Center for the Built Environment

A personal environmental conditioning (PEC) system using air-jet cooling was evaluated for its thermal comfort, perceived air quality (PAQ), and eye comfort. The room surroundings and the air jets were both fixed at 28ºC and 50% RH. Two 4W fans directed room air toward the occupant’s breathing zone from opposite sides. The premise was that facial air movement would both cool the occupant and disrupt potential PAQ in the body plume. Eighteen subjects participated in 90 3.5-hour tests. Comfort was assessed both at the workstation and during periodic breaks away from it. Comfort persisted throughout ten-minute standing/conversation breaks. After 15-minute step-climbing breaks had ensured discomfort, comfort resumed immediately upon the occupants’ return. The influence of body plume on PAQ was examined using a plume-deflecting collar and a menthol scent applied at the waist. The collar significantly reduced the scent intensity, and the PEC air jets had the same effect.