Evaluation of effects of a green wall as a sustainable approach on reducing energy use in temperate and humid areas

Abstract

Nowadays, with the advancement of construction technology, saving energy use of the building has been considered as one of the fields of environmental sustainability. The use of green cover and plants on the buildings is a suitable passive method that leads to the replace reduced urban green spaces and reduce the problems caused by the effect of the urban heat island (UHI) and improve the energy performance of buildings by reducing the indoor temperature, regulating humidity and creating thermal insulation. The objective of this study was to evaluate the reduction of energy consumption through the green walls of an educational building in Gorgan (Csa climate). For this purpose, first, a building designed on the university site, and the effects of two methods of constructing green walls by using three different plant species were simulated. For comparison, thermal data of a building with a direct green facade in the same climate was measured as an experimental sample, and the results were used in the simulation. The effects of using two methods of a green wall with three different plant species (Sedum, Parthenocissus tricuspidata, Hedera helix) were simulated, which Sedum has had better results than other species. The final results showed that the latent heat of the building is increased by green walls and less significant heat is generated in the environment than buildings without green cover. Also, in buildings with living green walls, compared to buildings with direct green facades, the thermal transmittance of the wall is reduced due to more material layers. The results show that some types of green walls reduce heat loss, and finally the total energy use of the building. The green wall has a more efficient effect on the buildings with a simple form and the limited number of interior spaces. In general, depending on the variables of each building, the use of green walls with plant species is different. It is better for a building before design, to determine the most appropriate method of constructing a green wall and plant species to reduce the energy usage according to project factors and climate type of the region.