Nowadays, smart classrooms are becoming more popular. this research work is introducing an innovative approach to reducing/improving energy consumption in smart classrooms at Silpakorn University, Thailand. By integrating the IoT and environmental sensors cooperated with AI-based person detections, the system can effectively monitor and arrange the classroom environment in real-time/continuously. The simulation results showed that the proposed system is capable of regulating temperature, humidity, motion, lighting levels, and accurately counting the number of individuals in the classroom. The notification system serves as an additional layer of security, alerting in the case of any unexpected presence. The research work lays the foundation for further exploration and implementation of energy-efficient smart classroom solutions, which will ultimately benefit both the environment and the quality of education. Keywords— Internet of things, artificial intelligence, energy management, smart classroom, sensor