Dust Collector Filter Configuration Help

[James Staley]

Hello all. First time poster here.

A little over a year ago I purchased a Donaldson Torit 5HP dust collector at auction for $500. I cleaned it up, repainted it, and have it reassembled in my shop. I’m now in the process of trying to determine the best filter configuration for my given situation. I’ve come up with three potential options, which are outlined below. I’m hoping other that have installed filters and/or plenum boxes might weigh in as to the best of these options.

Option 1 uses two 14X36 MERV 15 filters from Penn State Industries. Each filter provides 350 s.f. of filter media (700 s.f. total). The plenum box would be connected to the outlet of the cyclone, with the filters connecting to the bottom side of the plenum box. Each filter would have a fine dust cleanout bucket attached to the bottom. As I see it, the big drawback to this configuration is that the airflow will take a sharp 90 degree turn from the outlet to the filters. In addition, in this configuration the filters cover up part of the window. Not a huge deal, but still a consideration.

Option 2 utilizes three 12X26 MERV 15 Donaldson Torit filters purchased from Ebay. Each filter is 256 s.f., for a total of 768 s.f. In this configuration, the filters would be housed inside the plenum box, and airflow would be from the outside of the filter in. This configuration has the benefit of being the most inexpensive, most out of the way, and contains the most filter area. However, when it comes time for filter cleaning the box needs to be opened to remove the filters. As fine dust would be accumulated on the outside of the filters, I’m concerned that this configuration would result in a huge fine dust mess being created when the filters are removed. This would obviously be counterproductive to having a dust collector in the first place. In addition, the plenum box construction would be a bit more complicated for this configuration.

Option 3 again uses two of the 14X36 Penn State filters. However, they would be in a stacked configuration with a fine dust cleanout bucket at the bottom of the stack. As I store my wood pellets adjacent to my dust collector, the plenum box would need to be longer to reach a location suitable for the filter stack. Just to the right of the electrical panel in the photos is the building corner, with the man door being on the adjoining wall. In this configuration, the door would open into the filters. My main concern here would be having the filters damaged and/or dented from the in-swinging door. I would always add a door stop to get around this.

I have considered venting to the outside. However, my shop is in northern lower Michigan and is heated with a pellet stove. Venting to the outside would likely cause a backdraft through the pellet stove vent, which would obviously be less than desirable. As such, venting to the outside isn’t an option.

I’m interested in hearing from others that have installed filters/plenum boxes. Any feedback would be appreciated.

Dust Collector Filter Setup - Option 1.jpgDust Collector Filter Setup - Option 2.jpgDust Collector Filter Setup - Option 3.jpg

[Aaron Inami]

I think you are kind of splitting hairs here. I will say that, based on your images, the second scenario with the three 12x26 filters is not going to work because you are only using half of the filter area for output. The exhaust from the dust collector needs to be fed into the inside of the filter through the hole at top so that you can use the entire filter area.

If it were me, I would choose option 3 with the two Penn State filters stacked vertically. Instead of building that long plenum, I would use one or two duct silencers in place of that (such as Fantech LD8 or LD10, depending on what the output area is). These will significantly reduce the "screaming" from the impeller noise directly at the output. These are low cost solutions from Supply House:
https://www.supplyhouse.com/Fantech-...cer-for-8-Duct
https://www.supplyhouse.com/Fantech-...er-for-10-Duct

Be aware of how much space you have. The length specifications from Fantech do not include the flanges at the ends. The LD8 is published as 23-5/8" long, but it's really like about 29" when you take into account the duct flange extentions. The LD10 is published at 35-1/2", but it's probably more like 40-41".

Another idea - How much room do you have in that corner. I would consider moving the filters closer into the corner and then surrounding them with walls of Rockwool Comfortboard 80 to absorb all the low frequency rumble that comes out of the filters at this point. Both of these things will reduce the overall noise generated by the dust collector. The filters don't necessarily have to be right next to the dust collector output.

You can browse through this thread to see how me and Kyle did our dust collection setups:
https://sawmillcreek.org/showthread....ollector-build

Hope this helps.

[Aaron Inami]

Oh, and try to use a long radius elbow when connecting to the filter stack instead of a flat wall plenum. It will help with the flow/resistance of air.

[Greg Parrish]

I agree with Aaron and would choose either option 1 or 3. I like the compactness of option 1, but option 3 may allow for better air flow and sound reduction. That said, the Oneida and Clearvue options typically hang a long or double stack filter right off the side. I might see if an Oneida, Grizzly, Clearvue, etc., part fit the square flange on the side of yours. If so, you could easily bolt it on and transition right to a tall or stacked filter.

[Aaron Inami]

I just re-read your design and was mistaken. You said this

"the filters would be housed inside the plenum box, and airflow would be from the outside of the filter in"

So the plenum box would be much larger and only have holes on the top and bottom for the "exhaust". This would work, but would not give you any sound reduction features.

By using 10" hard duct in scenario #3, you won't have any issue with air restriction. The benefit of using 3 filters in parallel on option #2 would not really give you anything.

[Bill Dufour]

I did not know they made a cyclone type collector. All Torits I see for sale are in a box like a refrigerator.
Bill D

[James Staley]

Aaron & Greg - thanks so much for your input. I'll definitely take a closer look at doing the stacked configuration.

Bill - yep, Torit makes cyclones in all sorts of shapes and sizes. As they are industrial collectors, you don't often see them used much in home shops due to height and their 3 phase motors. I actually had to do a "bump up" in the shop ceiling for the motor despite having 10' side walls. I was able to get around the 3 phase motor issue with a VFD I purchased off of Amazon.

[Kevin Jenness]

If you can store your pellets somewhere else and use that space for a bank of tube filters you will avoid the inevitable and discouraging task of cleaning those cartridges. My feeling is that pleated cartridges should only be used if space saving is paramount.