# Question for Cyclone Owners



## GPDMTR25 (Jun 21, 2010)

I'm wondering what HP (horsepower) people are using for their cyclones in the garage shops.

Recently Finewoodworking wrote an article stating a garage workshop only needs a 2HP but then the article states even with a 2HP you should install your most dust making equipment as close as possible to the cyclone.

I would like to know what HP your cyclone is, does it work, are you happy with it or would you purchase a different HP if you had the chance. Did the footprint of the cyclone helped in your decision?

Also I would like to know the size of your workshop, what size are your ducts and what material you used for the ducts (PVC or metal).

I don't want to start an argument, so please be respectful about commenting on a person's decision on what cyclone they purchased. I would like people to answer honestly and not worry about what others will say about their decision.

Thanks 
Angela


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## Grandpa (Jan 28, 2011)

I read that article with great interest because I am in the process of getting up the nerve to buy a collector system. I think there were some errors in that article and a retraction was written. It was floating around on LJ. I will say that for the cost of many of the 3 hp units you can buy a Clear Vue 5 HP unit. I don't work for any company so this is not an endorsement nor an advertisement. I am looking at this unit. It is also made in the USA. another plus for most of us. Go to their website and check them out. They have filter upgrades for a minimal charge also.


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## GPDMTR25 (Jun 21, 2010)

I've heard of Clear Vue but don't really want to get into brand names in my question because I don't want to raise a heated (and I mean heated) debate. Oneida-air is also made in the USA and compares themselves to Clear Vue on their website.

*But again I didn't want to talk about the possible name brand instead I would like to know what HP people are using and if they like it.*

Thanks
Angela


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## Sawkerf (Dec 31, 2009)

I think that a better question would be the cfm rating of the DC. Air flow rate is more a function of the impeller design than the HP of the motor. IOW, a very efficient impeller with a lower HP motor can provide the same air flow as a less effecient impeller with a higher HP motor.


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## JAAune (Jan 22, 2012)

I wouldn't recommend anything under 3HP for a cyclone unless you are able to keep the pipe very short and straight. We do have an older 2HP unit at work and it provides fairly good extraction but the main line is only about 8' long with short lengths of flex hose going to the machines. It doesn't have HEPA filters either so that's likely another reason why it is able to pull decent cfm.

4" pipe will cause about 20% more static pressure loss than 6" will according to my Dust Collection Basics book. I'd therefore consider 6" to be the better option for large machines even though it is more expensive.

Based upon my experience with the machines at work and recent research, I'm tottering between 3 and 5HP for my personal shop (22'x13'). I'll have 6" pipe running to the tablesaw and chopsaw hoods. At the bandsaw I'll likely branch it into two smaller pipes and collect at the back rear and right under the blade. When I get a jointer and planer those will get 6" lines. The router table will get a branched line like the bandsaw.

In the end, the power needed in the collector depends upon what standards you are shooting for. The above mentioned book states that a tablesaw only needs 350cfm. Bill Pentz recommends over double that amount in order to capture all the fine, invisible dust. Considering that I usually end up working with all doors and windows closed to keep noise down for neighbors I'm going with Pentz's recommendations.

What you really need to do is get the charts for cfm at static pressure to see how well a particular collector will perform with the ductwork you intend to run. Each collector is a little different and will have different statistics.


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## NBeener (Sep 16, 2009)

I think *JAAune* has it dead right.

There IS a science to dust collection. Any of a few of the good basic books will walk you through it, and … when followed … the results seem good.

It's VERY much like HVAC systems, where the heat gain/loss is calculated, then the proper ductwork to provide the necessary CFM to each room, then the hardware (furnace or a/c unit) size is calculated to provide the right CFM, in light of all the ductwork and the static pressure IT provides.

In woodworking, each machine has a specific CFM requirement, for adequate dust collection. CFM requirements drive port size.

Duct length, material, wye's, bends, drops, hose, and all other "plumbing" bits introduce static pressure. Static pressure has a direct impact (lowers) on CFM.

So … you need a DC that will create enough CFM to overcome the static pressure in your system, and provide adequate CFM at each machine. Whether or not it's been measured and published, each DC will have a "fan curve" that indicates the CFM it will produce, relative to static pressure. This, too, is important.

You can even Google "dust collection system design," and get to a number of sites that will walk you through the math.


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## Sawkerf (Dec 31, 2009)

Beener -
It definitely is a science, and it's called Fluid Dynamics (air is a fluid). Once upon a time I was pretty good at it and it got me thru the Mechanical PE exam. - lol

The piping and "plumbing bits" introduce head loss which degrades the flow. Even a straight section of pipe introduces head losses with each foot of its length. Smooth walls are far better than rough walls (laminar v.s. turbulent flow) and changes in direction (elbows, wyes, etc) introduce head losses significantly greater than their actual length.

The exhaust filter is another (often overlooked) factor in the overall flow. As dust builds up, the flow drops (think of a partially closed valve), and the overall system performance goes down. This morning, I emptied the collection bag on my 1100 cfm DC and cleaned the pleated filter. I regained ~25% - 30% of my "normal" flow. Between cleanings, I give the filter paddles several turns every day or so, and can really notice the improvement in flow.


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## NBeener (Sep 16, 2009)

A good intro to the calculation process can be found here.


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## JAAune (Jan 22, 2012)

For those working alone in the shop it's important to note that the article NBeener linked to mentions that the duct diameter never increases when a line to a non-primary machine enters the main trunk. This is important because the lone woodworker will never use more than one machine at a time and therefore pipe size should probably remain constant throughout the whole shop. The exception to this would be when branching into multiple lines to collect at two sources from a single machine.

Note that the article defines "primary" as the machines that are likely to operate at the same time.


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## jusfine (May 22, 2010)

I have an Onieda Pro cyclone (about 12 years old), I belive it is a 3HP but could be 2HP.
My shop is i*n the loft of our barn*, cyclone is mounted on main floor, *ducting runs under the floor,* and through the floor at the appropriate machines.
We have a 7" main, two 5" runs (jointer and thickness planer), the rest are 4", all spiral metal ducting.
Shop size is 44' x 40' (+ -), and have about 160' of ducting off of the main (30' long).
Each machine has a blast gate, only one or two machines are running at the same time.

I have excelllent collection to all machines, planer, jointer, tablesaw, router tables (2), sanders (2), bandsaws (2) and drill presses, as well as a sweep.

Had a mechanical trade install it, he had done a few designs before mine.

*Very pleased with the performance and would recommend the Onieda brand.*


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## kizerpea (Dec 2, 2011)

it is correct…if the filters are cloged, or u dont have enough filter to prevent back pressure, that is most of the time over looked, your system will preform poorly an it don,t matter what name brand u buy. the results will b the same.
as for me i proly have too much filter…if there is such a thing.the rule of thumb is 1sq ft of filter for every 10 cfm
My filter is 66in long by 10.1/2 dia .


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