Dust collection decision

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Blog entry by Furnitude posted 09-27-2016 07:45 PM 805 reads 0 times favorited 8 comments Add to Favorites Watch

I’m finally getting serious about dust collection and am going to buy a cyclone machine. I’ve narrowed down the brand but I haven’t decided whether to go with the 1.5hp model or the 2hp model. The 2hp is about $400 more expensive plus it adds the expense of running 220 wiring into my basement. I’ve got a full array of machines and know the basic CFM requirements for each. I am a one-man operation, so only one machine will be going at a time. The 1.5hp model I’m looking at creates real CFM of 900 and nominal CFM of 1314. Now, the 900 is plenty to handle any one of my machines, which aren’t industrial. My jointer is 6” and planer is 12” The 2hp model creates real CFM of 1166 and nominal CFM of 1740.

I want to do this right the first time and don’t want to be disappointed that the system isn’t adequate. I would love to save the $500-$600, but I’m willing to spend it if it makes sense. My questions are, is the 2hp model overkill for my small shop? Or would I regret it if i didn’t bite the bullet and spring for the 2hp? Would the 1.5hp be well suited for my needs?


-- Mitch, Also blog at

8 comments so far

View Redoak49's profile


4729 posts in 2759 days

#1 posted 09-27-2016 08:47 PM

I think the real cfm numbers you quote are a bit optimistic. You should do a search on dust collector testing.

Wood magazine did testing in 2008 which provides good info.

View Furnitude's profile


380 posts in 4277 days

#2 posted 09-27-2016 09:31 PM

Yeah, those numbers are marketing numbers and I don’t expect them to be that high. But regardless of the exact number, my question is whether a 1.5hp cyclone is fully adequate for home shop machines.

-- Mitch, Also blog at

View Manitario's profile


2816 posts in 3653 days

#3 posted 09-28-2016 12:06 AM

My 5hp cyclone with a 15” impeller only makes ~1000 cfm on the shortest run with 6” ducting so I doubt that those numbers are anywhere close to real world. Most DC companies post ridiculous numbers (similar to the crazy HP numbers put on shop vacs) that have no real world value. Real world CFM is dependant on a couple of things; primarily the setup of your system (short runs of 6” ducting, minimal flex duct etc.) impeller size (larger impeller = more airflow) and HP of the DC (higher HP means better CFM at higher static pressure). The best place to start in figuring out what size of system you need is to look at what your duct setup will be and figure out what the static pressure will be for your system. This will give you an idea of what size of DC you’ll need to have to achieve appropriate CFM at each of your machines. Bill Pentz probably has the most user friendly static pressure calculator:

-- Sometimes the creative process requires foul language. -- Charles Neil

View magaoitin's profile


249 posts in 1720 days

#4 posted 09-28-2016 03:31 PM

I am no expert by any means on dust collection, and have only just started to read and research the design of systems. And there are a ton of questions to ask. What is the longest run from the collector to the machine, are you planning on using true wye’s or T’s for the transitions, how many hard 90° corners do you have, are you using what are called “long sweeps” for the corners or the box store, off the shelf 90°…and on and on.

From what I have read so far one of the keys to optimizing smaller (1 to 1.5 hp) systems is to invest in good quality blast gates and making sure every joint is sealed. The more you can seal off unused sections of duct with blast gates, the more of the main CFM power can be directed to the machine you are working on. on smaller HP-CFM systems the key to to minimize or eliminate ALL wasted suction. Bleed-off is the proverbial stake int he heart of a 1 hp blower motor.

Also invest some time building the Thien baffle for the collector. It is inexpensive to build and I would rate it at #2 or #3 on a list of the top impreovemtns to a collection system

I have seen a 1 hp Harbor Freight blower with 4” main lines and 2” branch, in an 18’ x 18’ space that keeps up with all of the mid-sized tools (like those you listed, 12” planer, 10” table saw and a 6” jointer.)

Just my 1 cents worth

-- Jeff ~ Tacoma Wa.

View pintodeluxe's profile


6150 posts in 3584 days

#5 posted 09-28-2016 04:56 PM

A 1.5 hp machine will handle almost any single tool, attached directly to the tool with a short run of flex hose.
If you’re going to hard pipe a system of any length, I would get a 3hp model.

It all depends how you want to use it. If you are always going to move the hose from tool to tool, you don’t have to worry so much about power. In that case focus on separation and filtration specs.

-- Willie, Washington "If You Choose Not To Decide, You Still Have Made a Choice" - Rush

View Furnitude's profile


380 posts in 4277 days

#6 posted 09-28-2016 06:08 PM

I appreciate the information, guys. I also appreciate the work going into calculating how to optimize a collection system. My problem is that I can’t afford a 5hp machine and don’t have the room for it. I can afford a 1.5hp machine and could maybe stretch to a 2hp machine, but that’s it.

I’m going to have a main line of 6” diameter duct. For drops, I will use the largest duct I can that will allow me to connect the different size ports on my machines. I will use Wyes and 45 degree elbows. I will use the best blast gates I can find (and afford).

I think the answer to my original question is—get the biggest machine you can afford that will fit in the space.

-- Mitch, Also blog at

View SFP's profile


36 posts in 2026 days

#7 posted 09-30-2016 12:31 PM

Definitely get the largest collector you can get and fit in your shop. You are talking about your health here!

View Furnitude's profile


380 posts in 4277 days

#8 posted 09-30-2016 02:04 PM

I have a new theory I’m working with. Something was nagging at me and now I realize what it is. For one thing, my chop saw is one of the worst creators of fine dust, and it’s on the opposite end of the shop from where the collector will go. Because of the layout of my basement, which has several posts in the middle of everything, I have to cluster my tools in two groups. The bulk of the ducting i would have to install would link the two clusters. That strikes me as very inefficient. I would also have to reroute some HVAC duct and relocate some lights to run the HVAC duct across the space. There is also the added expense of installing a 240 service. I’m getting an estimate but it’s at least $200 and maybe more. If a 1.5 hp system would be inadequate and a 2 hp would be ok but not great, then I was looking at the possibility of a 3 hp system, which would break my budget.

So… My new idea is to get two collectors—one on each side of the room. These would not by cyclones but the Jet or Powermatic collectors with the internal vortex cones. They would be within 5-10 feet of each cluster of tools. I wouldn’t have to run duct across the room. I wouldn’t lose air flow through all that duct. One cluster (A) has a chop saw, band saw and spindle sander. A 1.5 hp collector right next to them would be more than adequate. The other cluster (B) has the table saw, planer, jointer and router table. That requires a bit more flow. I’m thinking of getting a Jet Vortex 1.5 machine with 2 micron canister for cluster A. An identical machine would probably be fine for cluster B, but I’m also considering a Powermatic TurboCone with 1.75 hp for that one. The PM machine has a larger impeller and is a really high quality machine. So for the price of the ~$1500 2hp machine I was going to get, I could get to Jet machines for $1400 or one Jet and one PM for $1550. The two-machine set-up would be drastically more efficient. It would actually save me money because I wouldn’t have to install much duct (I could actually use some that I already have on hand) and I wouldn’t have to pay for the 240 service. My only concern—and it’s tiny—is that I like the bins of cyclone machines better than the plastic bags of these models.

-- Mitch, Also blog at

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