A Study on Daylight Performance Evaluation in Primary School Classrooms

From the early beginning of construction in history, priority of using daylight has played an active role in the settlement decision, building shape and façade design. Today, the necessity of conscious consumption has become an accepted fact due to the depletion of energy resources. For this reason, the effective use of daylight and reducing lighting energy consumption have become one of the most important goals of today's architecture. The purpose of the natural lighting system is providing sufficient daylight to the target area, considering the visual comfort conditions. Nowadays, for the architectural design of buildings, the use of passive systems is primarily preferred in terms of energy efficiency. The use of natural lighting as a passive system, minimizing building lighting energy requirements and creating the desired visual environment should be prioritized in terms of providing visual comfort. In educational buildings, it is vital to design a lighting system in which daylight is used effectively in order to meet the visual needs of the instructors and students and to minimize the usage of lighting energy. Within the scope of the TS EN 17037 standard, which was developed for daylight assessment in buildings and approved by CEN on 29.07.2018 and lastly updated on 02.03.2022, the criteria for daylight assessment is handled under 4 headings: daylight provision, view out, exposure to sunlight and protection from glare. For each criteria specified in indoor daylight assessment, three grades are defined as 'minimum, medium and high'. In this study, the criterion of providing daylight in educational buildings was examined in accordance with the TS EN 17037 standard. With the study, it is aimed to develop an approach to determine the optimum values ​​of the parameters of direction, obstacle presence and transparency ratio in the context of providing sufficient daylight in the primary classroom design. Investigated building type is the primary school building classroom, which was created in optimum dimensions according to the characteristics of primary education classrooms defined in the ‘Educational Buildings Minimum Design Standards Guide’ published by the Ministry of National Education. It is aimed to evaluate and develop the criteria given in the ‘Educational Buildings Minimum Design Standards Guide’ according to the TS EN 17037 standard, which defines daylight performance in Turkey. The classroom model discussed within the scope of the study has been modeled with the Rhino program according to the alternative transparency rates and obstacle situations; In the simulation, the Climate Studio plugin, which was developed for the calculation of dynamic evaluation parameters, was used. The area handled by using evaluation methods according to the 17037 standard included in the software was evaluated in terms of annual daylight performance. The availability of target illuminance levels in half of the daylight hours throughout the year was calculated using the daylight autonomy method, and the climatic data of the province of Istanbul were used as a representative in the calculations. The results obtained were evaluated according to the TS EN 17037 Daylight Standard, and the scenarios created were classified as 'minimum, medium and high' according to the availability of daylight. According to this classification, optimum transparency ratio, window direction and obstacle conditions conditions for the city of Istanbul in primary school classroom design are discussed. The optimal transparency ratios for each aspect are discussed. The minimum transparency ratio values ​​given in the ‘Educational Buildings Minimum Design Standards Guide’ were compared with the optimum transparency ratios obtained.     Keywords:   Daylight Performance, TS EN 17037, Primary school classrooms, Window Design