Optimized performance of displacement ventilation aided with chair fans for comfort and indoor air quality -

Abstract

This study optimizes the performance of displacement ventilation (DV) system aided with chair fans (CF) for providing acceptable thermal comfort and indoor air quality (IAQ) in office space. A 3-D computational fluid dynamics (CFD) model is used to predict the airflow, temperature, and CO2 concentrations fields. The (CFD) model coupled with a bio-heat model was used to predict the airflow, temperature, and CO2 concentrations fields as well as the occupant segmental skin temperatures for local and overall thermal sensation and comfort evaluation. Occupant. The CFD model results were validated experimentally in a DV conditioned space using a thermal manikin seated on a chair equipped with fans Simulations were performed using the validated CFD model to determine the fans optimal height from the floor. For a source located at 1.0 m from the floor, it is recommended to place the fans at 30.9 cm above the floor at fans total flow rate of 12 L-s while for a source located at 0.3 m from the floor, the optimal height for fans is at 30.1 cm above the floor at fans total flow rate of 12 L-s. Compared to stand alone system, energy savings were 20.6percent and 11.6percent for fans’ optimal heights of the sources placed at 1.0 m and 0.3 m, respectively.