Design Help

[HRees44]

First of all, thanks for everyone putting up all of this information, it is awesome.

I'm setting up my first dust collection system in my one car garage.  I want to keep it all ducted, so I don't have to move it around tool to tool.  I just bought a 2hp Harbor Freight dust collector.

Here is my dilemma.  All of my tools that need major dust collection are along one wall (in order to keep the ducts as short as possible). This is pictured below.  I'm debating on where to locate the dust collector. I have two choices (pictured below).

Choice 1: Put it in the corner, and run ducts all the way the length of the wall and have one side inlet into the seperator in the corner.

Choice 2: Put it in the middle of the wall.  This creates the shortest possible ducting to all of the tools, but introduces the problem of ducting and airflow coming from opposite directions.  I prefer this method, but am having troubles making the inlets have as little resistance as possible. I want to have side inlets, to git rid of the 2 90 degree bends a lid inlet has.  BUT, I have the inlets coming from opposite directions, so I was thinking of setting two baffles on top of one another, one baffle for each inlet (Pictured).  Each baffle would have air flowing in the opposite direction. 

I thought if I put the two inlets on the same baffle/level, that the dust would get hung up on the opposite inlet as it spun around the can, and have a higher likelihood to get sucked up into the outlet.

Let me know what you guys think. Sorry for the crude drawings, but hopefully they get the idea across.

[Vodkaman]

The double baffle idea, very interesting but I cannot see that working. I don't think the double baffle will be necessary. run the two inlets into the same baffle. Another problem is the area of the piping cross section. You are doubling the area and the volume and so halving the sucking power at the tool.

If you have some form of gate system, so that you can shut off the half that you are not using, I think it would work. Better still would be to gate each tool, so you get the maximum suction where you need it and all unused tools are closed off, after all, you can only work on one tool at a time. The danger is with this idea, is if you have all the gates closed when you switch on, you will likely collapse the bin. This can be solved by building in a vacuum relief valve.

I like the central collector idea.

Dave

[HRees44]

Thanks for the response. Yes, I was definitely going to put in several blast gates. One at each tool.

I think I'm leaning towards foregoing the side inlets all together.  It will be awkward to have two inlets, as the 240 degrees that would normally be open for debris to drop down in would have to be reduced.

I think I'm going to just go with a Y inlet into the top, and run each length of hose into the Y, with blast gates on all tools. I will take some pictures of the finished product, hopefully later today. 

Thanks

[Vodkaman]

I can understand you deciding to go with a more traditional and proven system, after all there is a lot of work and cost involved in building these master pieces.

Your theory was sound. The twin inlets would have removed 180 degrees of bends from the system. True, the baffle drop slot would have been an unknown. It is always interesting to read new ideas.

If you gate everything, don't forget about the vacuum collapse problem.

Dave