Shading design optimization in a semi-arid region: Considering energy consumption, greenhouse gas emissions, and cost

Today's world is witnessing an increasing concern about energy consumption, Global Warming, and economic crisis; therefore, attention has been paid to the evaluation of environmental, energy, and cost effects in the high consumption building industry not only in the functional stage but also during the life cycle. Considering the importance and sensitivity of educational buildings in terms of energy consumption and environmental issues, as well as considering the economic issues of developing countries, the purpose of this research is to choose the optimal shading in the life cycle of an educational building based on the evaluation of three factors: energy consumption, greenhouse gas emissions, and cost. In this research, a school building in Sabzevar city has been studied. In order to achieve this goal, the energy, economic and Greenhouse Gas emission performance of six common types of external fixed shadings with different materials (PVC, wood, aluminum, and concrete) in the life cycle with the help of energy and environment software, i. e. Energyplus and OpenLCA, were studied. The initial optimization of the geometry of the shading scenarios has been done using the genetic algorithm and the objective functions of lighting, energy, and material consumption. Then, the scenarios have been investigated separately by evaluating each of the 3 E factors during the life cycle. With a comprehensive view of 3 E in choosing the optimal shading, also using the triangle model and the definition of 3 E stability, among 3600 possible options, a simple overhang concrete shading with a projection of 1 m and an angle of 10° to the horizon has been selected as the most optimal structure. Also, the structures of simple overhang and light-shelf with concrete and wooden materials have excellent 3 E stability and are suitable options for design. •Optimizing shading involves assessing energy consumption, greenhouse gas, and cost considerations during the life cycle.•Using a genetic algorithm, the study assessed 30 external shading geometric scenarios for visual comfort.•The most 3E sustainable options were simple overhangs and light-shelf structures using wood and concrete materials.