The Influence of Evenly Distributed Ceiling Mounted Personalized Ventilation Devices on the Indoor Environment

The advantage of conventional personalized ventilation (PV) is to considerably improve the fresh air percentage near PV air terminal devices (ATDs). However, the distribution of the fresh air percentage is very uneven in the field. Occupants are confined to their working zones in order to obtain good inhaled air quality. Ceiling mounted PV can overcome the disadvantages of conventional PV, although the fresh air percentage is lower than that of conventional PV near working zones. A typical office workplace consisting of either ceiling mounted PV ATDs or conventional PV ATDs and ambient air supply diffusers is simulated, based on an indoor air quality chamber at the National University of Singapore. Based on the numerical results, it is concluded that ceiling mounted PV can improve inhaled air quality for both seated occupants and moving occupants over a longer occupied area although conventional PV can improve inhaled air quality much better in the immediate breathing zones at the work stations.