An expert system for lighting energy management in public school facilities

Abstract: Lighting accounts for a large part of the energy expenses of a facility, ranging from 40% to 60% of the total energy cost. Therefore, it represents a critical factor to consider in any energy management program. Lighting audits involve complex energy calculations, such as the estimation of light intensity per square unit area, quality of illumination, and required number of light sources to obtain an adequate illumination level in the facility. In this paper we discuss the development and implementation of an easy-to-use expert system for lighting energy management in public schools. The prototype computer-based system can evaluate 11 different areas of a school facility, and it can identify suitable lighting solutions from 17 distinct bulb types and 38 ballast types. The system determines a facility's required number of bulbs, and it performs the cost and saving analysis of its final recommendation. The constructed expert system was successfully validated by two human experts through two case studies, involving the evaluation of a conventional classroom and a medium-size office.