The significance of smoke guard in vertical shafts

Each urban building owns one or more vertical shafts e.g. lifts and escalators to connect all moving lines across all stories to make people move swiftly among all floors for convenience, but a vertical shaft spreads the lethal smoke of a fire to each floor and emergency ladders in the shortest time and claims the lives of those choked by smoke before they manage to escape from the building timely, so there must be smoke and fire rated equipment in all vertical shafts to reduce the casualties in a fire.

stack effect:Chimney effect

The smoke of a fire rises up in a building. Without any blocking matters in the staircases or vents, the smoke will climb up rapidly along the openings, making them as if a chimney filled with a lot of smoke. This is so-called the “stack effect”.