Optimization of daylight utilization in energy saving application on the library in faculty of architecture, design and built environment, Beirut Arab University

Abstract

Considering that reading and research are the main functions of use in libraries of all educational facilities, proper lighting becomes a crucial factor in the overall success of a library design. In this framework, daylight is essential for both energy saving and improvement of the quality of life in newer buildings where visual tasks are more diverse, and technology poses new types of lighting requirements. Furthermore, emphasis on the importance and methods used to utilize energy will be implemented; provided by nature as the first step in achieving optimum energy saving and reducing our dependence on fossil fuels. Thus, this study will examine the conditions of indoor daylight and the library’s energy performance in the faculty of Architecture, Design and Built Environment, Beirut Arab University with various architectural elements including space depth, window size, external obstruction angle, and glazing visible transmittance. This is done by first analysing the existing situations of daylighting (using Autocad Ecotect software), the situation of the artificial lighting inside the space (using Dial DIALux software), and the behavior of the users throughout the day (using Hobo loggers). Then, the outcomes will be analyzed to specify the challenges, therefore providing solutions related to environmental, technological, and energy saving as well as sustainable and green building designs. As a result, daylight designs based on hollow prismatic light guides are proposed. These designs act as luminaires increasing guide efficiency and uniformity distribution of natural light into the library spaces. The proposed designs are configured and analyzed by ray-tracing simulations for achieving high illumination levels and uniform lighting in the working plane of the library.