A critical evaluation on the impact to urban thermal environment by application of vertical greening to high-rise buildings in high-density cities

Abstract

In recent years, the urban thermal situation becomes worse and worse. Because of the rapid development of urbanization, large quantities of natural vegetation were consumed. Instead of greenery, more concrete buildings, paved grounds and other surfaces with low albedo are appearing, which increases anthropogenic heat emission. This tendency caused more intense urban heat island effect. As the eco-friendly and innovative alternative to urban greenery, nurturing plants on envelopes of building is becoming popular in recent world, especially in the compact cities. The research and study of green roof design and benefits in the thermal and other aspects have been conducted intensively. However, the study of green walls is scanty. Few researches were prone to vertical greening system. Vertical greening as one of the most viable and effective methods to mitigate against urban heat island effect worth more attention to study. This article will take four high-rise buildings with vertical greening in Hong Kong as examples to systematically understand vertical greening and explore the effect on urban thermal environment by vertical greening system.