# Plenum box or Existing Vortex Ring?



## Tfeni52355 (Aug 7, 2020)

I am going to take my existing Jet DC-1200 DC and create a permanent system for my small shop using a super dust deputy cyclone and Wynne filter assembly. There's lots of YouTube videos and sites (Pentz, Oneida) that have great information. The only real question I have left is: Do I build a plenum and line it with carpet to keep noise down and attach the canister filter to it? Or do I use the existing DC Cyclone and make an adapter for the canister filter as has been done may times? 

My thought is that the existing DC cyclone may create another vortex to allow more of the "fine" dust to fall out. But not having built one of these systems before before I have no idea if there is an advantage one way or the other.

The plenum will have more volume and slow the air down before it enters the filter (theoretically) and may therefore do a better job of allowing the "fine dust" to settle. 

I'm leaning towards the plenum since I can make a large one that will give better noise control but don't want to overlook the real purpose of the system which is dust collection.

TIA, thoughts and guidance are appreciated.


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## difalkner (Nov 27, 2011)

I never thought about lining the plenum with carpet, I'll have to do a little reading on that. Seems to me it would inhibit flow more than you'd want but that's just shooting from the hip. Also seems like it would make it quieter like you mention but at what cost, if any, to the performance...?

David


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## HoytC (Dec 30, 2019)

A large enough plenum will definitely have a lot less loss than the OEM separator ring (aka "bag holder"), even lined with carpet. You won't see a lot of performance difference though if you keep using 4" hose for intake. The SDD has a 6" outlet so you can get rid of the inlet splitter and go straight to the cyclone. Even better, a SDD XL would let you use 6" duct in the intake side instead of 5".


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## woodnthings (Jan 24, 2009)

*Do NOT line it with carpet ......*

The air needs a smooth surface to flow around and a cyclone or helix is the best shape. Do more research on dust separators and you fine smooth ones like this:






Also called Thien baffles:






To deaden the sound you can cover it with carpet or other insulation, BUT the most sound in not coming from the rushing air. It's comming from the impeller and motor spinning at high RPMs. You could locate that part of the system in a different area like a closet or other enclosed space.


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## Tfeni52355 (Aug 7, 2020)

*Add a Thein in place of plenum?*



woodnthings said:


> The air needs a smooth surface to flow around and a cyclone or helix is the best shape. Do more research on dust separators and you fine smooth ones like this:
> BUILD: Dust Separator - YouTube
> 
> 
> ...



Are you suggesting adding a Thein in place of the plenum? This would have both the SDD XL 6" Cyclone and the Thein. Maybe that's the best of all!


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## HoytC (Dec 30, 2019)

Thein baffles have a huge loss coefficient. The design was originally for use with a shop vac which has a lot of static pressure available. It's really not appropriate for use with a low pressure dust collector.


There is absolutely no advantage to adding a Thein to a SDD. It will only cause a big loss in performance.


A hose directly into the filter is the best option, like a typical cyclone configuration. The plenum approach is almost as good. Inside the plenum the velocity is low enough that the carpet will add only a small resistance. Much, much less than a thein baffle.


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## RepairmanJack (Aug 4, 2013)

here, here. I like the separator, but my 1hp system is almost useless with such a collector/separator. Another member said that it was like adding 65' of 4" pipe to your system


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## woodnthings (Jan 24, 2009)

*side by side comparison video*



HoytC said:


> Thein baffles have a huge loss coefficient. The design was originally for use with a shop vac which has a lot of static pressure available. It's really not appropriate for use with a low pressure dust collector.
> 
> *
> There is absolutely no advantage to adding a Thein to a SDD. It will only cause a big loss in performance.*
> ...



I posted the Thein video to show a smooth internal transition, as opposed to a carpet lined one as I stated above. I was NOT advocating the Thein baffle over a cyclone.

Here's a side by side air flow comparison:


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## Tfeni52355 (Aug 7, 2020)

Installed my re-worked Jet bag style dust collector to a wall mounted Oneida 6" XL cyclone and Wynn Environmental canister filter. As you can see from the photos this assembly is shoe-horned into the corner of my garage shop. I used a pulley hung from the ceiling joists and some muscle from my neighbors to help me get it in place. There are only inches of clearance on any side so it was a planned, then re-planned, then re-measured and re-planned process. The weight of an assembly like this is serious so take note. I installed the canister filter and the cyclone/dust collection can after the blower and plenum assembly were mounted securely. I have not installed the 6" metal ductwork yet. That will come over the next few weeks. Three drops will be installed. 

I can say that the plenum does not have a great affect on noise reduction. The plenum is lined with two layers of commercial low pile carpet with a rubber backing. I measured dB's before (Jet floor mounted bag filter) and after (wall mounted blower/ cyclone/plenum) and I got mid 80's dB on my meter for both readings. So if I had to do it over I would probably just pipe the blower into the filter and save myself hours of fabrication time. 

Picking up some precious square footage in my shop is huge though! So glad I did this.


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