Which of the following is included as a natural ventilation alternative in smoke control systems?

In smoke control systems, natural ventilation alternatives are crucial for effectively managing smoke during a fire event, helping to maintain tenable conditions and facilitate safe egress for occupants.

Balcony doors and vestibule doors, while they may allow for some airflow, are not typically classified as effective natural ventilation alternatives in smoke control systems. Natural ventilation in this context often refers to openings that can facilitate airflow throughout the building, such as windows, skylights, or operable louvered vents that are designed specifically for that purpose. These systems are engineered to create paths for smoke to escape while fresh air enters, enhancing the safety of the occupants.

The inclusion of balcony doors or vestibule doors does not align with the intended function or design characteristics necessary for a robust smoke control strategy. Therefore, they are not categorized as natural ventilation alternatives within smoke control systems, leading to the conclusion that neither option is applicable.