Verde verticale e comfort termico negli edifici. Valutazione delle prestazioni di una parete verde in area mediterranea

The energy consumption of buildings and the associated CO2 emissions are causing an increase in global average temperatures of the planet. In dense built-up urban areas, the microclimate is gradually changing and the temperature increase may imply long lasting heat waves in summer along with negative impacts on the health of the city residents. A possible solution is represented by green façades; they can bring significant thermal benefits to the buildings in which they are placed through the shading and evapotranspiration of the foliage, resulting in a reduction in both the external surface temperature and that of the internal environments. This paper aims to evaluate the effectiveness of a green façade as a strategy for the improvement of indoor thermal comfort in a prototype lightweight building, as well as understanding the effects on the surrounding outdoors based on the outer surface temperature achieved by the walls. To this purpose, a micro-scale analysis of two lightweight prefabricated modules, one equipped with a green façade and one not, located at the University Campus of Catania is performed by evaluation with simulation software. The analysis was carried out for assessing the thermal behavior induced by an advanced vegetated vertical screen realized using the Trachelospermum jasminoides (commonly known as “false jasmine”) installed on the west-facing wall of one of the two prefabricated modules. The simulation outcomes highlighted a medium reduction of about 4°C on the external surface and of 2 ° C on the internal one, as well as a decrease in the internal air temperature of about 1°C. This shielding has been installed on the prefabricated modules for some months now and, at the end of its growth, it will be monitored for a year in order to verify the results obtained through the simulation.