Parametric analysis of the airflow performance of ventilators.

In this study a parametric analysis was carried out of the interaction between louvres and various perforated mesh screens. This type of arrangement is common in through-the-wall ventilators used for natural ventilation in buildings. An airflow testing rig was used to examine the impact on louvre airflow performance of the meshes. The interaction of louvre geometries and blade inclinations with meshes of different hole sizes was also investigated experimentally. Airflow measurements through the individual louvre and mesh components in isolation were made and then compared to the airflow through mesh / louvre combinations. Initial results indicate that at low pressure differences the small diameter (less than 5mm) meshes were producing a discernible reduction in the airflow, but that at larger mesh diameters (15 mm) the loss was much less significant. The suitability of CFD software to predict the mesh / louvre interactions has also been investigated.