Distribution of contaminants in the occupied zone of a room served by a novel enhanced displacement ventilation system

The aim of this study is to examine contaminantdistribution in the occupied zone of a room servedby a novel enhanced displacement ventilationsystem which brings cooler air near the floorupward around human body via 4 fans mounted ateach corner of a chair. An office with twoworkstations was simulated in a full-scale testroom. The discharge angle of the flow from thefans was varied to be 0, 30, and 60" from thehorizontal plane. Two breathing thennal manikinswere used to simulate the occ~~pantwsi th oneserved as a polluting manikin and the other one asan exposed manikin. The exhaled air of thepolluting manikin was marked by a tracer gasFreon, and it was sampled at the mouth of theexposed manikin to study the cross effect and theimpact of the flow generated by the fans on theexposure. Freon was also sampled at 6 differentheights in the occupied zone at 2 locations in thechamber as well as in the supply and exhaustunits. The results show an insignificant impact ofthe fan angle on the inhaled air quality. It is alsofound that the exposure to the exhaled air of thepolluting manikin was increased when either thepolluting manikin or the exposed manikin usedthe fans. And the exposed manikin is prone tomore polluted air transported from the pollutingmanikin when the exposed manikin uses the fans.The use of the fans increased the contaminantconcentration in the occupied zone.