Evaluation of Quality of Light and energy-efficiency for lighting systems in secondary schools in the city of Ahvaz

Background and aims:The aim of the good quality lighting is that which balanced the needs of humans, economic and environmental issues, and created suitable lighting for a particular visual activity (e.g. reading, writing, etc.). Quality lighting is very important to incising productivity and learning of students. The main idea of energy-efficient lighting is to reduce the amount of electricity used without compromising on the quality of lighting. The first objective of the work was to assess different aspects of lighting quality and energy efficiency and the second objective was to find out ways to improve the efficiency of electric lighting in high school. Methods: this cross-sectional study was conducted in 11 high schools for girls in Ahvaz. In this regard, based on measured artificial light (lux) and Electrical power consumption (w/m2), Installed Power Density (IPD) (w/m2.100 lux) is calculated. Normalized power density (NPD) divided by Installed Power Densityto compute Installed Load Efficiency Ratio (ILER) and Performance Index classified into three categories. The data were analyzed by a unilateral variance analysis test using SPSS 16. Results: The results show that sum of areas measured, 47.6 percent at level 3, 36.1 percent at level 2 and 16.2 percent at level 1 have been evaluated. Maximum efficiency is reported in three high school (3, 5, 8) lighting systems had the best performance. Conclusion: In this study, Low efficiency and high energy consumption of lighting systems result from defects such as reflection coefficients less than the standard (walls 0.5, ceiling 0.7 and floor at least 0.3), using conventional ballasts instead of electronic ballasts, lamps low-efficiency , conventional Reflectors instead of steel and lack of proper use of daylight.