# 2 Dust Collector motors on same system?



## NVCowboy (May 24, 2012)

I was given a 1hp Harbor Freight DC intended for a collection/filter bag, but there was no bag. I purchased a 1hp Delta DC with the single micron filter bag and a plastic bag for collection. I am plumbing the Delta collector with a 18' four inch main line that is only 18" off the floor so I do not have to overcome alot of vertical lift. Can I use the gifted DC motor on the far end of the system as a pusher fan to add airflow, or will it create a dead space in the system? Amps are not an issue, as I designed the shop with plenty of extra circuits :thumbsup:. Here is a text schematic of what I am thinking:

DC pusher -> pipe -> tool inlet -> pipe -> tool inlet -> pipe -> tool inlet -> pipe -> tool inlet -> pipe -> Suction DC w/ filter. 

Later, and stay safe.
Bill


----------



## rrich (Jun 24, 2009)

At some point in the system the pusher airflow will overcome the sucker air flow. What this basically means is that the sucker won't be sucking fast enough and the pusher is going to build up pressure. Unfortunately the pressure is going have to go SOMEPLACE. That someplace is into a tool dust collection chamber and then out around the cutters and eventually into your shop or face.


----------



## NVCowboy (May 24, 2012)

Makes sense now, because the bag side is pushing through the filter and the pusher side has no resistance to speak of. Figured there was a problem with this idea, as I had to be over looking something. Applied physics not my strong suit. 

I know everyone runs thier pipes way overhead, but is there anything wrong with going low to keep the vert down to a minimum? Its running down one wall and has approx four inlets. 

Later, and stay safe
Bill


----------



## DST (Jan 10, 2011)

I ran most of my pipes along the walls a few feet off the ground and am happy that way


----------



## WillemJM (Aug 18, 2011)

You can put the two blowers in "series", or in "parallel".

Series means the inlet of the first blower is connected to your system piping which connects the collection points, then the outlet of the first blower is connected directly to the inlet of the second blower and the outlet of the second blower is connected to your dust filter or bag. If you are only using 4" lines, this is the proposed method, as you won't inclrease volume, however your static pressure will be double.

Parallel means both blower inlets are connected to a common suction manifold and the outlets again into a manifold wich goes to the dust bag of filter. You will double the volume, but your static pressure will be too low to handle 18' of 4" line, killing the system. If you were using 6" lines, this would work.

Kind of the same concept as electricity, if you connect two 12V batteries in series, you have a higher potential difference (pressure) or Voltage, being 24V. If you connect them in parallel, you will have more capacity for current, (flow volume), but they will still only deliver 12V.

Hope that helps.


----------



## tvman44 (Dec 8, 2011)

I think the pusher will hurt more than help and you would have dust coming out at the tool. Maybe parallel the 2 to a Thien type separator then your piping system..


----------



## rrbrown (Feb 15, 2009)

If you use larger main line like 6 inch. you can use a 6x4x4 wye to connect the ywo blowers to the main line. Both blowers with it's own filter/bag setup you will effectively double the possible air movement. Reduce down to the 4" port at each tool and you will have a lot more velocity at the tool.

it would be similar to this.



WillemJM said:


> Parallel means both blower inlets are connected to a common suction manifold and the outlets again into a manifold wich goes to the dust bag of filter. You will double the volume, but your static pressure will be too low to handle 18' of 4" line, killing the system. If you were using 6" lines, this would work.


However by WilemJm saying connect both blowers to same filter/bag you stall out the system at the bag. By using two separate bags the restriction should be gone.

Warning this is only theory and the use of two blowers and bags require a lot of floor space.


----------



## WillemJM (Aug 18, 2011)

rrbrown said:


> If you use larger main line like 6 inch. you can use a 6x4x4 wye to connect the ywo blowers to the main line. Both blowers with it's own filter/bag setup you will effectively double the possible air movement. Reduce down to the 4" port at each tool and you will have a lot more velocity at the tool.
> 
> it would be similar to this.
> 
> ...


Correct, the dust bag needs to be sized for the volume, or just use the bag on each blower if the space and equipment is already there, if connecting in parallel.


----------



## NVCowboy (May 24, 2012)

Thanks for all the help. I hooked everything up today, with only the Delta on the back end, and it performs clear down to the floor sweep on the far end of the system (only thing hooked up at this point). I do give credit to the fact that there is no vertical climb to overcome in the system, as it is only a floor sweep and a blastgate off teh floor. Some more pipe supports and waiting a month to afford the flex tubing, and away I go. Again, thanks. I was afraid the 1Hp suction would not be enough. Will post pics when I get a chance. 

Later, and stay safe
Bill


----------

