6" drop. That'll give you 3500 fpm in the horizontal 7" main. Don't worry if you're at 3400 fpm, or 3300 fpm for example.

By using 7" from the cyclones outlet, to that first or second drop, you'll reduce resistance in the first few elbows and the 7" pipe, as well as the first few drop elbows. That may or may not be necessary however. Depends on your shop layout.

Blast-gates can be located close to the machine rather than at the top of a drop. Much more convenient for you.

A 7" drop can be configured as all 7" to the machine, or, as a 7" drop, with a 7x5x5 split. That'll give you two 5" take-offs. On a drop like that, place the blast-gate just above the 7x5x5 wye. You want both 5"'s feeding the 7" drop pipe.

You can also have a 7x6x4 configuration. In other words, 7" drop off the main, then a 7x6x4 wye. You could run that 6" pipe to a large planer for example, and the 4" to a floor-sweep. Again, you'd place the blast-gate above the 7x6x4 wye. You want both of those branches feeding the 7" drop-pipe.

As long as the total area in square inches of the branches, equals the area in sq. in. of the drop-pipe, you'll have a very low-resistance, and well-balanced drop. Another combo might be one 7" drop, and three 4" branches, serving a cluster of small machines. Again, single blast-gate, above the 7x4x4x4 wye.

The area in sq.in. of various diameters is,

4"= 12.56 sq.in.
5"= 19.625 sq.in.
6"= 28.26 sq.in
7"= 38.465 sq.in.

The NordFab Quick-lock is beautiful stuff. By far the easiest to assemble, but very pricey.

"Gored" fittings, are usually very heavy-duty, but very expensive to produce.
Long radius turns are also very nice (2.5x diameter radius), but are not absolutely necessary. If you're concerned about 100% efficiency at a particular drop, you may want those, however, if your drop only requires 950 cfm, and you're pulling 1000 cfm as is, the extra cost won't help. They may help if that particular drop is operating "on the margin".

Remember too, you don't need a drop at each machine. You can "splice" into a nearby pipe. Here's an example. Let's say you have a single 7" drop, split with a 7x5x5 wye, and you're running 5" to a jointer, and 5" to a planer. Now you decide to place a drum-sander close to those machines. You can splice into one of the 5" branches, by using a 5x5x5 wye. In that case, you'd need a blast-gate on each branch, below the 5x5x5 wye, since that would be an "either/or" branch.

Good Luck, Bob

[Steven Wilson]

Unless you're running a large motor and high CFM (7.5HP and a 10" main) you really don't need the thick walled pipe like Nordfab or Spiral. The thinner guage snap lock and the adjustable elboes from Oneida are sufficient. I went with Nordfab fittings on the termination of my duct runs to make it easier to connect/disconnect from my machines. I used the Nordfab blast gate adapter extensively and then various Nordfab reducers, machine mounts, and hose adapters to connect from the blast gate to my machines. The bulk of my runs were snap lock pipe. Just make sure to seal them when done. I had Oneida supply my ductwork including the Nordfab. Nordfab is the same price regardless of supplier.

[Allan Johanson]

I'm with Steve. I'm using 28g snaplock for some parts and 28g spiral for the rest. The 28g spiral is super strong and will never die. The 28g snaplock is holding up amazingly well even with my large cyclone. Not one indication it might collapse.

I'd still probably opt for 26g snaplock for extra security, but there is no way us hobbyists would ever need anything stronger than 28g spiral. It's a waste of money. Unless you want to stand on it. :D

When it comes to wyes, folks (myself included) may say to use a 7x5x5 wye, but what you'll find is that sometimes parts like this just can't be found easily. A local manufacturer of HVAC pieces simply doesn't make a 7x5x5 wye. So you'll need to buy a 7x7x7 wye and add on some reducers to get the final size you want.

For flex hose there are different qualities out there. Some are super flexible and you can flex them into tight circles. Some are like a frozen garden hose -barely flexible at all. If you can, choose the stiffer one for extra airflow. The softness of a supple flex hose is nice at times, but it is more restrictive than a less flexible hose. Choose the right kind based on the application.

Cheers,

Allan

[John Bush]

Hi Phil,
I used 24g snaplock pipe and fittings from a local wholesaler. All the fittings are designed for blowing air and we had to "reverse" many of them by cutting off the crimping from one end and add crimping to the other end. It worked OK, but after ordering some special Ys and floor sweeps from Penn State, I realized how much easier it is to use appropriately designed components. Considering the time to pick up the stuff, going back to get the stuff you forgot or didn't think of initially(3 times), and going back to return the stuff you didn't need, I'd recommend having someone(Oneida?) design and deliver the components and then install yourself. I always like learning and doing new things ,like HVAC (http://postfiking.com/?go=hvac), but in reality, I spent much more time, money (http://postfiking.com/?go=money), and energy by trying to figure it out myself and in the long run had less time for using the new toys in the shop.

The 24 g is very strong and 26g would be fine as well.

All seams and joints had to be sealed by painting on a grey sealer-made a huge difference in efficiency.

I went nuts and ordered the Ecogate system for 4 machines. I haven't installed it yet. New TS arriving in two weeks, so I'll hook it up then and let you know how it works.

Good luck, John.

[Chris Padilla]

I guess no PVC for your ductwork, Phil? :) I'm going that route but will mix-in metal as needed (reducers, quick-connects).

[Andy Howard]

I recommend 6" pvc sewer and drain! That's what I used and it is working out great.

A.

[Christopher Stahl]

I'm using S&D as well. Nice and inexpensive. :)

chris