Avaliação experimental da eficácia de sombreamento de sistemas de vegetação vertical

A natural strategy to improve the microclimate of buildings is the use of vertical vegetation systems. Such systems cast shadows on walls, minimizing the rise in temperature on the adjacent surface and the heat gain in the building. Simultaneously, they help restore vegetation eliminated by urban occupation. This research assessed the thermal contribution of vertical vegetation systems as shading elements for buildings in the bioclimatic zone 2. Three already constructed environments with similar characteristics and solar orientation were selected, with the only variation being the shading system on one of the walls. In the first building, a living wall was installed; in the second, a green facade; and the third didn´t get no intervention. To evaluate the shading effect provided by each system, the following environmental variables were measured: internal air temperature, internal and external surface temperatures, and globe temperature. The results obtained confirm the benefit of vertical vegetation systems as a strategy for reducing the internal temperature of the building. The temperature reduction achieved with the living wall was 18.5°C during the monitored period. The reduction in surface temperature of the wall protected by the green facade was 13.3°C during the fall, at times when temperatures are higher, with a low solar inclination relative to the facade. However, in colder periods, the three environments behaved similarly, confirming that vertical vegetation systems contribute to reducing peaks in internal temperature without compromising the passive solar heating needed during cold weather.