Abstract
Buildings’ envelope design decisions are usually determined by the architect or designer from the early stages of design. These decisions have a major impact on the comfort conditions and energy performance of buildings. Balancing daylighting levels in school buildings with the energy use is essential due to the physiological, psychological, and behavioral effects of daylight on human body, known as the non-image forming (NIF) effects of light, as well as its impact on the energy use. This study uses multi-objective optimization (MOO) to find the optimal classroom design that has the best overall performance in terms of daylighting levels at the horizontal desk-plane for image-forming (IF) or visual benefits, daylighting at the vertical eye-level for NIF benefits, and the total energy use of classrooms. The study optimizes two classrooms connected to double-loaded corridor from the Department of Energy (DOE) primary school reference building. The optimization parameters include the classroom geometry (width, depth, and height), the window dimensions (width and head height), and the orientation. The impact of the location factor is explored by optimizing the same model in the mixed-humid, hot-humid, hot-dry, and cold climate zones of the U.S. The results indicate that the 3:2 width-to-depth plan shape in most optimal solutions performs better than the 5:4 width-to-depth plan of the reference model. Accordingly, wider windows and higher head height in the optimal design were able to allow more daylighting to the depth of the oppositely oriented classrooms while reducing the energy use. The results show that optimal classrooms’ design connected to double-loaded corridors, including window dimensions, orientation, and window to wall ratio (WWR) vary by the climate zone or location.