Visual Discomfort Analysis as a Tool to Support Façade Shading Design: A Case Study in the Architectural Design Studio

Abstract

While daylight admittance in educational buildings is of high importance, the associated visual discomfort issues can negatively impact student productivity and well-being. This paper reports the outcomes of a case study of the architectural studios at Al-Azhar University, Cairo, where visual discomfort due to daylight intrusion was reported by 49% of the students, leading to difficulties while performing multiple vertical and horizontal tasks. To address this issue, visual discomfort simulation analyses were conducted for 78 view positions with respect to façade shading systems (fixed shading and dynamic electrochromic glazing). To predict the level of visual discomfort for multiple view targets, three indicators, horizontal illuminance, vertical-eye illuminance, and daylight glare probability, were used. A simulation workflow of daylight and glare was developed to shade each dynamic window individually whenever the defined criteria are met. The results showed evident reductions in the hours of visual discomfort based on the three indicators from 83%, 84%, and 37% to 8%, 19%, and 3%, respectively (southwest), and from 57%, 71%, and 13% to 2%, 10%, and 1%, respectively (northeast). The proposed simulation workflow can be used in future practices to improve façade-shading performance to protect against visual discomfort under similar climatic contexts.