Do you have any kind of dust control system in place yet? Also, what type and size of equipment are you using? Basically, I would try to collect as much of the chips and sawdust coming directly off of the equipment, as I could, and once I had that controled I would look at an air cleaner to help eliminate the fine dust. Let us know what you are doing, and I think you will find there is a lot of help in the forum. There is also an older thread on dust control that has a lot of good information in it. Try to find that one.
I don't think you'll notice a difference no matter how you place it. I have a JDS 750ER and it is actually positioned sideways benind my workbench and it does a phenominal job. I highly recomend this unit if you are looking for one.
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