PRESSURE-EQUALIZED RAINSCREENS - A STUDY IN THE FREQUENCY-DOMAIN

The pressure-equalized rainscreen approach to wall design is becoming more prevalent in Canada. This paper describes a theoretical and exper imental study of the pressure-equalization in rainscreen walls which w as undertaken to improve the understanding of several design parameter s. Primary facto rs which control the pressure-equalization are the le akage of the air barrier, the aerodynamic damping introduced by the ve nting in the rainscreen, and the spatial nonuniformity of the steady a nd fluctuating exterior pressures. This paper discusses each of these via the results of theoretical models, wind tunnel experiments, and fu ll-scale experiments on two separate rainscreen designs. The effects o n pressure drop across the rainscreen of changes in venting area and c onfiguration, air barrier leakage, cavity volume and compartment size are all considered.