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Oneida Super Dust Gorilla #3: Shop Duct and Hose Testing

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Blog entry by Redoak49 posted 07-31-2016 03:36 PM 1761 reads 2 times favorited 6 comments Add to Favorites Watch
« Part 2: Performance Testing Part 3 of Oneida Super Dust Gorilla series no next part

Several months ago, I purchased the Super Dust Gorilla 5 HP from Oneida. The specifications on the Super Dust Gorilla were:
• 5 HP US made Baldor motor – 19.5 Amps
• Backward Inclined Cast Aluminum Impeller – 15”
• Max Performance 1860 CFM at 2.5” SP
• 8” Inlet
• HEPA MERV 16+ Filter
• Filter 110 sq. ft

I posted a couple of days ago the measured performance curve for this dust collector. That was all fine and somewhat interesting. But, the important part is not the performance curve but how well is works inside the shop hooked to the individual tools.

My shop is about 15 ft by 35 ft with the dust collector located just outside one end of the shop. It is piped using two 8” 90 long radius elbows and then reduced to 6”DWV. The 6” DWV runs for about 12 feet and has drops for the table saw, planer and other larger tools. The next 15 ft is run with 4” PVC.


The testing in my shop was done in a similar manner as described in the previous part of this blog. A digital thermal anemometer and digital manometer were used. The same holder was used for the digital thermal anemometer and six measurements were made across the diameter of the 6” pipe.

ALL OF THE FLOW MEASUREMENTS AND STATIC PRESSURE MEASUREMENTS WERE MADE IN THE SAME PLACE. Different gates or combinations of hoses and equipment connections were made to determine the flows under various conditions. The testing location is shown in the following diagram.

The results are summarized below. Please understand that the numbers on this diagram represent the flow with only that area open. The 1658 CFM was taken at the dust collector with an open 8” duct.

The flow of 1360 CFM was taken at the same testing point from the previous figure and represents just having the 6” Wye open. Similarly, the 1345 CFM flow at the 6 inch gate represents the flow with just the 6 inch gate open.

As one can see, the reduction of the duct from 6” to 4” and the 4” gates reduced the flow down to about 600-820 CFM.

In the first section of pipe my shop, I am using 6” DWV pipe, 6” blast gates and then reducers, with 5” flex hose for the drops to equipment. The following schematic shows the hookup to the 4” port on my SawStop. Again, the flows were determined for each point by gradually adding components. First, a flow measurement was made with just the wye open for 1360 CFM, then the blast gate was added which resulted in a flow of 1345 CFM. Similarly, the 6”- to 5” reducer was added and the flow dropped to 1071 CFM and with the addition of 10 feet of 5” flexes hose, the flow dropped to 900 CFM. Finally, a 5” to 4” reducer was added providing a flow of 720 CFM and when actually connected to the SawStop the flow was 670 CFM.

I got similar flows when hooked up to the dust port of a 15” Jet planer.

As a comparison, I hooked up a 6” to 4” reducer to the 6” blast gate and then 10 feet of 4” flex hose. The 6” to 4” reducer results in a large drop in air flow. But the end result is similar to using the 5” hose and then 5” to 4” reducer. Both provided about 720 cfm at the connection to the tool. I had expected that the 5” hose would perform better but the bottom line is that both are reduced to a 4” connection to the saw.


I have been using the following setup to connect to my planer including the 4” elbow for convenience. The test results show that the elbow results in a 120 cfm drop in air flow and I will stop with this practice.

After the first 12 feet of my shop with the 6” DWV, I am using 4” PVC. This area has my router table, band saw and drill press. The measured air flow to the drops for these machines is 600-800 cfm at a SP of 9.75 – 9.9”. For the time, this is adequate and does a pretty good job. As I work to improve dust collection this may be an area for improvement. However, with the machines only having 4” ports on them, I do not anticipate making any changes in the near future.

One last item….I took all of my data from both the 8” duct tests and the shop tests and plotted the flow versus static pressure. Using Excel, I had a trend line calculated using a polynomial fit. The data fit the curve extremely well. In the future, if I want to know the flow, I can simply measure the static pressure and read the flow from the curve. For instance, if I would read a static pressure of 9 inches, I could look on the graph and find that corresponds to a flow of about 900 CFM.



6 comments so far

View AandCstyle's profile

AandCstyle

3170 posts in 2432 days


#1 posted 07-31-2016 10:09 PM

Just wow!

-- Art

View gschilli's profile

gschilli

1 post in 102 days


#2 posted 08-07-2018 05:21 PM

Thanks for the nice post and thorough testing. I am looking at putting together a setup for my shop and have the DW735 planer. Do you know if the internal blower changes the measurement? Were your values determined with the planer on or off?

View EarlS's profile

EarlS

1763 posts in 2523 days


#3 posted 08-07-2018 05:45 PM

I’m very impressed with the thoroughness of your testing.

FWIW – I asked Dewalt about the DW735 planer. It blows ~200 cfm but they didn’t have a pressure. There is probably a calculation somewhere that can be used to figure it out. At any rate, the fact that the planer is pushing the chips and air actually helps out the DC fan. Instead of a negative pressure at the planer it is positive so the DC fan will be able to pull more cfm and still hold a low vacuum.

I’m curious what the total cost on your system is. I’m thinking about selling my Laguna 1.5HP unit and getting something like this, maybe a 3HP unit rather than 5 HP like this one. I’d have to upgrade one of the circuits to 240V for it. At some point, before I do that, I need to run a set of tests like you did and see what it can do.

-- Earl "I'm a pessamist - generally that increases the chance that things will turn out better than expected"

View Redoak49's profile

Redoak49

3602 posts in 2164 days


#4 posted 08-07-2018 08:54 PM

I did testing on equipment them on. While the DW735 has a 4” port it actually is smaller. Interestingly, with such a small port is does a really good job.

I do not remember the exact cost but the Super Dust Gorilla was around $2200. I looked at the cost of the 3 hp versus 5 hp and it was small. In addition, the wiring I had was adequate for the 5 hp unit. I only bought a few pieces of duct from Oneida and the rest was DWV pipe and fitting that I bought from Menards. All of my blast gates are ones I made and there is a blog about them. I probably have $200-300 in my ducts.

The Oneida unit is pretty tall and was difficult to get the motor up top.

The next comments may cause some to think I am wrong but…

One thing about the 5 hp is that it really sucks. I did not want to have to enlarge my ports from the 4”. With a powerful cyclone I get very good flow with the ports. Everyone seems to say that you have to enlarge the ports. I recommend that you test your system and determine what flow you get with the 4” ports. Then, make a good decision.

View EarlS's profile

EarlS

1763 posts in 2523 days


#5 posted 08-08-2018 11:35 AM

You can get high flow through a smaller diameter if you have the impeller and motor to generate the higher vacuum to offset the pressure drop, which you have. It all comes down to cross sectional area, air flow, and pressure drop. Larger diameter piping means lower pressure drop at higher air flow. You just have to make sure the air velocity is high enough to keep the particles entrained in the air stream.

Too bad most of the DC companies don’t provide good fan curves with examples so the consumer can at least have some hope of buying an appropriate sized DC.

BTW – I’m guessing you are an engineer?

-- Earl "I'm a pessamist - generally that increases the chance that things will turn out better than expected"

View Redoak49's profile

Redoak49

3602 posts in 2164 days


#6 posted 08-08-2018 01:10 PM

Yes, I am a retired engineer. I did the testing because I thought it interesting and would help me with my setup. Also, it might encourage others to do the same. Many people have the HF unit with modifications but very little good data on performance.

The best source for fan curves is Wood Magazine which has written several articles with performance curves.

Oneida does publish curves and they seem accurate. I do not know why ClearVue does not publish curves on their website.

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