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Better impeller for better dust collector performance

33K views 23 replies 16 participants last post by  Learner 
#1 · (Edited by Moderator)
I came across an article online at the American Woodworker website titled "Soup up Your Shop" about half way down on this page http://www.americanwoodworker.com/blogs/reviews/archive/2013/11/12/soup-up-your-shop.aspx they suggest replacing the dust collector impeller with a better one.:

4. Better Impeller. Has your shop outgrown your 2-hp collector? Before you buy a 3-hp collector, consider upgrading the impeller on your old machine. An aftermarket impeller from Oneida Air Systems will fit most 2-hp collectors and improves cfm by 30 to 80 percent. In testing,we found the more you load your collector, the greater the benefit. The large fins offer greater surface area to move more air. Plus, these impellers are statically and dynamically balanced so they run truer and help extend the life of your motor.

Also I found a web site that sells air foils (implellers) http://www.continentalfan.com/ecatalog.php?fantype=industrial&fid=18&s=OEM+%26+Replacement+Impellers

I'm wondering if anyone has tried an impeller upgrade or has an informed opinion on the subject.
 
#2 · (Edited by Moderator)
I worked on a project where granulated plastic (PET) bottles were conveyed pneumatically and the blowers, which were in design the same as what you see on a dust collector, benefited substantially from more efficient impellers. Part of what was needed was to get more life out of the impellers as they were constantly blasted with small, sharp PET fragments. This wore the blades down to the point of failure in less than 6 months resulting in small explosion as the blades (3/8" thick steel) detached from the plate. The other part of what was needed was to increase the air stream velocity to reduce the frequency of clogs. The 40 and 50hp motors were pulling a little over half their rated amperage with the factory impellers, so I specified 22" impellers with a negative hook angle (also better welds between the plate and blades for greater abrasion resistance) to replace the factory 20" impellers. The result kept the motors within their rated load, doubled the time before replacement and increased the air stream velocity by 24%. While a little unrelated, I have tried a better impeller in my two stage snow thrower and the difference was much greater than I expected.
 
#3 ·
I would suggest an amperage check on your DC before you go with a larger impeller. If the motor is running close to full load amps with the existing one, it's quite possible you may overload it by installing a larger one. That said, I replaced the motor on my DC, and it's oversized for the impeller…I wouldn't putting a larger one on, but I was unaware that Oneida sold them as parts (my DC is an Oneida). I may have to check into that. One other caution, following what yeti mentioned: the Oneida impellers are (as far as I know) aluminum ones designed for cyclone use, very little material hits them (in theory). Put one in a single stage DC and it may have a very short life.
 
#4 ·
There are basically three types of impellers. Forward curved blades (your furnace fan) reverse curved blades used in high static pressure systems and flat, no curve, blades used in moving solid objects, like sawdust and chips. The first two types give more air flow but will fill up with debris. Especially the forward curved impellers. So there is a trade off with different impellers. Air flow is not the only consideration.
 
#6 ·
" I know bill pentz is either a love or hate name, but he has done more factual research than anyone I've found. He has nothing to gain, he just want to help people to be safe"

+1….
 
#7 ·
In my search for a replacement impeller, ran across a continental fan impeller for sale from oneida. Says it is made from some type of plastic and is stronger than steel. Looked at the continental fan website, they make larger and smaller impellers, so am looking at their 15.75" diameter impeller. Was considering one from clearvue, and a leeson motor, they say you need a 5hp motor to run the 16", so it would be much too big for the 2hp on my cyclone. I would just like to get more suction, since i got a wide belt sander, could use a bigger cyclone. just don't want to buy a whole system, when I have a cyclone, and appears the bigger motor and fan just improves the function of cyclones, and clearvue uses the same size cyclone as i already have on their big cyclone systems.
 
#8 ·
When you change the impeller, watch the amperage on your motor.
The extra weight and circumference could possible cause the motor to strain a little too hard to get up to speed and could trip a breaker.

Also, the more air the impeller is pulling, the harder the motor has to work.

Another thing to be aware of is that some dust collectors that are rated as 2 hp are actually closer to 1 1/2 horses so they may not be up to the task.
 
#11 ·
The continental impeller is made of plastic, with an aluminum hub, so is light weight compared to the original steel on my 2hp woodsucker. So I think maybe a 14" impeller on the woodsucker could be a big improvement. I called Oneida, but you have to give them your number so they can call you back, and I have been hauling hay bales on an old open tractor, can't hear my phone. Was thinking of selling the woodsucker, and installing a new motor and impeller on a used Aget dustcop cyclone i picked up, it has a longer cone.
 
#12 ·
Tried 3 times in the last couple weeks to talk to a Oneida engineer. Their phone system says to leave your number and they will call you back. Other morning I called early and talked to a lady, she took my information and said she would have someone call me but no call. She did say it gets pretty crazy about 9 am eastern.
 
#13 ·
The topic we are discussing, seems to me, would make an excellent article for one of the woodworking magazines to perform tests on a variety of impellers and publish a write up on the results. I wonder if one of them might be interested.

Phil
 
#14 ·
There's only so much air that can be pulled through a duct of specific diameter. Unless a dust collector was equipped with a poorly designed impeller to begin with, I don't see how changing to a new one will help. How does someone determine if the original impeller was badly designed or not?
 
#15 ·
The amount of air pulled through a duct of a particular size depends on the speed of the air. A different impeller could increase the airspeed, thus increasing air flow.

There are certainly different impellers on the market, and they have a huge effect on air flow. That's why two different dust collectors with identical ducts draw different amounts of air through the ducts. For example, the HF dust collector's impeller is fairly small and poorly-designed, which makes the machine draw less air than competing (but much higher-priced) machines.
 
#18 ·
I would have gone with 6" diameter but I didn t think the HF could pull enough CFM through pipes that large

- SuperCooper71
The larger the duct the MORE CFM (cubic feet per minute) you will get with ANY system, up to some point of course. The larger the duct the less restriction there is. But, I suspect what you're really trying to say is that you won't get enough air speed. For a given volume flow (CFM), a larger duct will have slower air speed. If the speed is too slow, debris my settle in the duct and eventually clog it.

So there is such a thing as too large, but it's not due to CFM, but rather airspeed.
 
#20 ·
A larger impeller will likely give more cfm for awhile. But just be aware that these systems are designed as a unit. A larger impeller will put a lot more forces on the motor and bearings and more than it was designed for. If it was a high quality motor, I would not worry much. If you put a larger impeller on the HF , you need to monitor the motor amps, temperature and bearings.

These threads are interesting. How much time, effort and dollars does it make sense to put into a HF dust collector instead of purchasing a better unit?
 
#21 ·
I would have gone with 6" diameter but I didn t think the HF could pull enough CFM through pipes that large

- SuperCooper71

The larger the duct the MORE CFM (cubic feet per minute) you will get with ANY system, up to some point of course. The larger the duct the less restriction there is. But, I suspect what you re really trying to say is that you won t get enough air speed. For a given volume flow (CFM), a larger duct will have slower air speed. If the speed is too slow, debris my settle in the duct and eventually clog it.

So there is such a thing as too large, but it s not due to CFM, but rather airspeed.

- clin
Good to see some common sense. As said, CFM is good but without proper or enough velocity dust collecting won't be any better.
 
#22 ·
These threads are interesting. How much time, effort and dollars does it make sense to put into a HF dust collector instead of purchasing a better unit?

- Redoak49
So far, my estimate is about $800 savings and 80 hours spent on research and building. ~YMMV

Divide that out and I'm working for $10 an hour.

I've taken technical classes that cost almost $150 an hour, so I consider "earning" $10 an hour and learning about airflow dynamics to be an awesome deal.
 
#23 ·
A larger impeller will likely give more cfm for awhile. But just be aware that these systems are designed as a unit. A larger impeller will put a lot more forces on the motor and bearings and more than it was designed for. If it was a high quality motor, I would not worry much. If you put a larger impeller on the HF , you need to monitor the motor amps, temperature and bearings.

These threads are interesting. How much time, effort and dollars does it make sense to put into a HF dust collector instead of purchasing a better unit?

- Redoak49
Probably like most of us here we're constantly investing in the shop and tweaking it as we go. If I can buy a $100 impeller to upgrade my airflow speed that leaves me with other $$ to buy hardwoods or drill bits or saw blades or, well, my list is long :)

It seems worth it to me, for my hobby, to ask all of you more seasoned dust makers what you think. I'm open to all of it.
This is what my DC looks like now. It works, but like everything it could be better!
Wood Gas Cameras & optics Table Scientific instrument
 

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