CFD ANALYSIS OF AIRFLOW CHARACTERISTICS IN OFFICE ROOM WITH TASK AIR-CONDITIONING AND NATURAL VENTILATION

The performance of indoor airflow for the office room with the hybrid air-conditioning system has beeninvestigated by means of CFD analysis. The hybrid air-conditioning system is composed of under floorair supply outlets for task zone and the natural ventilation openings for ambient zone. The measureddata (Kotani et al. 2006) at the office room in existence was used as the boundary condition of the flowrate of each natural ventilation opening and task flow outlets for CFD. To investigate the influence oflocation of the natural ventilation opening, two models with different location of openings for naturalventilation were made; one is the case with openings for natural ventilation under the ceiling(ceiling-model; Lim et al. 2007) and the other is the case with openings for natural ventilation near thewindow side (counter-model). It was made clear that the ceiling-model can supply the fresh air morewidely to the occupancy zone than counter-model. Moreover, CFD analysis using ceiling-model wasconducted to investigate the influence of the outdoor air condition (wind direction, wind velocity andoutdoor temperature). As the results, the distribution of fresh air under the north wind is more uniformthan that of the west wind. Under the west wind, SVE4 of natural ventilation openings is highest in thewest-side zone.