Influence of acoustic membrane on sound and thermal properties of building façade panels

This paper compares the acoustic and thermal insulation performance of an extruded polystyrene (XPS) sandwich panel with either one or two additional layers of acoustic membrane of similar overall thickness of 28mm. Samples were prepared by bonding single and double layers of mass-loaded vinyl (MLV) membrane between extruded polystyrene (XPS) core and aluminium facings. Results show that the presence of a single MLV sound barrier layer resulted in a three dB improvement in weighted sound reduction index (Rw) over one-third octave band centre frequency of 100 Hz - 3150 Hz, Rw increasing from 35 dB to 38 dB. The addition of two layers led to an Rw increase of only a further dB to 39 dB. However, the weight of the panel increased from 9.4 kg/m2 to 13.8 kg/m2 for the single MLV layer and to 19.2 kg/m2 for the double MLV layer. The thermal transmission (U-value) with one layer of MLV membrane increased from 1.08 Wm-2K 1to 1.14 Wm-2K 1, an increase of 6% whereas a 12% increase in the U-value was found for the double MLV membrane (1.21 Wm-2K 1) as a result of reducing the thickness of the XPS to accommodate the MLV layers. The addition of MLV membranes, therefore, enhances the sound insulation performance but to the detriment of weight and thermal characteristics.