Green façades to enhance climate control inside buildings

Green technology can represent a sustainable solution for construction of new buildings and for retrofitting of existing buildings, in order to reduce the energy demands of the buildings’ cooling systems, to mitigate the urban heat island and to improve the thermal energy performance of buildings. Green walls can allow the physical shading of the building, promote evapotranspiration in summer and increase thermal insulation in winter. An experimental test was carried out at the University of Bari (Italy) for 2 years. Three vertical walls, made with perforated bricks, were tested: two were covered with evergreen plants (Pandorea jasminoides and Rhyncospermum jasminoides), while the third wall was kept uncovered and used as a control. Several climatic parameters concerning the walls and the ambient conditions were collected during the experimental test. Daylight temperatures observed on the shielded walls during warm days were lower than the respective temperatures of the uncovered wall by up to 9.0°C. Night-time temperatures during cold days for the vegetated walls were higher than the respective temperatures of the control wall by up to 6.0°C. The absence in the literature of data concerning different seasons of the year is overcome in order to obtain a complete picture of building thermal performance in the Mediterranean climate region.