Comprehensive numerical assessment of stack effect mitigation in high-rise buildings: impacts of architectural, mechanical, and climatic factors

The stack effect presents a significant challenge in high-rise building design, influencing thermal performance and fire safety. This study employs the airflow modeling software CONTAM to quantitatively assess the stack effect and pressure differentials in a building. Key variables examined include building height, HVAC operation strategies, elevator zoning configurations, regional climatic conditions, and the performance of air sealing interventions. The study further explores the impact of emerging multicar ropeless (MCR) elevator systems. Simulation results demonstrate the strong sensitivity of stack-induced airflow to vertical temperature differentials and total building height. HVAC pressurization strategies and transfer floor zoning significantly influence vertical air migration and energy demand profiles. Air leakage pathways, particularly those near ground-level lobbies, are shown to dominate infiltration patterns, with targeted sealing proving highly effective. Climatic variation across Chinese regions contributes to substantial differences in stack pressure gradients, underlining the need for climate-responsive designs. Preliminary analysis of MCR systems suggests potential advantages through decreased shaft surface area and enhanced air sealing strategies. These findings advocate for an integrated approach to tall building design, encompassing climate-specific strategies, precise elevator zoning, and strategic air barrier implementation to enhance supertall buildings’ energy efficiency and environmental performance.