Review Paper A comparative study on details of green walls in different climates

Global warming has today turned to one of the most important environmental issues due to overuse of fossil fuels, and it needs serious attention. Since the mid-1970s, an urgent need was therefore felt around the world to reduce the use of energy for heating and cooling in buildings. Using green covers, especially green facades, in appropriate environmental conditions can be regarded as a method to achieve thermal comfort while maintaining the building energy consumption low as well as reducing greenhouse gases emission. The present paper investigates the features related to living walls in different climates. Based on results, due to reduced heat absorption, evaporative cooling and low thermal conductivity, the hotter and drier the climate, the higher the efficiency of the green wall as well as temperature reduction will be. On the other hand, using of green walls in temperate and hot and humid climates has a positive effect, but because of the humidity factor, open or closed air layers should also be considered. The green wall surface creates more stable relative humidity in the air layer near the wall surface without increasing the relative humidity of indoor air. At the urban scale in the warmer and drier climates, the green covers will have a dramatic effect on urban temperatures. Using green covers of buildings’ walls, there will be a significant potential for reducing urban temperatures, while the highest efficiency will be achieved with simultaneous application of green surfaces for both roofs and walls.