Influence of the active irrigation system on the vegetation façade

Abstract

Urban population growth has resulted in land use changes and the replacement of many vegetated areas with hard dark surfaces. The altered surfaces warm the urban climate, a phenomenon known as the urban heat island (UHI) effect. Green systems such as vegetated facades significantly affect the outdoor microclimate through evapotranspiration cooling. In particular, the method of irrigation has a major influence on evaporation efficiency. This paper investigates the effect of an active vegetated façade irrigation system on the surface temperature behaviour of the envelope. The maximum difference between the surface temperature of the actively irrigated vegetation wall and the vegetation wall irrigated by hourly interval was almost 14°C. When comparing the surface temperatures of the actively irrigated vegetated façade with the non-vegetated façade - dark cladding, the maximum difference was almost 15°C. The difference between the surface temperature of the actively irrigated vegetated façade and the surface temperature behind the air cavity was almost 9°C. This reduction in temperature results in a shading effect of the vegetation wall. The use of vegetated structures is proving to be an effective tool and mitigation of temperatures in urban environments.