Human re-inhalation ratio under typical conditions

Inhaled air quality is directly related to occupants’ health and of life. In this study, a numerical breathing thermal manikin was employed, who breathed following sinusoidal function, with 10 cycles per minute. Each cycle composed three phases: 2.5 s inhalation, exhalation, 1 pause. The influence pulmonary ventilation rate, mode period on the re-inhalation ratio were studied by computational fluid dynamics (CFD) technology in combination species transport model. It found that increasing rate led lower ratio. largest value 0.91%, when exhaled through mouth inhaled nose. up 23.9 % pause than without When increased from 6 L/min 8 L/min, decreased 0.91% 0.71%. This information would be an important basis for development human microenvironment control technologies, including intelligent, personalized supply devices, local exhaust methods, other advanced airflow technologies.