The Synergy of Ventilation System Layouts and Occupant Arrangements on Ventilation Effectiveness: A Case Study in a Shared Office

The effectiveness of mixing ventilation for contaminant removal and maintaining indoor air quality remains an active topic of debate. In shared multi-person spaces, it is common for occupants to experience uneven exposure levels due to variations in system configuration and seating arrangements. Previous studies have primarily considered static occupancy schemes, leaving a gap in understanding how dynamic patterns of use interact with ventilation design. This study investigates the combined effects of system settings and occupancy patterns on ventilation effectiveness (VE), while also exploring whether lower ventilation rates can still sustain acceptable air quality. Validated Computational Fluid Dynamics (CFD) models were developed to simulate multiple scenarios involving three ceiling heights, two inlet and exhaust configurations, and three occupancy patterns. Analysis of air quality at the breathing zone reveals that the spatial arrangement of ventilation inlets and exhausts substantially influences VE, with optimized layouts improved system effectiveness by approximately 20%. Seating arrangement was similarly important, with favorable positioning relative to inlets improving perceived air quality by up to 25%. In addition, modest increases in ceiling height reduced the ventilation rate needed to maintain equivalent air quality, suggesting opportunities for energy savings without compromising occupant health. Overall, this study demonstrates that the interaction between system configuration and occupancy has a stronger impact on ventilation performance. These findings underscore the importance of integrated design strategies that align ventilation layout with occupant distribution to achieve both efficiency and equity in indoor environments.