Effects Of a Ceiling Diffuser On Diffuse Ceiling Ventilation (DCV) Performance

Diffuse Ceiling Ventilation (DCV) is a promising concept to address the internal comfort requirements in modern buildings. Among various possible configuration, the use of sound absorbing perforated panels is the most attractive since it does not require substantial modification in the design of the suspended ceilings normally present in office room. Numerical simulations are a valuable tool to evaluate the performance of a DCV avoiding the cost of an experimental campaign. As today, all the numerical studies are usually carried out by modeling the perforated ceiling as a porous medium, focusing more on its general performance than on the optimisation of the diffuser design. In a previous study by the authors, a CFD model was used to optimise the size and distribution of the dropped ceiling perforation in a room section, modeling the actual perforation of panels. This paper presents the results of simulations carried out using of a full scale numerical model of an office room with DCV with focus on the performance comparison between a continuous and non-continuous ceiling diffuser surface. The results show that the noncontinuous diffuser design does not affect the internal comfort. The air velocity distribution in the room is far below the discomfort limit. In addition, the noncontinuous system does not introduce a significant increase in the total pressure loss of the ventilation system.