I've decided that I'd like to put in some air filtration. My shop is 28 x 36 with 11' ceilings, although 1/3 to 1/2 is lumber storage. I'm thinking I would like two units to clean the air before the dust settles. What I'm wondering about is placement. I am concerned about shadows / interferance with the lighting and wondering if there is an optimal height or distance from the ceiling and how important is placement as far as being on centerline on one demension and thirds on the other for best coverage. I'm considering the Powermatic PM1200. But for now would be happy to get the outlets in place so I can be ready to start installing the insulatioin and ceiling. Thanks for any practical experience and advice.