Lighting - the way to reducing electrical energy demand in university buildings in Bangladesh

Lighting is one of the dominant electricity demand factors in the building energy sector and has huge potential for demand reduction. However, concerning the efficacy of energy consumption, this potential energy-saving option entails further investigations, particularly for developing countries. This study addresses the issues of an efficient lighting system design for educational institutions with particular attention to classroom and laboratory lighting systems for a university in Bangladesh as a case study. Measurements show that during the daytime, under clear and average sky conditions both rooms received sufficient natural light (>300 lx) for educational activities, whereas under an overcast sky, only 50% space receives sufficient natural light. At night, the installed fluorescent tube lights illuminance level was found insufficient (<300 lx) for educational activities. The inefficient lighting system design was found to be the main reason for this illuminance level. Simulation results reveal that light emitting diode (LED) tube lights with a maintenance factor of 0.8 could save 10,080-15,120 kWh, 91,929-137,894 BDT (1USD=84BDT), and 6,753-10,130 kgCO2-eq, energy, cost, and, greenhouse gas emissions respectively per year for the classrooms.