DRAFT SENSATION STUDY IN A SPACE SERVED BY DISPLACEMENT VENTILATION SYSTEM IN THE TROPICS

摘要

This paper presents a draft perception study of Displacement Ventilation (DV) system in a Field Environmental Chamber (FEC) with tropically acclimatized subjects. A total of 60 subjects, 30 males and 30 females, were exposed to 3 vertical air temperature gradients, 1, 3 & 5 K/m, between 0.1 and 1.1 rn heights and 3 room air temperatures, 20, 23 & 26°C at 0.6 m height for a 3-hour period. Air velocity near the subjects was maintained at below 0.2 m/s. Relative Humidity (RH) at 0.6 m height and fresh air provision was fixed at 50% and 10 l/s/p respectively. It was found that in the space served by DV system, draft perception was insignificantly affected by temperature gradient. Room air temperature had greater impact on percentage dissatisfied due to air movement than temperature gradient. Cold sensation would add draft risk and warm sensation would increase percentage dissatisfied due to insufficient air movement.