Elevator Shafts and Stack Effect Problems - Charles Nehme

Elevator shafts are often treated as simple architectural necessities-vertical voids that allow people to move between floors. In reality, they behave as powerful aerodynamic channels that can strongly influence a building's internal pressure regime, energy performance, comfort conditions, and even fire and smoke safety. In tall buildings, especially, these shafts become part of an invisible but highly active airflow system driven by the stack effect.

The stack effect is not a new phenomenon, but its impact has become far more critical as buildings grow taller, tighter, and more energy efficient. Ironically, the better we insulate and seal buildings, the more pronounced and sometimes unpredictable these pressure-driven air movements become. Elevator shafts, due to their continuous vertical continuity, often become the dominant pathways for this air movement.

This book was written to bridge a gap that still exists in many engineering discussions: the intersection between elevator system design, building pressure control, and HVAC engineering. While each discipline often works independently, real-world performance issues emerge precisely at their boundaries. Elevator doors that resist opening, uncomfortable drafts in lobbies, uncontrolled infiltration, and smoke migration during fire events are all symptoms of the same underlying physical behavior.

The objective of this book is to make these interactions understandable, predictable, and manageable. It combines building physics, HVAC principles, and practical engineering experience to explain not only what happens, but why it happens-and more importantly, how to mitigate it effectively during design and operation.