Evaluation of the vertical greenery system efficiency on the thermal behavior of conventional residential buildings in hot and arid climate, Isfahan province

The conscious use of plants in the design of buildings is one of the low-cost solutions for optimization that is expanding. Therefore, as one of the most effective foundations and concepts of sustainable development in architecture, the vertical greenery system plays a significant role in reducing energy consumption. In this study, considering the structural diversity of the vertical greenery system, the effect of the green façade with six types of climbing plants on the thermal performance of the conventional residential building in Isfahan province has been investigated. For this evaluation, the parameters such as plant leaf area index (LAI), distance between plant and wall (zero, five, ten, fifteen and twenty cm), thermal conductivity coefficient and plant placement height (ground floor, second and fourth floor) have been measured. At first, by testing selected climbing plants (six species), the leaf area index was collected with a photographic camera and Photoshop software, and the thermal conductivity coefficient was collected with an infrared thermometer and the Lux-Lightmeter program. Then, with the data obtained from the coefficient of thermal conductivity, simulation was done in Design-Builder software to determine the effect of the green façade in the summer and winter solstice on the thermal performance of the building. After classification and data analysis, Lonicera Japonica plant with leaf area index of 10, thermal conductivity coefficient 0.21 w/m2.k and air layer of 20 cm on the ground floor was selected as the optimal condition. Other findings include the direct relationship between the leaf area index and the thermal performance of the building and the inverse relationship between the air layer between the green façade and the external wall. Also, the height component of the plant in the floors compared to the ground floor reduces the penetration of heat into the indoor environment.