Green walls for building microclimate control

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 cooling systems of buildings, 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 and promote evapotranspiration in summer and increase the thermal insulation in winter. Three vertical walls, made with perforated bricks, were tested at the University of Bari (Italy): two were covered with evergreen plants (Pandorea jasminoides variegated and Rhyncospermum jasminoides) while the third wall was kept uncovered and used as control. Several climatic parameters concerning the walls and the ambient conditions were collected during the experimental test. The daylight temperatures observed on the shielded walls during warm days were lower than the respective temperatures of the uncovered wall up to 8.4°C. The night-time temperatures during the cold days for the vegetated walls were higher than the respective temperatures of the control wall up to 3.6°C.