DC duct routing question

Doug Shepard

In Memorium
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772
Location
Waterford, MI
I'm still poking about in my garage rafters trying to get my DC ducting in. I'm at my 2nd Wye branch and I've got a question about duct routing. I'd prefer to go with the arrangement in the pic, but the reversing direction aspect of this makes me wonder if there's an inherent problem with this.
DuctBend1.jpg

My alternative is to put about a 5-6' straight run before this Wye, then run about 3' to the left before putting a 90 in to bring another duct run back to the general area that the 2nd 45 degree elbow is now pointing. Right now I'd need about 5' of ducting/fittings after the 2nd 45, the other method would take about an extra 8' or so. Regardless of which method the LH branch uses, the straight part of the Wye will end in a straight ahead run about 5 ft from where I've currently stopped, then take a 90 elbow to bring it down out of my rafters. The near side of the Wye is running back to the DC intake. Both methods reverse direction but the 2nd one would do it with a longer run but maybe the transition is better? This LH branch is one that wont get primary use. My main use down-drop will be the straight ahead one and the LH for the occasions where I've got 2 machines I want to have wheeled out and hooked up to the DC at the same time. Any thoughts?
 
Lemme make sure I understand ... Your DC would be sucking from the top of the pic? Is that what you mean by reversing direction?

If so, that's a pretty big no-no. I wouldn't glue that joint together, just in case you have to clear out a clog due to that direction change.

I'd do all i could to put that wye in the other way, even if you gotta go through some acrobatics. The thought I had was puttin' that wye in a few feet sooner and run a few 45's to the distance you need so that things don't make a sharp u-turn.

----

Now ...

In case i am way off, you might be talking about the mild u-turn. The dc being in the BOTTOM of the pic instead, you're making about a 135 degree turn off the wye. If this is the situation, i think that curve could stand to be more gentle, but I don't think it'll be a huge problem, really.

Ideally, you could use some longer 45's that would make those three turns as gradually as absolutely possible. But I doubt they'd really give you much fits. It's gonna add to your static pressure a little, but not THAT much, i doubt.
 
...
In case i am way off, you might be talking about the mild u-turn. The dc being in the BOTTOM of the pic instead, you're making about a 135 degree turn off the wye.
...

That's the situation - with a 135 degree turn and the suction coming from the near side of the wye. I could probably make the piece between the two 45 fittings longer to get the U-turn happening over a longer section. This was sort of a "let's see what this is gonna look like" assembly. I might be able to put a piece between 12"-24" between those 2 45's (instead of the 7" for the demo pic). Glad to hear your thinking that this isn't going to be a huge problem though.
 
Update

I also posted this question on SMC, and Mr. O'Dell prodded my for a sketch, which I should have included in the first place. Very crude, not to scale, and the reversal angle looks worse than I think it really is, but here's the gist of it.

Duct layout.jpg
 
Man - i bet looking at it from above like that really makes you wish the obstructions weren't where they are ... boy that's poop.

I don't think you've got too much to worry about - if you CAN, try like heck to increase the radius of that turn as much as you can, even if that means ending up parallel to the trunk, snug against the wall.
 
try a double wye instead of the single wye and get closer to your take off doug


Hmmmm. Hadn't thought about that, but do they make PVC double Wyes? I've never noticed any but that doesn't mean they dont exist. The idea has enough merit to call the place and find out though. Thanks.

Editted:
Well the idea had merit but Google searching doesn't seem to indicate there is such a thing as a double Wye with 6" at all 4 openings. Was also able to find the website and catalog for the PVC that my local supplier carries (crestline.com), and they don't make it. 4" pipe double Wyes exist and 6" with 4" at 2 of the exits exist but 6x6x6x6 dont seem to be available. Must be an inherent geometry problem? Oh well - I'll be able to make do with the original plan.
 
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Yes they do Doug

i have one that i got from a local hardware..they ordered it form there supplier, i belivee it was charlotte plastics.. its a 6x6x6 and worked great for my application..it was 35 dollars for it!!! try another supplier.:thumb:
 
Doug,

Sorry to hijack thread for another question, but where are you getting your pipe? Is it 6" ?

I have been looking at HD and Lowes. They have some 6" pipe, but I am confused about schedule 35 ? 40 ?

Like all of us, I think about things a LOT before I do anything. I think I am going to be able to purchase a clearvue in about 4-6 months, so naturally I am thinking about the piping. I am really thinking about 26ga AC duct. I will have very short runs... But that is really a different thread...
 
barte. the differnce is in thickness the scd 40 is for all plumbing applications and the scd 35 is thinner and for sewer only, the fittings dont interchage either but if you look in my shop thread you willsee how i made scd 35 fitting work in a scd 40 fitting.. just for DC thou wouldnt fly in a sewer or plumbing application. i wouldnt suggest using 26 guage for duct work i think they reccomend 24 or 22 guage.:thumb:
 
Bartee, if it helps, McMaster-Carr is in Atlanta, that's where my stuff was shipped from. Pipe from them is higher than what I paid here, but the 6-6-6 wyes and the 45 els were the best price I could find. They don't have the 6-6-4 wyes or the 22.5 els. I found them at one Lowes but at a much higher price. But I only needed a few of them.
Maybe find a few of the manufacturers on line for the pipe, and contact them for a local dealer? (Crestline was mentioned above) Might be worth a shot. Jim.
 
Bartee
I got mine from a local place called Warren Pipe that carries the Crestline stuff. Larry's mention of Charlotte Plastics got me looking over their website and it looks like they have a pretty complete line too - even the 6x6x6x6 Double Wye that appears to be a bit less common (lots of 6x6x4x4 and other variants). Getting some local dealer info from either of them should turn up some other options.

I did locate a local dealer for Charlotte's line, but after getting the drawing dimensions from their site and re-checking my setup, the double Wye isn't going to work out anyway. My unobstructed branching opportunities aren't at the same place going in both directions so I'm still stuck with 2 separate Wye's and will just go with the other plan.
 
[

I did locate a local dealer for Charlotte's line, but after getting the drawing dimensions from their site and re-checking my setup, the double Wye isn't going to work out anyway. My unobstructed branching opportunities aren't at the same place going in both directions so I'm still stuck with 2 separate Wye's and will just go with the other plan.[/QUOTE]

see i am not jist another pretty face doug:D you know what you got to work with better than us, but it worked for me great along with a couple street 45's to get it back to 90 again.. good luck doug
 
Update

Well after all that I ended up just using the first Wye to go downward instead of making a branch with the 135 deg bend. Not the optimum location for that down-tube location but the original planned location had some problems as well. Anyway, I'm getting closer to having my above-the-rafter ducting portion done. Still need to work on the below the rafter down-tube stuff.

This one is looking back toward the cyclone
DuctRun1.jpg

From underneath
DuctRun7.jpg
 
doug, did i see a blast gate up in the attic?

Yup. I have to share my shop with a vehicle so none of my down-tubes are going to be permanent. That means I cant really put them on the down-tubes or I'd have to hook all 4 up just to be able to use one of them. So I followed the suggestion on Bill Pentz site to put them as close after the Wyes as possible. The chain that's visible in the pic is my "remote" switch. I spring loaded the LV blastgates. I don't have the anchor points set up yet, but will have the chains set to hook on to a pin below to hold them closed. Dont think I posted about the LV gates here, but have pics on a SMC thread.

http://www.sawmillcreek.org/showthread.php?t=58586
 
spring loaded works.....being as i can no longer view pics on smc i wasn`t aware of your approach:eek: ....sorry! tod
 
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