Sound Absorption Properties of Different Green Wall Systems

Building façades predominantly consist of robust materials which either reflect or scatter sound emitting from sound sources, especially from main roads thus increasing the urban noise and negatively affecting the sound environment. Applying green walls to building facades can be a nature-based solution to decrease this urban noise. Green walls are divided into two: multi-layer and more complex living wall systems, where the growing medium (soil or felt) is located on the building façade, and another type is green façade, the ivy-type plant covers the building façade. This research aims to compare various green wall systems to determine their efficiency in terms of sound absorption purposing to identify the most effective option. Sound absorption at normal incidence of 4 different green wall systems measured via impedance tube in accordance with TS ISO EN 10534-2 standard for 50-6400 Hz. Euonymus fortunei, an evergreen plant, was used in the study. Either peat soil or felt served as the growing medium. The results suggested that soil-based living wall systems exhibited greater sound absorption compared to other types, with felt-based systems following closely behind. The sound absorption value was found to be lowest when the plant was applied only as a green façade.