Stack effect is defined as airflow in shafts induced by indoor-to-outdoor temperature differences that lead to density differences and flow. Due to variable pressures and temperatures between floors in a multi-story building, stack effect can be quite troublesome in the event of a fire emergency.
Elevator shafts can often act like chimneys in multi-story buildings as they enable large amounts of air to move from floor to floor. Because of this, elevator shafts can easily transport smoke throughout a building in the case of a fire. Therefore, installing a fire and smoke containment system within an elevator shaft is crucial for building fire safety.
For most buildings, fire doors are typically located around stairwells and elevator shafts as to limit the ability for smoke to leak from floor to floor. However, fire and smoke containment systems can be a little more complex for buildings in the healthcare industry such as hospitals.