Specific Dust Collection Question - Insulated Ducting

[John Akerblom]

I just bought a 5HP Oneida Dust Gorilla Cyclone with all the bells and whistles. I live in Southern California, and will be venting the exhaust directly outside (no filter) via 10 feet of pipe.

My questions is:

Can I get away with using insulated flexible hose to carry the exhaust air and fine dust outside?:
Thermaflex

Model # 0582-0800-0001

Internet # 203766768


MKE 8 in. x 25 ft. HVAC Ducting - R8.0




asdf.jpg

http://www.homedepot.com/p/Thermafle...w&gclsrc=aw.ds

I figure it should be able to handle any positive pressure fine and also help with noise? Or do I for some reason need to use 24 gauge ducting. It seems as this flex duct could handle any positive pressure.

Also, as my cyclone is in the corner of my small, two garage shop, I am planning on wrapping the body with some sort of acoustic foam, leaving the motor exposed for venting. Does anybody have any experience? Currenly leaning towards the Whispermat 2 product from http://www.silentsource.com/barriers...rmat1and2.html

Below is the current diagram of my workshop, the insulated flex ducting I'd like to use would need to make a 90 degree bend to exit the wall.

Dust Collector Setup PDF-page-001.jpg

[Marty Tippin]

Can't say whether the flex duct will work or not, but a smooth-bore pipe would make for less resistance to airflow. You'll have to buy the flex duct in 25 ft rolls so there will be lots leftover. 2 5' pieces of snap-duct would be a lot cheaper.

My only other comment is that a 5hp DC is massive overkill for a shop as small as yours unless you'll have someone running all those machines at the same time...

[John Akerblom]

25ft of Flex roll is $90.
10 feet of 8" snaplock ($60) plus the three Elbow Joints ($50) I'd need to clear my doorway and exit through the wall.

I'm just trying to come up with a way to reduce the decibel level from the exhaust. My exhause port outside the garage vents near my neighbors, who have small children, so the smaller the better.

I realize flex hose has way worse airflow than straight pipe, but figure it shouldn't be that bad for return air (especially since I'm already avoiding the resistance caused by a filter and have an oversized motor for my needs).


Also, I realize this unit is oversized for my needs, but there is not much of a price difference from the 3hp to the 5hp (only $100) and I'd prefer the increased suction to catch fine dust (I'm prone to allergic/respiratory reactions to small airborne particles), especially for machines not designed for optimal dust collection (i.e. lathe and miter saw).

[Ben Rivel]

A different way of looking at it: Im not sure if what youre proposing will work and advise calling and asking Oneida about it, seems to me that ducting might collapse under the pressure a 5HP motor would generate. That being said a different way of looking at it is, you already spent for a top quality, powerful dust collector and you dont have that much involved it doesnt look like from your drawing with respect to drops and runs, so why not order a full, proper metal ducting setup to ensure you have the most robust system you can have! I just got done assembling my 3HP V-3000 for a single car garage shop. Seems overkill yea but Im not going to cut corners to get the build done a little cheaper when I bought and paid for a "buy once, cry once" system. Im going with Oneidas snap-lock 26 AWG metal ducting for all the runs and five drops and I took advantage of the free engineering consultation Oneida gives you if you buy a 3HP or larger dust collector from them. You should do that too if you havent already, if for nothing else just to see what they come back with. Is it all going to be costly? Sure, but once its done Ill likely never have to upgrade or change the setup much unless/until I move.

[John Akerblom]

Yeah, for my main lines and drops I have all 24 gauge snaplock pipes and thicker joints from Oneida, none of those will collapse. I am only thinking about using the insulated flexible ducting to exhaust air outside (instead of the filter most people use). The exhause pipe wouldn't have the negative pressure caused by the motor that is exerted on all the snaplock, it would only have positive pressure.

[Wade Lippman]

A different way of looking at it: Im not sure if what youre proposing will work and advise calling and asking Oneida about it, seems to me that ducting might collapse under the pressure a 5HP motor would generate.

I don't know if it will work, but I can say with certainty it will not collapse.
Oneida will probably decline to comment on systems they didn't design/sell.
I kinda doubt it will work, but don't know.

[John Akerblom]

The 10" stuff is rated at a maximum airflow of 2900 CFM, I don't think the idea is all that outrageous.

http://www.homedepot.com/p/Thermafle...-203766770-_-N

[Jim Becker]

I think you'll be fine for this application, but suggest you upsize to the 10" to help compensate for any loss of frictional efficiency. Be sure you install 'critter guards' on the external end, too.

[Robert Engel]

I don't see a need for insulated duct. If you want to cut down noise, put the unit outside your shop.

Check with Oneida first re: venting outside because there are considerations for your motor pulling too much amperage.

That's a might powerful unit you'll have plenty of room for expansion.

[Ole Anderson]

Your pricing on snaplock seems very high but then I don't live out on the left coast. I see no problem with your solution. 8" is big enough that you won't likely see an issue with back pressure, either too much or too little.

[John K Jordan]

I think that flexible duct would handle the air flow.

However, there is one thing I wonder about: whether high air flow would cause flexing motion or fluttering of the duct. Even a mild fluttering might eventually cause the duct to self destruct. If the air volume and speed were "just right" the fluttering might be severe but I don't know of any way to know without testing. A larger duct might minimize this as would rigid supports along the length. Note that I don't THINK this will be a problem since the inside tube of the flex duct I installed for HVAC in my shop seemed pretty sturdy, supported with strong internal steel spring wire.

I would personally prefer a rigid duct. Your local HVAC guy might make a metal duct for cheap. (He also may have leftover sections of flex if you go with that.)

As for noise abatement, I think I read on the ClearVue forum that a large percentage of the noise came from the exhaust duct so even insulating just it in some way might help a lot. Maybe build a closet around yours too since it is already in a corner? I put my 5HP cyclone and big air compressor in an insulated closet which reduced the noise tremendously.

JKJ

[Dan Friedrichs]

Seems like lots of threads, lately, where people are getting very confused by not reading the OP very closely...

Yes, this should work fine, since it's under pressure. As Jim said, size up to 10" to reduce losses even further. Take care to avoid sharp bends - install support to allow for gentle curves and minimal kinking.

[terry mccammon]

I used on the outbound side as I had some available and it was therefore free. It worked fine and then one day I realized that the small fines headed for my filter had actually worn a hole in the duct. So I went with metal.

[David G. Jones]

I just finished installing a Clearvue 1800 system in an outside shed to control noise and used 25' of insulated 10" flex duct through the attic to return the air to my shop. It really cut down on the noise, but did add about .75" of static pressure to the system. I can't see inside the duct but there is no vibration, and I think it should work OK.

[Jim Andrew]

Better keep the kids and the pets out of your shop, they could get sucked through the dust collector.