Abstract: The fan coil unit (FCU) air-conditioning system is a typical air-conditioning system in buildings. However, due to its complexity and concealment, traditional practical teaching is confined to site visits and observations, making it difficult for students to gain an in-depth understanding of its operational regulation methods and to improve their energy-saving awareness. To solve these problems, the paper employs virtual simulation technology to develop a virtual simulation experiment for the operation and regulation of a FCU air-conditioning system. For two typical types of FCU—three-speed and DC brushless, a simulation model of the FCU air-conditioning system is established using the Dymola dynamic simulation software to replicate the real system’s operating characteristics. Unity software and Socket communication technology are utilized to recreate actual application scenarios, providing an immersive interactive experimental environment. Through the design of experimental modules such as equipment assembly and disassembly, control system wiring operation, real-time operational regulation feedback, and timed quiz questions, the experiment becomes more engaging. Application results demonstrate that the experiment effectively improves students’ understanding and knowledge of FCU control design, regulation principles and energy-saving strategies.