2022/02/01 by Kazuki Kuga, Pawel Wargocki, Kazuhide Ito
Engineering · Environmental Science · Medicine · #Building Energy and Comfort Optimization #Infection Control and Ventilation #Wind and Air Flow Studies
paper · doi:10.1111/ina.13003
openalex publication_date 2022/02/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/01
The breathing zone of an individual indoors is usually defined as a finite region steadily formed in front of a face. Assuming the steady formation of the breathing zone, we propose a procedure for quantitatively identifying a breathing zone formed in front of a human face in the transient condition. This assumption is reasonable considering that the ventilation time scale of human respiration is sufficiently short compared to the ventilation time scale of a room. We used steady-state computational fluid dynamics (CFD) and a computationally simulated person (CSP). We present the probabilistic size of the breathing zone for various postures and breathing conditions. By analyzing unsteady inhalation and exhalation airflow characteristics via a CSP with a respiratory system, we also estimated the direct re-inhalation rate of the exhaled air. The results can be used for developing methods to control the long-term and low-contaminant concentration exposures.