An approach for simulation-based multi-objective optimization of dynamic shading devices

Abstract

The increase in the average temperatures across the world due to global warming increases the cooling requirement in buildings and therefore the amount of energy spent for the cooling. In the office buildings, which are far from being healthy and energy efficient with their high energy consumption profiles, the function-related planning strategies and the curtain glass facade designs mostly designed for prestige purposes. Particularly in the office buildings located in the hot climatic regions, active systems must work to maintain the comfort conditions of the office spaces at an adequate level as a result of the overheating caused by the glass facades. This situation causes high amounts of cooling energy to be consumed. Similarly, the glass facades affect the visual comfort levels in the office spaces and therefore the amount of energy spent for the lighting. In the office buildings, ensuring thermal and visual comfort with minimum energy consumption requires reconsidering the facade design with a holistic approach. It is seen that when the effect of the glass facades on the office building facades, due to the indoor comfort conditions and therefore on the energy expenditure, can be controlled with passive systems, both the user's comfort conditions can be ensured and the building energy performance can be increased significantly. Shading devices are the most important passive design strategies that are effective in preventing excessive solar radiation gain and thus overheating, thus reducing the amount of energy spent on cooling. In addition, the control of daylight, which is the primary lighting source, with shading devices contributes to providing visual comfort conditions with minimum energy. Shading devices are facade systems designed to protect the interior spaces from excessive direct and indirect solar radiation, and they are integrated into the building envelopes. Shading devices also reduce the energy and operating costs of the cooling systems by blocking the solar radiation; however, this situation creates an inverse relationship between the energy required for the cooling and the desired level of the thermal comfort. It is known that cooling has become a priority in design decisions today due to overheating and temperature increases caused by the climate change. Under these conditions, dynamic and climate-adaptive building envelope design should be considered to make building facades more than just a shell. Especially in hot climate regions, designing the glass-facade office buildings to provide thermal and visual comfort conditions while consuming minimum cooling and lighting energy has become a priority design problem. Achieving several goals with different purposes during the design process is possible with multi-objective optimization tools. Optimal values of all variables related to the design can be provided with the help of genetic algorithms that allow input data to be received and the outputs updated accordingly. Genetic Algorithm is a search and optimization method that works similar to the evolutionary process observed in nature. Therefore, this research proposes a new approach for simulation-based multi-objective optimization of dynamic shading devices for an office building located in a hot and humid climate, starting from the very beginning of the architectural design process. The approach aims to increase the thermal comfort in the interior while reducing the cooling and lighting energy consumption of a glass-facade office building located in the hot and humid climate region of Turkey.