Thermo-physical Performances of Living Walls via Field Measurements and Numerical Analysis

In the urban area the air temperature has been growing at a faster rate (Urban Heat Island UHI) leading to greater use of air-conditioning and energy demand. One possible strategy to lower ambient temperature is to increase the amount of greenery in the city. In this context we have assisted recently to a rediscovering of buildings envelopes claddings by green walls, living walls and green roofs. Green walls may consist in green façades made up of traditional creepers and living walls are vertical claddings with plants, installed on the building façade. A very detailed field measurement campaign was performed on a living wall with the aim to evaluate its performances versus a traditional envelope. The field measurements were performed between June and September 2011. Hourly measurements of surface temperatures, heat fluxes, ambient and internal temperatures, ambient and internal relative humidity, air velocity in the living wall cavity and climatic variables have been collected for the bare and covered wall. Using a numerical model, validated via field measurements, a multiparametric analysis has been performed considering the effect on energy consumptions and temperature behaviour for different orientations of the living wall in different locations.