Investigating the thermal and acoustic performance of a modular living wall: a case study using bioclimatic and reverberation chambers

The potential benefits that green walls systems could offer buildings, and the urban environment are widely accepted. However, predicting and quantifying these benefits is both challenging and time-consuming. Most experimental studies reported took months or even years, often using large-scale outdoor prototypes under unreproducible conditions. In this case study, the authors report the application of a laboratory bioclimatic system, capable of replicating indoor and outdoor conditions in two contiguous chambers, to evaluate the thermal performance of a modular living wall made from recycled plastic under Portuguese Mediterranean summer and winter scenarios. It also describes the use of a reverberation room to examine its acoustic behaviour in terms of sound absorption, measuring reverberation times by frequency in one-third octave bands, between 100 and 5000 Hz. Temperature differences of up to 3.4 °C and 4.1 °C were observed on the external surface of the living wall compared to the reference uncovered wall in summer and winter conditions, respectively. Additionally, the living wall exhibited high sound absorption coefficients at frequencies above 250 Hz. This study highlights the potential benefits of modular living walls, while describing laboratory tests that can effectively evaluate their thermal and acoustic performance.