Assessment of sound insulation of naturally ventilated double skin facades

The sound insulation spectrum is analysed of 18 double glazing arrangements facades, of which 9 double skin facades were measured in situ and 9 in a laboratory setting. The influence of the cavity thickness, the parallelism of the two glass panels, the absorptivity of the cavity and the effect of the size of ventilation slots are investigated. The results are compared with double layer wall insulation prediction models. Also a new, simple model is proposed that predicts the sound insulation of naturally ventilated double skin facades, based on the coincidence frequency, the structural resonance frequencies, the cavity resonance frequencies, the façade construction, the dimensions the and material properties. The model predictions are validated by measurement data.