Better than "stovepipe mod" - a tour of my dust collection

[Dan Friedrichs]

I recently finished the drywall and painted my garage/shop, so it was a good time to re-do the dust collection.

I have a crawlspace under my house that is situated only a few feet lower than the garage floor. I have my dust collector (a 2HP, 12" impeller Grizzly) located in this crawlspace, as it significantly reduces the noise from the blower.

I removed the top bag from my dust collector, and replaced it with a plywood disc with 6" hole in the center which connects to a piece of 6" PVC pipe which blows all the exhaust air outside. I installed a Thien baffle in the lower bag of the DC, which does an amazing job of keeping the chips in the bag (there is no visible dust escaping outside). The lower bag is lined with a trash bag, so when it fills I can just tie it up and throw it away.

I replaced the 5" input port on the blower with a plywood disc with 6" input hold cut in it.

Since I exhaust outside, I need to open a door in the garage a crack to allow make-up air back in.

All the above has been working fine for me for some time, but I felt I needed more suction. In my "renovation", I:
-removed two 90* elbows I had in the system
-replaced about 12" of flex duct directly on the input to the DC with PVC pipe
-removed the piece of 5" flex pipe that connects between the blower and the bag, and built a stand to directly connect the blower output to the bag input

Doing the 3 things listed above made a TREMENDOUS increase in suction. I have no way to measure CFM's, but can comfortably say that these improvements resulted in more than 40% increase in airflow. I suspect the piece of 5" flex between blower and bag was a serious restriction.

I have not measured the power draw on the motor, but it does not get uncomfortably hot.

[Art Mulder]

If you get contractor-grade (3mil) trash bags, then you won't need the outer fabric bag. That's what I use on the bottom of my 2HP DC.

Being in the crawlspace... is it hard to check if it's getting full? That could lead to a big mess!

And yet another Thien Baffle user... I'd wager that Phil had no idea what he was getting into when he posted his baffle design. I'm going to have to add one to my system sometime!

[Dan Friedrichs]

Art,
I think I will get the thicker bags next time. I had tried having the blower and bag in the garage, but putting it in the crawlspace easily reduces the noise by a factor of 10. It's the difference between wearing ear protection with just the DC on, to being able to have a conversation while it's on. To me, the inconvenience of having to check it for full-ness and lift a full bag up a few feet is totally worth the noise reduction. Plus, it saves space in my small garage.

[Tri Hoang]

Great job...I agree that getting rid of the 5" hose section between the blower and the bag. I like the push configuration also. Just make sure you dont pick up large stuffs (plastic bags, wood chunks).

[Dave Gaul]

Dan this looks great!

I am hoping to do something similiar soon...

On the exhaust that you ran, you used a 6" pvc run to outside... does anyone think that flow would be improved by using a larger diameter exhaust? Maybe a 8" exhaust?

[Alan Lightstone]

Is it still a 5" connection between the blower and the baffle but just a direct connection, or did you increase the diameter of the opening?

[Dan Friedrichs]

Alan, it is still 5" (I considered converting to 6", but that would have required making a 6" hole in the bag ring, which sounded hard).

[Terry Hatfield]

Great job Dan. The system looks super. I would suggest that you should check the currrent draw on the motor just to be safe. Increasing the airflow will certainly increase the strain on the motor. A simple clamp on style amp meter will answer the question and either give you some added peace of mind or...

Terry

[Todd Franks]

Great job Dan. The system looks super. I would suggest that you should check the currrent draw on the motor just to be safe. Increasing the airflow will certainly increase the strain on the motor. A simple clamp on style amp meter will answer the question and either give you some added peace of mind or...

Terry

My experience with the 2 dust collectors I've owned in Colorado @ 5000ft is that is damn near impossible to get the motors to draw anywhere near FLA even with inlets and outlets enlarged and no ductwork or filters at all.

I still agree with Terry's sentiment however in that it doesn't hurt to check. I also agree that your setup looks great.