The Suitable Density of Vertical Greenery Systems on Office Buildings for Energy Saving

Abstract

One of the more optimistic strategies to generate energy savings in buildings and help mitigate the effect of the urban heat island is to “green” the building envelopes. In general, a vertical greenery system (VGS) has excellent possibilities for cutting building energy use, particularly during cooling periods. One of the most important factors is the shadow effect factor, which is greatly affected by the plants. Simulating the facade foliar density using Revit energy analysis is one technique to describe the potential shadow effect of flora. This paper will analyse and investigate to answer the following question: Does the variation in density of the VGS affect the energy savings of the building? The VGS has several factors that affect the energy savings of the building, such as the types that thrive in each region, the facade’s direction, the thickness of the foliage, the presence of air layers in the context of green walls, and the makeup and thickness of the substrate layer. This paper will focus on one factor: the density of the green vertical system. The goal of this study is to develop a standard and simple method for calculating the leaf area index (LAI) and connecting it to the energy savings offered by VGS studies on the office building. Additionally, research was done on the energy savings made at the “Karim Centre”, an office building located in Tripoli, Lebanon. Moreover, the facade direction has many impacts on the indoor thermal system that affect energy savings using the VGS, including green walls and double-skin green facades. There is, however, a dearth of information on operating during the heating season as well as throughout the entire year. This paper will discuss the four evaluation variations of the density of VGS on the facade of the office building, resulting in the suitable density of VGS4, which saves 15.7% less energy with 50% green density on the facade.