Numerical study on the sound insulation potential of the ventilating double-leaf facades

Abstract

Double-leaf facades can be designed to allow natural ventilation while providing adequate sound insulation. The key concept is based on the displacement of the opening in the second layer relative to the opening in the first layer, resulting in a significant improvement in sound insulation compared to a direct opening. This sound insulation can be further improved if the sound absorption in the cavity of the double facade is increased. An extensive laboratory study was conducted to investigate the impact of different variables of such a system (e.g., the size of the openings, the location of the openings, the relative displacement of the openings in the two layers, the sound absorption in the cavity, the location of the sound absorption panels, etc.) using an experimental modular double wall. Empirical prediction models have been developed to predict the sound transmission through such double leaf facades with open elements. Their prediction is validated by measured data. In this paper, we analyze different scenarios of double leaf facades in building-scale dimensions and we use empirical models to calculate their sound insulation. This offers an insight into the sound insulation properties of a potential real-building double facade.