Environmental parameters distribution and energy saving analysis with personalized ventilation system

The distribution of environment parameters both at working and ambient area was studied with personalized ventilation (PV) using objective measurement. We performed this experiment in an environment controlled chamber. Subjects were exposed to local airflow towards the face at three air supply volume (25, 15, 10L/s), at ambient temperature of 28 degrees C with PV air temperature of 18, 20, 23 degrees C and at arnbient temperature of 20 degrees C with PV temperature of 26, 30 degrees C. Air temperature and velocity at the workplace were collected at five heights (0.11, 0.50, 0.68, 1.01, 1.21m) corresponding to the altitude of ankle, lap, abdomen, neck and head. The results revealed that air velocity distribution at the workplace closely lay on PV but the temperature distribution was obviously influenced not only by PV but also by mixing ventilation. High velocity airflow was gained in front of face and chest region. Face and chest air velocity values increased clearly when PV supplied more air, however air velocity behind of human body changed little as PV air supply increasing. It was found that transient duration both of air velocity and temperature at the workstation would last more than 10min after turning on PV. The potential of energy saving was also estimated by comparing with traditional mixing ventilation system for a typical office building in Dalian, China.