A Comparison of Daylight Prediction Methods

ABSTRACT: Daylight plays an important role in architecture. Apart from being a free source of energy that is virtually limitless, it affects the performance of human psychology. People physically become not only more active but have a positive mental state to tackle whatever the workplace throws at them. The first and the most obvious thing to understand about natural daylighting is that daylight is variable. It varies along with the seasons of the year, the time of day, and varies according to the weather. In spite of the amount of daylight penetration, making sure that not too much enters is also a challenge since it may create bigger problems such as glare or overheating. Although using daylight is extremely economic and energy efficient it should be well designed and controlled in order to maximize these traits. One of the solutions to overcome such problems is the use of daylight prediction methods. In this research, four different daylight prediction methods are used in order to calculate the daylight factor, focusing on an overcast sky condition in a case study which was a design studio in E.M.U university of North Cyprus. These methods were explained and used in order to estimate the available daylight factor to maximize the efficiency and reduce the carbon footprint of the building. Both quantitative and qualitative comparisons were utilized in order to analyze the results. This comparison visualized the characteristic of each method. This study verified the fact that the implication of each method has different perspectives and according to the needs of the user, a decision can be made on which method to utilize. This study focused on light from an overcast sky and can be furthered by researching the effects on the daylighting with the direct rays of the sun instead of an overcast sky. Key words: Daylight factor, Prediction method, Overcast sky. ……………………………………………………………………………………………………………………………………………………………………………………………………………………