Evaluation of Natural Lighting in the Architecture of Educational Spaces in Temperate and Humid Districts with Emphasis on the Efficiency of Light Shelf

School buildings are the second place students spend most of their time after residential environments. Based on this, using natural light will lead to maintaining and improving health and creating visual comfort and sufficient lighting. The present study aims to evaluate the lighting in the classroom environment and create adequate lighting after installing the light shelf in a moderate and humid climate in a proposed model. In the first step, the importance coefficient of the fields and the factors and variables effective in evaluating the brightness of the light shelf were identified. In the second step, the field information of schools in Mazandaran province, especially Sari City, has been collected. In the third step, six different models of the combined light shelf are proposed based on geometric and dimensional characteristics such as depth, height, and angle of the light frame. The results have shown that the combination of the outer light shelf with the internal light shelf is suitable if the outer light shelf with a depth of 120 cm is placed at a height of 1.80 meters from the floor and with a change in its geometric shape at a depth of 30 cm by -10 degrees failure to occur. Analyzing the spatial adequacy indicators of daylight (sDA) also shows that 72% of the students have received lighting above 300 lux and its sDA is equal to 55.41%, indicating sufficient lighting above 300 lux in the class space.