Comparison of gaseous contaminant diffusion under stratum ventilation and under displacement ventilation

Abstract The gaseous contaminant diffusion under stratum ventilation is investigated by numerical method which is validated by experiments carried out. The concentration of gaseous contaminants along the supply air jet is found to be lower than the other parts of the room. Compared with displacement ventilation, the formaldehyde concentration in breathing zone is lower when a contaminant source locates close to the occupant. The concentration is at the same level when the contaminant source locates up-steam to the occupant. The concentration in the occupied zone (