Application of Computer Simulation and Multi-objective Programming Model for Horizontal Perforated Shading Device

• Main Authors: Yu-Ting Chang, 張瑀婷
• Other Authors: 周鼎金
• Format: Others
• Language: zh-TW
• Published: 2013
• Online Access: http://ndltd.ncl.edu.tw/handle/rpcr6x

碩士 === 國立臺北科技大學 === 建築與都市設計研究所 === 101 === In subtropical Taiwan, ‘external shading’ is an important energy-saving feature in the design of building shells. Placing external shading at the opening of a building can meet the need for protection from the sun, thus reducing air conditioning load. On the other hand, this reduces the efficacy of interior natural lighting, th-ereby increasing the need for artificial lighting. This clearly shows that the two aspects of external shading, protection from the sun and lighting, are contradictory. Therefore, the question is how to find a compromise that can achieve maximum energy efficiency when various constraints hinder the accurate implementation of standards and rules. This study attempts to help decision-makers with a planning approach based on mathematical concepts. Its formula converts multiple objectives and constraints into a proper equation and the best solution is obtained by solving the equation with an appropriate method. The calculation of the equation created with the object-tive and conditional functions defined in this study reveals that perforated horizontal external shading with a perforation rate of 8% is the optimization model. Quan-titat-ive data and images from computer software simulation further reveal: (1) Sunlight can directly enter into the experiment house without external shading, bringing the indoor daylight factor to 2%. This in turn increases both indoor heat load and consequent air conditioning load. (2) In the experiment house with external shading, air conditioning load is red-uced because the shading blocks most of the sunlight. However, the daylight factor is clearly lower. (3) In the experiment house with perforated horizontal external shading, the shading can block part of the sunlight while allowing an adequate amount of light into the house. (4) In the experiment house with perforated horizontal external shading that has a perforation rate of 8%, simulations of energy consumption in air conditioning and natural lighting using aperture diameters ranging from 0.4 to 5 cm reveal that the size of aperture diameters has an impact on natural lighting. By analyzing the data from these simulations, the aim of this study is verified. Therefore, the mathematical model for the perforated horizontal external shading built with the multi-objective planning approach and the Ecotect visualized environment for energy efficiency analysis and simulation can be used by building designners for evaluation in the design planning stage to successfully achieve the goal of energy efficiency in buildings.