Assessment of the impact of green walls on urban thermal comfort in a Mediterranean climate.

• Statistical analysis of the performance of a green wall in a Mediterranean climate. • Irradiance is discarded as a variable affecting the adjacent temperatures reduction. • Maximum reduction of 0.63 °C in summer and 0.54 °C in winter at 1 m from the south facade. • Maximum reduction of 2.3% HR in winter at 1 m from the south façade. • Reduction average of 0.9% HR in summer at 1 m from the south façade. A study has been performed to quantify the impact of a green wall temperature reduction in a continental Mediterranean climate. This paper presents the results of a monitoring campaign during the summer and winter of 2021–2022. First, a database was elaborated with information on air temperature and relative humidity at four different distances from the wall (0.25, 0.50, 0.75, and 1 m) and irradiance in the vertical plane. Secondly, a statistical analysis was carried out to determine whether there is a correlation between these variables and whether there are statistically significant differences between them at different distances from the wall. Results show a strong positive correlation between air temperature recorded by sensors and the ambient air temperature for all seasons and between air temperature and relative humidity in summer. The ANOVA shows that the green wall reduces the temperature and relative humidity with statistical significance for most of the cases. These results confirmed the great capacity of green walls to improve the urban microclimate, especially during summer, by reducing air temperatures, providing evidence that greening the building envelope can complement conventional city green infrastructure and provide multiple ecosystem services to dense urban contexts. [ABSTRACT FROM AUTHOR]