Architectural Design Based on Daylight Utilization- An Approach for Library Design in Tehran

Todays, excessive consumption of energy is a critical issue for communities. About 40% of energy that used by people is consumed in buildings. Therefore, buildings could be the greatest threat for energy resources. So, architectures play an important role in the decrease of this threat. Unfortunately, energy consumption is increasing in undeveloped countries such as Iran. Daylight utilization in buildings is appropriate not only for considering aesthetic and behavioral aspects of users, but also for preventing energy shortage as well as to reach sustainability goals. Necessity of this study can be stated as follows: emerging of global energy crisis, important influence of lighting in increasing of efficiency of studying and design of dysfunctional buildings in lighting field in Iran. This paper examines different methods of lighting design in terms of the following aspects in order to provide a design framework for lighting in a library. 1. Situation of building in site, considering overshadowing of adjacent buildings and surveying of sunlight paths in the region 2. Buildings volume, including aggregation, porosity and geometrical traits of the buildings in the region 3. Ways of entrance of daylight, this comprises two principle ways off, pass-through component and conduction component. The recent component includes two types of intermediate space and interior light space. 4. Promoting systems of day lighting quality, including solar shelter, transmission, and dispensation that the latter case is divided into light shelf, mirror louvre, prismatic glazing, and prismatic film. This framework intends to achieve the maximum daylight utilization in each stage of design activities. For grasp this purpose after examination various methods, we develop an instruction for designing of lighting in a library. In this project, a library is designed with utilization of the described instruction and with attention to conditions and needs of selective functions in Tehran. In our plan, a lighting system has been designed in roof of study hall of the library that is adjusted with the sun path. This design increases the time period of daylight utilization. This system includes 120 mirrors on the roof of atrium of study hall that are changed their orientations coordinately with sun path. Further, there are suspended reflectors under the roof that receive sun rays from those mirrors and reflect to light shelves that are contrived under roof of floors bordering the atrium. Then reflected light from light shelf penetrates depth space of floors and causes quality of lighting entrance. In this design, we increase possibility of utilization of northern and southern daylight as a result of shaping linear volume and make open space in building that contain court yard and atrium. Our design also promotes quality of interior lighting with preventing direct sunlight from penetrating to indoor. For achievement to this aim, projection of building in southern façade and design of light shelves were very effective. We try to enhance quantity and quality of day light in interior spaces of building. We are hopeful that our design instruction can be a practical framework for other designs in natural lighting field.