Evaluating the effect of air flow pattern from a personalized ventilation system on the body local thermal sensation

The present study aimed to investigate the effects of air inlet location and flow characteristics on the performance of a personalized ventilation system. For this purpose, a near-body personalized ventilation system is numerically simulated in an office room with the presence of a thermal manikin. Three air inlet arrangements (in front of the feet, in front of the abdomen, in front of the face) were modeled, two air temperatures (16 and 20℃) and two air velocities (1 and 2m/s) were assigned to each arrangement. Finally, airflow temperature distribution, velocity distribution, and the overall and local temperature and thermal sensation of different body segments are determined. In some cases, by changing the air inlet placement from the front of the feet to the abdomen and head, the whole-body thermal sensation is cooled by 0.54 and 0.6 units, respectively. In all cases, hands and head felt cooler than the wholebody thermal sensation, which shows that the bareness of a segment has a significant effect on its feeling in personalized ventilation systems. Unlike the foot, the head is an effective local segment for non-uniform cooling purposes in warm conditions, and due to its effect on the whole-body thermal sensation, cooling the head would be an effective way to reduce energy consumption.