Smoke removal in shafts

Also called shaft ventilation:

The national building code mandates that hoistways are to be equipped with a smoke removal system - that leads the smoke to the exterior - at the highest point of the shaftway, to stop the smoke from invading the neighbouring levels.

The smoke remover has to be placed in an area where its function can not be impaired by the wind. The smoke removal system also multi-tasks as a ventilation system that also constantly supplies the car with fresh air.