Evaluating the cooling capacity of diffuse ceiling ventilation system – Full-scale experimental study

Diffuse ceiling ventilation system is an air distribution system in which part of the suspended ceiling made of perforated panels is used as an air diffuser for the supply of fresh air. This method has been proven to have a higher cooling capacity compared to conventional air distribution systems. The cooling capacity of the system, however, depends on several parameters. This paper presents evaluation results regarding the cooling capacity of the diffuse ceiling ventilation system in connection to two essential parameters, i.e. the distribution of heat sources in the room and the ratio of perforated to non-perforated panels in the ceiling. The evaluation is based on full-scale experiments performed in a laboratory controlled environment and using a design chart which expresses the limits on the supply airflow rate and temperature. The experimental results indicate that the highest cooling capacity is achieved when the heat sources are distributed evenly and the perforated panels cover the entire ceiling. In the case of partial coverage, the cooling capacity is reduced when the heat sources are placed below the perforated panels. The system can have a higher cooling capacity in the partial coverage configuration compared to the full coverage one depending on the supply airflow rate.