Control of the Free Convective Flow around the Human Body for Enhanced Inhaled Air Quality: Application to a Seat-Incorporated Personalized Ventilation Unit

This paper reports on methods for control of the free convective flow around the human body, with the aim of improving inhaled air quality. The methods were studied with sea-incorporated personalized ventilation (PV)-two PV nozzles placed sideways at the head level of a seated occupant supplied the clean air. Another pair of control nozzles below the P V nozzles, the height of the shoulders, either provided an additional amount of clean PV air or exhausted part of the air from the free convective flow. The effectiveness of the methods for enhancing the quality of the inhaled air was studied in full-scale room experiments. A thermal manikin with a realistic free convective flow was used to resemble an occupant in a state of thermal neutrality at a sedentary activity level. Numerous experiments comprising different combinations of nozzle sizes, supply and exhaust flow rates, and direction of the supplied PV flows and of the control flows, etc., were performed under isothermal conditions at 20 degrees C (68 degrees F) and 26 degrees C (78.8 degrees F). The methods of control proved to be efficient and made it possible to increase the amount of clean air into inhalation at reduced personalized flow rate and to reduce the risk of draft.