Computational study of personal ventilation jets using a sweating, breathing, thermal manikin

In this paper we use an experimentally validated computational fluid dynamics (CFD) model that includes a personal ventilation (PV) system, seated thermal manikin and floor diffuser to assess the effect of moisture and breathing on PV. The PV systems include a single round jet and a novel low-mixing Co-flow nozzle that direct fresh air toward the breathing zone (BZ). First, we compare the air quality in the BZ of a thermal manikin with a skin wettedness of 0%, 6% and 50% for both PV systems. We also compare the air quality in the BZ for a case with no breathing, steady inhalation of 6 lpm and unsteady sinusoidal and realistic breathing of 6 lpm for both PV systems. The results show that the Co-flow nozzle is more robust than the single jet, however, both moisture or breathing modeling method have little effect on the BZ air quality when using a PV system that directs air towards the face.