Dust collection again

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Forum topic by DMarusa posted 12-14-2018 02:49 PM 518 views 0 times favorited 5 replies Add to Favorites Watch
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4 posts in 406 days

12-14-2018 02:49 PM

Topic tags/keywords: dust collector two duel double separator collection cyclone harbor freight

Please forgive me for possibly stirring up an old and settled subject.

I have read hundreds of threads about whether or not two blowers can be joined to improve performance. Some say it isn’t possible or it offers no improvement. Some have advised that running parallel verses in series is the only way to prevent motor damage or failure. Others have claimed improved performance (stumpy nubs) running in series. Others have given all kinds of valid mathematical arguments about how any performance gains would be minimal because of other system restrictions… or that the affect would be reduced separator performance.

Now to my question: In all of my searching, I cannot find any conversation about running two blowers, one before and one after the separator (cyclone or thien). I have read lots of information about how a separator… specifically a cyclone considerably reduces cfm levels and I was wondering if this configuration could act more like a booster. So, one unit is pushing and one is pulling. With the separator between the two and the air flow becoming more static, wouldn’t the second unit have a job to do again? And wouldn’t the second unit, pulling from the top of the cyclone reduce some of the back pressure for the first unit, increasing the flow rate making the cyclone more effective again?

Many say that a HF unit doesn’t have the performance to run a decent size cyclone. I happen to have two HF units in the standard rolling cart configuration and was hoping to give this a try.

5 replies so far

View jamsomito's profile


457 posts in 1027 days

#1 posted 12-14-2018 03:32 PM

This is a very complicated scenario to speculate. Generally speaking parallel fans will multiply pressure and series fans will multiply flow. The issue is where your system point falls on the performance cuve – unless they are specifically designed for that configuration and system setup (which is always changing when you open and close blast gates), you don’t know where it will land (or what the performance curve even looks like with the double configuration, the real world isn’t perfect). The concern is overworking the fan motors and killing them or worse, starting a shop fire. I would not trust those HF units to be robust enough to take any extra load. If you do try it, at a minimum have some way of monitoring amperage like stumpy nubs so you can shut it down if things start overloading.

Specifically about your question – connecting one at either end of the line is still a series configuration and will increase flow (provided your pipework allows it) and thus motor load. By moving their locations instead of one immediately after the other, you’re only fiddling with the pressures in the components between the two. I have no idea how that would affect cyclone performance – usually it’s under negative pressure. I would be inclined to keep the status quo for the cyclone design.

View DMarusa's profile


4 posts in 406 days

#2 posted 12-14-2018 07:21 PM

Thanks, Jamsomito. I appreciate your thoughtful response.

View ArtMann's profile


1462 posts in 1417 days

#3 posted 12-15-2018 12:14 AM

If you rig this thing up, you will have no idea whether both machines are sharing equally in the load unless you buy a meter to measure current draw from each. One could be drawing enough current to burn up while the other is barely above idle. Clamp on meters that are accurate enough for your purposes can be bought from Harbor Freight for not too much money. That would be my suggestion.

View Holbs's profile


2257 posts in 2630 days

#4 posted 12-15-2018 01:28 AM

    If you hook up two dust collectors in series, you will create a wormhole.

-- The Carpenter Bee is derived from the Ancient Greek word wood-cutter "xylokopos/ξυλοκὀπος"

View DMarusa's profile


4 posts in 406 days

#5 posted 12-15-2018 03:21 AM

Artman, I purchased two meter panels, just like you suggest. One for each motor. I have a few setups I’d like to try with the meters in place. They are both currently running off of the same 40 amp circuit and by themselves, they are only pulling about 12 amps each and seem to be pretty even. They were both bought new, but about a year apart.

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