What would be a modern analogy of this I wonder?
one company that cleans them is called 1-800-CHUTE-ME
there is also a button in the elevator called "taxi". if you push it, it lights a red light on the end of the awning over the sidewalk out front. Back in the day, a taxi could notice it and stop. You see them around NYC but the taxis don't really pay attention to them any more.
there are other ventilation systems that move air all over the building (they bring it in from outside, filter it, condition it, and pump it into hallways (elevator lobbies) up and down the building; it travels under the apartment front doors, and it is sucked out the bathroom vents; it is called "make-up air") These other fans and vent systems also shut down and seal and seal if heat/smoke/fire is detected.
buildings are intricately balanced mechanical engineering systems where all the parts are intertwined