I've never used backdraft dampers before, never even seen one in person.
I have a 15'w x 26'l room that I plan to have an 1200cfm exhaust on one end just to vent the room during lights off. On the other end I plan to have a 12" vent with a backdraft damper. Now in theory, if the room is truely sealed tight this 12" inline fan on the other end of the room should open up this damper right?
I would think that its a matter of Differential Pressure. I am seeing Fabric BDD that are activated by a pressure gradient of 1.5" Water Column. That room volume, assuming 8" ceiling, you would be generating free air flow of 23 room air changes per hour. If its sealed right I would think that you could generate 1.5" water column. It would be simple experiment to determine if you could generate that type of pressure differential.