Seat-integrated localized ventilation for exposure reduction to air pollutants in indoor environments

A novel ventilation method for minimizing the spread of bioeffluent contaminants generated from sedentary people indoors was developed and studied. The concept of the method consists of a ventilated cushion which is able to suck the human bioeffluents at the area of the body where they are mainly generated before they disperse around a room. The polluted near the body air is exhausted into the cushion and it is removed from the room by a separate exhaust system. The performance of the method was studied in series of experiments. Full-scale room and a dressed thermal manikin sitting in front of a desk were used to simulate one person office. The chair on which the thermal manikin was sitting had the ventilated cushion (VC). Tracer gases, carbon dioxide (CO₂) and nitrous oxide (N2_O), were used to simulate bioeffluents emitted by the manikin’s armpits and groin region respectively. The experiments were conducted at 26°C room air temperature. The performance of the VC in conjunction with mixing total-volume background ventilation at 1 air change per hour (ACH) was compared with that of mixing background ventilation alone operating at 1, 1.5, 3 and 6 ACH. Experiments at exhaust airflow rate from the cushion at 1.5, 3 and 5 L/s were performed. The pollution removal efficiency was assessed by measuring the pollution concentration in the breathing zone of the manikin and at several other locations in the room bulk air. Exhausting air through the VC decreased the concentration of the tracer gases at the breathing zone and in the room. The higher the exhaust flowrate, the more the concentration was decreased.