Determination of building shape for energy efficiency using simulation and particle swarm optimization

Abstract

The building envelope shape is the most salient design characteristic and has a significant influence on energy consumption during the post-occupancy service life. However, during the conceptual design phase, envelope shape-finding is defined without considering post-occupancy service life energy performance. This warranted absence of a priori knowledge on shape-based convective heat transfer affects indoor environment quality and impedes the ability to meet post-occupancy energy performance efficiency requirements. In addition, there is no suitable method for designers by which to make such calculations. In an attempt to optimize energy consumption and reduce the post-occupancy service life in efficiency, this research aims to determine building shape energy efficiency using a simulation and optimization process that can facilitate the designer’s task during the conceptual design phase. For this purpose, a case study research method and simulation-based particle swarm optimization process was conducted. Foremost, it is pertinent to understand building shape behavior in order to improve energy efficiency. For this, a longitudinal case study set out to collect real time energy data and historical building data by a selected unit of analysis Block C 02, Faculty of Geoinformation and Real Estate, Universiti Teknologi Malaysia. The building shapes were simulated using thermal transient simulation for heat transfer analysis. However, results indicated that a proportionate increase in building shape compactness, aspect ratio or coefficient can adversely affect building shape thermal performance, affirming the proposition that convective heat transfer and solar radiation have a considerable influence on energy consumption based on shape geometrical characteristics. Following this, a varied combination of shapes, wall window ratio and glazing energy performance was then analyzed using particle swarm optimization to determine the optimal envelope shape combination. The results confirmed that, as the shape achieves its geometric efficiency, it appropriates the wall window ratio and glazing proportions that reduce convective heat transfer. A design approach that can determine shape energy efficiency based on simulation and particle swarm optimization was then developed. Further, sensitivity of this design approach was calibrated using comparative testing and empirical validation. The findings provide a benchmark of energy consumption based on a combination of envelope shape characteristics, wall window ratio and glazing. In conclusion, this research has succeeded in transforming the conventional shape-finding process into an integrated simulation-based shape optimization for energy efficiency. The major contribution of this research study was that it developed a design approach for building shape energy efficiency and optimization. It can facilitate the task of designers during the conceptual design phase by disposing of their one-off design solutions and making it feasible to conceptualize varied building shapes for energy efficient design solutions.