Occupant-distribution-based CO

Demand-controlled ventilation (DCV) in office buildings relies on a single zone-level carbon dioxide (CO2) sensor to regulate outdoor air supply in response to zone occupancy inferred from CO2 levels. Although effective for reducing ventilation energy relative to constant-volume systems, this strategy assumes spatially uniform occupancy and CO2 distribution, which can limit both indoor air quality (IAQ) and operational flexibility. To address this gap, this study proposes a method that combines CO2 sensing with seat-level occupancy detection to allocate ventilation air more intelligently across the breathing zones of occupants. In the experimental setup, CO2 sensors were installed in the breathing zone of each defined zone within a typical office layout and above the multi-user activity table to capture spatial variations in occupant-generated CO2 concentration. Seat-level occupancy and CO2 measurements were applied to simulate the ventilation rates required for occupied areas without implementing active control. System performance was evaluated by analyzing the modeled airflow response and IAQ maintenance under time-varying occupancy conditions. The results demonstrate that incorporating seat-level occupancy with CO2 sensing can contribute to improving the responsiveness and efficiency of the building ventilation system.