Dynamic ventilation control modes for elevators: towards healthy built environment

Aerosol transmission of viruses poses a significant threat to public health and socio-economic stability. Elevators, as typical frequently-used enclosed spaces in modern building transportation systems, pose growing aerosol transmission risks. However, previous studies have not adequately optimized elevator ventilation control for intermittent door operations and with fluctuating occupancy patterns. The study emphasizes intelligent control strategies of mechanical ventilation hybrid with natural ventilation utilizing elevator door opening dynamics. It thoroughly examines factors influencing the spread of respiratory infectious diseases and proposes effective solutions. A validated Computational Fluid Dynamics (CFD) model is employed to analyze the spatial-temporal distribution of virus-laden aerosols in elevator cabins. Simulation results demonstrate that elevated ventilation rates may paradoxically increase aerosol dispersion due to enhanced turbulent diffusion, while insufficient ventilation prolongs aerosol residence and exposure time. Specifically, at an airspeed of 0.2 m/s, aerosol particles accumulate significantly, increasing infection risk; whereas at 2.5 m/s, particles are rapidly expelled but dispersed more widely. The study proposes an intelligent variable-speed ventilation strategy ​​based on real-time CO2 concentration levels. Compared to conventional ventilation systems​​, the proposed adaptive system combining optimized ventilation rates with door-opening operations​​ demonstrates a 43.5% improvement in aerosol dilution efficiency ​​while reducing both infection risks and energy consumption​​.The findings provide valuable insights and practical solutions for the intelligent control and optimization of elevator ventilation systems in modern urban environments.