Comparison of Push-Pull Air Curtain to Overhead Downdraft Systems on Aerosol Containment and Distribution in Controlled Environments

Abstract

This dissertation examines the sustained problem of airborne aerosols generated during clinical and dental procedures and assesses particle engineering strategies to mitigate exposure of Healthcare workers and patients are exposed to these aerosols. The first study emphasizes the size distribution. airborne persistence, and stopping distances of particles generated by common aerosol-producing procedures in the medical field, demonstrating that fine particles (<5 µm) remain suspended long enough to avoid basic droplet-based controls. As a transition, the second study compares three air curtain configurations, i.e., Push, Pull, and Push-Pull, in a purpose-built dual-compartment chamber and demonstrates that a well-tuned Push-Pull arrangement consistently delivers the best containment (≈95% under optimized conditions), maintains performance when modest Obstructions are introduced, which outperform single-stream designs. The third study translates the chamber results to realistic clinical rooms by applying Reynolds and Euler number as a dimensionless parameter for scaling and regression-based predictions. The scaled models indicate that the push-pull system can achieve comparable containment in full-scale settings, when properly calibrated and integrated with existing ventilation. These studies show that combining targeted engineering controls with routine Ventilation and personal protective equipment reduce aerosol escape from procedural zones. The studies also provide partial parameters (jet velocity, nozzle geometry, and pressure balance) to guide clinical implementation