Human response to five designs of personalized ventilation

Human response to five different air terminal devices (ATDs) for a personalized ventilation system (PVS) was studied in an experimental office under well-defined conditions. A group of 30 human subjects assessed air quality and rated their thermal comfort and perception of draft. Two temperature levels, 23 degrees C and 26 degrees C, and two background levels of air quality in the office, high and low, were studied during the experiments. Under all conditions the personalized ventilation system provided outdoor air at a temperature of 20 degrees C. All PVSs allowed for individual control of the airflow rate as well as for adjustments of the supply air direction. Results showed that all ATDs studied significantly improved perceived air quality at the workstation. The greatest improvement was obtained when the pollution level and the temperature in the office were high. The thermal environment created with all systems was assessed as acceptable. Subjects were able to improve thermal comfort with all ATDs studied. The subjects identified which of the tested ATDs they preferred.