Fire ventilation cut-off dampers, unlike fire dampers, in the waiting position, that is, during the normal operation of the facility – remain closed. If a fire is detected in a given fire zone, a command is sent from the CSP to open the fire ventilation cut-off dampers in this zone. By opening the flaps in the danger zone, they move to the safety position. Fire ventilation cut-off dampers remain closed in other zones, thus protecting them against gases and fumes, which are removed with smoke extraction ducts. Thus, shut-off fire ventilation dampers are closed, outside the zone where the fire was detected, they are also in the safety position during a fire. The exception is the transfer flap between the vestibule and the evacuation corridor, which remains open in the waiting position. Transition to the safety position – closing the transfer flap, occurs when the thermal release is triggered, which in practice is only in the case of, when the firefighting action is unsuccessful, and the fire develops to that extent, that at the height of the damper thermal release, the temperature activates it, tj. usually when it reaches 72 ° C. Closing the transfer hatch means the end of the effective protection of the evacuation corridor against smoke.