dust collection run lengths

I’ve got one run off my HF 2 HP that is about 30ft long. I have 4” going to all but the tools at the very end. Those tools are my sanders and they have 2 1/2” ports. It works great for me. I believe the recommendation is to decrease pipe size as you get further away to keep velocity. Try to plan your system such that the tools at the end have smaller ports.

-- Bill M. "People change, walnut doesn't" by Gene.

If you’re only going to have one blast gate open at a time, keep the pipe size as large as you can all the way to the tool. Enlarge the tool ports if at all possible. Having a big header and smaller branches makes sense if you have multiple tools making dust at the same time, but in a home shop situation with only 1 tool being used at a time it doesn’t. Minimize static pressure loss in your ducting and tool ports. Go with 6” duct and 6” Flex if you can. It makes a huge difference.

A good discussion of this is here.

You say you’ve decided to get the HF collector, but you don’t say if you have already or not. If you haven’t, consider something with a larger impeller size than the HF one. A 2HP motor spinning a 10” impeller won’t be close to something with a 12” or 13” impeller. If you’ve already bought it, then disregard this last part.

-- Bob Anderton - Austin, TX - Nova 3000 lathe, Alaskan Mark III mill, Husqavarna Saw

I have a two HP Grizzly dust collector outside my shop in a sound insulated closet I built for it. To keep the length of duct to a minimum I ran it on the floor along the wall. No point in going up to the ceiling and down to each machine. 4” will get the chips but 6” will get more of the fine dust. I have 6” all the way to most of my machines. You will find that the duct system parts costs at least as much as the dust collection will. The sawdust on the floor is not dangerous to your lungs. It is the fine dust in the air that is. I also have a ceiling hung room air cleaner that cleans all the fine dust from air in my 23’x13’ shop in five minutes.

-- "You may have your PHD but I have my GED and my DD 214"