Center for the Built Environment

The goal of this joint project is to examine the physical performance of a Personal Environmental Control (PEC) or Personal Ventilation (PV) system that uses opposing airstreams in order to control the microclimate around the human head, and its effect on people’s thermal comfort and perceived air quality. Both 4” (10.16 cm) and 2” (5.08 cm) diameter nozzles with respective exit velocity 2.0 m/s and 3.0 m/s (respective Reynolds numbers are 13,000 and 10,000) were studied with particle image velocimetry (PIV), hotwire anemometry and flow visualizations. Parallel human subject tests were conducted to validate their effects on people’s perceptions of thermal comfort and indoor air quality. The radial resultant jets generated from the PEC system are able to penetrate the free convection flow at a manikin’s face, and possess a fluctuation frequency of 2 ~ 4 Hz. The PEC system can improve thermal comfort and perceived air quality, while no dry eye discomfort was detected.