# 2 blowers, 1 filter



## David Justice (Dec 14, 2016)

I hope this is clear. Can I have 2 blowers, *not used at the same time* blowing into the same filter/bag?

So, a Y going into the filter/bag unit coming from 2 different blower/motor units? does this make sense? Is this doable?

I can't think of any reason why this wouldn't work, but wanted to check with the group before actually building.

Thanks!


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## jmh547 (Mar 6, 2017)

If you have one running and the other not running I would think you would run the potential of feed air and dust back through the other blower... unless you have blast gates between each blower and the Y.

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## m.n.j.chell (May 12, 2016)

What jmh said. 
Yes, you could vent two systems into one catch bag, but you'd need "check valves" in each one. Like dryer vent flappers, they only need to be operated by gravity (closed) and air pressure. But you'll want them accessible, too, since they'll need to be cleaned once in a while.


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## woodnthings (Jan 24, 2009)

*How about a sketch?*



David Justice said:


> I hope this is clear. Can I have 2 blowers, *not used at the same time* blowing into the same filter/bag?
> 
> So, a Y going into the filter/bag unit coming from 2 different blower/motor units? does this make sense? Is this doable?
> 
> ...


The concept is easy to grasp, but the location of the components is not. Would you blast gate the inlets .rt the outlets? Where in the inlet run are the blowers? The only way to feed one filter practically, is to have both blowers in close proximity, What does this gain you then? May as well blast gate the inlet runs and use just one blower ..... 

Some folks have put 2 blowers inline with one another, but then one wants to "over run" the other. Blowers need some inlet resistance to perform without overrunning, if I understand them correctly...?

See post number 2:
http://www.sawmillcreek.org/showthread.php?24580-Bill-Pentz-on-Dual-blower-Cyclone


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## David Justice (Dec 14, 2016)

*My attempt at a sketch*

I do not want them in-line with each other. they will work independently, not at the same time. they will just be sending dust to the same filter/bag.

Here is a bad sketch of what I mean. A 3HP DC with cyclone going to most machines drawing chips/dust through the cyclone to the filter/bag.

2HP DC going straight from the bandsaw and drum sander (since they mostly produce only dust) to the filter/bag.

By the way, this wasn't just an arbitrary thought. I am getting a new 3HP DC, so I was thinking I would like to also use my old 2HP DC to take some of the load off of the new one. I already have the 2HP all set up where it comes on automatically with the bandsaw and drum sander and works very well with these machines, so I figured if this will work, great!


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## woodnthings (Jan 24, 2009)

*I'm certainly no DC expert ...*

I learned everything I know about dust by crawling under the bed when I was a kid. :grin:

I have 2 separate Jet 1100 DC in my shop. They are both mobile and one runs the table saws and a jointer. The other runs the 24" and 12" drums and the 15" planer BUT they are hooked up one at a time, manually, no blast gates. I use a shop vac on the bandsaws because of the high velocity airflow. I locate the suction right under the lower guides and it gets pretty much all the dust. The bandsaw is a 'sleeper" dust maker. The drum sanders are "dust maker monsters". The table saw is kinda like "not so much" and it's difficult to grab all the dust from under the saw. I've tried different variations on over the blade dust suckers and they work pretty well when hooked to a shop vac.

Planers and jointers generate more "chips" than dust and will fill a barrel much faster. I've also tried different type of in-line separators with varying degrees of success. The chip separators almost double the foot print, and that's an issue in my modest size shop. I do know that the cartridge filters pass more air out than the bags, but they need to be cleaned with the internal flapper frequently.... and I forget. :frown2:

Your diagram is bunched together at the intersection of the components, so it's difficult to tell what is going on and where you may want to install blast gates. I haven't seen gates for 6" or 7" hose, but they may exist. :surprise2: You don't want one blower to pressurize and backflow into the other one on the outlet end, so some sort of gate would be needed. For any real information on DC, I recommend the www.billpentz.com site.


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## m.n.j.chell (May 12, 2016)

*put 'em here*

install dampers of some kind. One way valves.


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