My new shop will have a dust collector in the basement with the ductwork below the main floor. I have to contend with the HVAC ductwork.

Attachment 411866

The basement height is 10' 3" to the bottom of the floor joist so there is height for the main dust collection trunk to pass under the trunk HVAC duct. As I indicated in my construction thread, the main dust generators are clustered in the center of the floor. Tools like the router table, drill press, band saw and stationary sanders are along the perimeter wall. The lathe is in a far corner.

I am struggling with meeting all the criteria for good dust collection design. I have a Oneida Portable 2 hp Dust Gorilla that I bought several years ago. The specific model has been discontinued. This model is somewhat small for stationary unit servicing this size shop. It was fine as a portable unit connected to one tool at a time with a 10' of 6" flex. The longest duct lengths in this shop may be too much for it to provide adequate flow.

Here are some constraints and design considerations that I need to work with. The basement is also a garage so I will have to have fire proof sheetrock on the ceiling per code. I am planning on just dropping the whole ceiling below the HVAC and DC ductwork resulting in about an 8 ft finished ceiling height. In addition to the HVAC ductwork. I also have a roll-up garage door that would preclude having DC duct going under the HVAC in that area. The hand tool area is above the garage door tracks so I may just use a shop vac for the hand sanders and such.

I know that the duct into the collector inlet port should have a straight run entering (~10 pipe diameters or about 5 ft for 6" duct) so that the air flow is perpendicular to the impeller for good pumping efficiency. So that means I have to run the main pipe 5' horizontally then turn up to get to floor joist height. I plan a centrally located closet in the basement to enclose the DC and this horizontal section of inlet pipe. The closet would straddle the main trunk for the HVAC. I can route laterals in either direction inside the closet. The closet will have a return air grate through the floor above so the exhaust from the DC returns to the main level. The closet will be about 3' by 6' inside dimensions. I will put my air compressor in this same room. The lateral runs will exit the closet above the dropped ceiling.

That first vertical section will come straight up to serve the table saw and planer. Tees below floor level from that vertical will go laterally to the tools on either perimeter (I need to do the flow calculations to see if the air flow is adequate with the current tool arrangement). I will just have one tool running at a time so all main lines will be 6". Wyes going to individual tools will be a short section of 4" spiral duct through the floor to a blast gate and then flex duct to the tool. I think will need less volume flow in the main lines because all my vertical ducts are down flow. The main goal of the duct layout is short to reduce both cost and flow loss. I shall have to do some engineering.

Does anyone have experience with Oneida-Air duct design service?