Desempenho térmico de paredes verdes na fachada norte em modelo reduzido: um estudo para a zona bioclimática de Londrina

Abstract

The use of vertical gardens (living wall) is an expanding technology in Brazil, which provides improvements in quality of life in several aspects: air quality, landscaping and comfort. The aim of this study was to evaluate the effect of a living wall on the thermal behavior of the surroundings and the interior of buildings, from the small scale reproduction of a building located at UTFPR Londrina Campus, Block S. two reduced 1:12 scale models were used, with their largest north facing façade and coverings according to NBR 15220 (2005) for the bioclimatic zone of Londrina. Using 15 sensors associated with 2 Arduino plates, data were collected on the external and internal surface temperatures of the façade North, the external and internal air temperature of the two blocks built, one with a vertical garden purchased on the market. The model used is the plastic material, with 27 housing niches or substrate as support for plants. The drip irrigation system and automated control provide 30-minute watering every 12 hours with a flow of 37ml/min. Nine seedlings of one of the following species were used: Aspargus (Aspargus densiflorus), Chlorophyte (Chlorophytum comosum) and Singonium (Syngonium angustatum). It was possible to verify that the use of the living wall promotes a reduction in the internal temperature of up to 8°C (up to 10.4ºC) in relation to the internal temperature of the model without living wall (SPV) and 11°C in relation to the external temperature (EXT), for the peak hours that occurred in the early afternoon. An average thermal delay of the 2 hours (up to 4,1 hours) CPV model was also observed. A lower thermal amplitude inside the living-walled environment was evident, as well as the maintenance of more comfortable temperatures at night (less reduction on cold days). Among the species used, the Singonium was more effective in reducing heat transfer rate, since in the experiment a difference of this thermal rate of 12 watts compared to the conventional coating was obtained. The system of green wall showed up a thermal damping of 42.1% of thermal flux in Aspargus and 80,3% in Singonium. Thus, the studied living wall model can be considered as an effective alternative to decrease the internal temperature of built environments, and generate energy savings.