The essential system types of differential pressure systems are:
And the combination:
Differential pressure systems can be used in buildings, staircases and landings, anterooms, corridors and fire brigade elevator shafts to create a security zone.
Like this the objective to support self-rescue and fire-fighting can be fulfilled.
Physically simplified, differential pressure systems realize an appropriate overpressure at the door top edge between the area on fire and the pressure area (staircase and landing), which prevents or delays the smoke entry from the area on fire.
A defined exhaust flow from the area on fire into the atmosphere secures flow-energy in the open door cross section which also has to be proved on the construction site during construction approval.
Only the compliance with the maximum permitted door-opening-force of 100N decides about the accurate level of overpressure in the staircase.