The Impact of a Vertical Greening System on the Indoor Thermal Comfort in Lightweight Buildings and on the Outdoor Environment in a Mediterranean Climate Context

ertical Greening Systems (VGSs) represent an effective solution for new building design and for existing building retrofitting in order to improve the indoor thermal comfort, decrease the building cooling energy needs and mitigate the Urban Heat Island (UHI) phenomenon. VGSs can reduce the outer surface temperature of walls, and internal temperatures in buildings through shading and evapotranspiration effects due to the foliage. In this study, the authors evaluate the effectiveness of a green façade on the indoor thermal comfort in a lightweight building prototype, as well as its effects on the outdoor surrounding microclimate, through Computational Fluid Dynamic simulations performed in ENVI-met. With this aim, two prefabricated modules, one with a vertical vegetation layer and one not, located at the University Campus of Catania (Italy) are investigated. The CFD analysis is carried out for a preliminary assessment of the effects of a vertical greening layer with Trachelospermum jasminoides, which will be installed on the west-oriented wall of one of the two prefabricated modules. The simulation results have revealed a relevant decrease in the peak of outer surface temperature, and a reduction in the internal air temperature in the hottest hours of a typical sunny day. These outcomes will be further studied by means of measurements campaigns on the VGS during next summer period.