Exposure Reduction to Human Bio-effluents Using Seat-integrated Localized Ventilation in Quiescent Indoor Environment

Local airflows generated from people such as the natural convection flow may determine the distribution of pollutants indoors. New seat-integrated ventilated method was developed to improve the inhaled air quality of occupants while sitting The method named “Ventilated Cushion” was designed to suck gaseous pollutants (i.e. bio-effluents) emitted from the body of a sedentary person and exhaust them before they entrained in the person’s breathing zone or mix with the surrounding air. Full-scale experiments were performed in a climate chamber. The chamber was ventilated by an upward piston flow through the floor. A sitting person was simulated using a dressed thermal manikin which had a body shape and surface temperature distribution of a real average person under state of thermal comfort. The chair on which the thermal manikin was sitting was equipped with the ventilated cushion (VC). The interaction between the natural convection flow around the human body and the suction from the VC was studied in terms of transport of gaseous pollutants. The experiments were conducted at two room air temperatures. The performance of the VC was assessed by measuring the pollution concentration in the breathing zone of the manikin and at 0.5 m above the head of the manikin. The results showed that the concentration of the pollutants decreased when the VC was in operation. The results from this study showed that the use of the VC provides an efficient method for control of body-emitted gaseous pollutants in order to improve the inhaled air and indoor air quality.