Fire dampers should be installed in the air supply line. Fire dampers and regulators are usually installed together and both must be normally open. In case of fire, the fire damper will automatically close. In addition, the fire damper can also regulate the flow. Fire protection and smoke extraction are very important in building design, so you need a fire protection design for each zone, but if you want to fundamentally solve the fire hazard, do it only with smoke prevention. I can not do it. Therefore, care must be taken in zoning the shaft when designing.