Elevator shafts need ventilation for the same reason they require protection from smoke, usually by dedicated lobbies. Once the smoke enters the hoistway, it can move throughout the entire building.

How are elevators ventilated?

Elevator hoistway ventilation

A car ventilation system operates through air intake slots at the car floor level where air is drawn from the hoistway and discharged at the top of the car through a 12-in. diameter exhaust fan that discharges air back into the hoistway.

Are elevator shafts safe?

If you are involved in service or construction of elevators; yes, they are safe -or, at least they are supposed to be. ... Maintenance and construction personnel working in or near elevator shafts are most often killed as a result of improper or inadequate fall protection.