Inhaled air quality with desk incorporated personalized ventilation (PV): parametric study

A workstation consisting of a desk with installed personalized ventilation (PV) and a dressed breathing thermal manikin simulating seated occupant was set in a full-scale test room. The room was conditioned by overhead ventilation at 26 oC. The PV consisted of two confluent jets incorporated along the front edge of the desk and supplying clean personalized air vertically towards the face of the manikin. The inner jet (closest to the body) delivered always clean outdoor air and the outer jet provided room air mixed with tracer gas (R134a) at the same flow rate as the inner jet. The breathing thermal manikin was seated with abdomen pressed against the table edge. The amount of clean air inhaled by the manikin was measured under numerous experiments studying different combinations of personalized airflow rates (isothermal) - 2, 4, 6, 8 and 10 L/s, widths of the two jets - 0.03 and 0.06 m, posture of the manikin - seated with the abdomen pressed against the table edge, moved backwards from or leaned over the table. The best performance was achieved with the 0.06 m openings: 85% of PV air was inhaled by the occupant at 10 L/s. The portion of clean PV air inhaled by the manikin was 80% when it was bent over the table, 76% when the manikin was seated upright and 45% when the manikin was moved backwards.