The Presidents Ballroom airwalls contain two doors, one for the A/B airwall and one for the B/C airwall.  It is theoretically possible but extraordinarily time-consuming to swap these doors to other locations in the airwall.  Sections of airwall can be omitted, creating additional doorways.  Airwalls cannot be closed on top of dancefloor.
 
The Presidents Ballroom airwalls contain two doors, one for the A/B airwall and one for the B/C airwall.  It is theoretically possible but extraordinarily time-consuming to swap these doors to other locations in the airwall.  Sections of airwall can be omitted, creating additional doorways.  Airwalls cannot be closed on top of dancefloor.