The only thing I've even got a clue about when it comes to air pressures and space differences is negative air pressure used in some hospital environments. A room with a lower pressure than its surroundings will cause air to flow into the room from the outside whenever one of the portals is opened. So, all the airborne contagions stay in the room, rather than being sucked out to be shared, all friendly-like, with the rest of the hospital.

I know this isn't what you're looking for, but maybe negative air pressure would be a place to start poking?