Determining velocity, temperature and occupancy comfort within a 3-D room

Abstract

A computer program for simulating 3-D room ventilation problems is described and employed to predict themean air temperatures and velocities for a number of realistic supply air inlet and outlet locations. The program, TEACH-3D, solves the steady state conservation equations of mass, momentum and thermal energy using a finite difference scheme,m based on the control volume approach. Due to the nature of turbulence, encountered in this research, the K- & turbulence model was selected to transform the open form of the governing conservation equations to closed form. The SIMPLE scheme was employed in the numerical code to handle the velocity-pressure link. The flow field predicted by the numerical code are supported by experimental measuremens done by others. To decide on the effect the geometrical locations of the inlet and outlet have on comfort, the computed results are translated into PMV indices over the entire occupied zone of the room. The PPD is also employed to render judement on the human thermal comfort response, such that if the PPD is less than 20%, then comfort is claimed to be attained. In addition to varying the inlet and outlet locations, the supply air temperature and velocity has also been varied for a particular arrangement in an attempt to achieve thermal comfort. Out of the four different arrangements of supply and exhaust ports investigated here, the one having the inlet on the floor near the West side wall and the outlet on the ceiling near the East side wall satisfied occupancy thermal comfort. While the arrangement least achieving thermal comfort of the occupants is the one having the inlet on the ceiling near the West wall and the outlet on the East wall adjacent to the floor.