That's a nice setup Johnny, errr... Steve-O.
Thank you for the video. It gives us rookies a very good idea on how to set things up.
I noticed in your video you mentioned that you hope the negative air machines will capture whatever comes inside when the door is opened. My thinking is, would it be a better idea to perhaps pick a corner, put the door on one side of that corner, and the negative air machines on the other side of that corner? The door and the negative air machines will effectively face each other at a 90 degree angle. The door can be installed so that the part that opens faces the negative air machines, which will immediately capture anything as soon as the door opens and the air rushes in.
Hope my description makes some sense.