I’m gloriously pleased with my recently completed shop dust collection system. Which has absolutely nothing to do with the fact that I think I’m going to redo it.
You may recall from back in March, I did a major installation of ductwork for my shop’s dust collection system. My worry at the time was that the only place I could put the collector was in a corner, necessitating a long duct run. In spite of that, the collection efficiency is top notch for all the tools along the duct run. All except the tool at the end of the line: my table saw. Now, it still does a fantastic job – light years ahead of what I had before – but the efficiency could be better.
I can’t move the tools, nor can the ducting take a more direct path to the saw in the center of the room. However, if I redo the longest section of the run I can make a huge improvement. See, I have a built-in series of benchtop cabinets along one wall, and to get the ducting around this I have to angle the ducting up from near the floor (where the collector’s intake is) to above the cabinets. Although this makes connections convenient for the benchtop tools on those cabinets, the ducting must then come back down to near floor level to get to tools farther down the run. The distance up one side of the cabinets and down the other adds about 5’ to the total run. That’s not too bad, but combined with all the added turns detouring the cabinets the CFM drops by the time it gets to the table saw. Not a huge amount, but enough to tell the difference.
To solve this, I’ve decided to reroute the duct right through those cabinets. This will take some work; I’ll need to cut four 4" holes through the outside walls and inner dividers in that cabinet, then slide the pipe in. I’ll also need to shorten a drawer in one section and a shelf in another, but that's not really a big deal. And cutting holes in the benchtop to run 2-1/2" hose up from underneath to my benchtop tools isn't that big a deal either.
All this would shorten the run by 5’ and eliminate every one of those CFM-reducing bends. As a bonus, I'd get that wall back where the duct is attached now, allowing me to slide those benchtop tools closer to the wall. Further, I’ll be able to lower my lathe/chisel rack, which is a bit too high to account for the duct.
The work involved isn’t difficult, but it will be time consuming. I could have saved a lot of time and effort if I’d have thought it through more completely when I originally did it.