Development of digital twin system for central air-conditioning based on BIM

With the rapid development of building intelligence, the efficient management and control of central air-conditioning systems have become a research hotspot in the HVAC (Heating, Ventilation, and Air Conditioning) field. The effective integration of BIM (Building Information Modeling) technology and digital twins into HVAC systems enables the visualization of smart operation and maintenance processes, as well as information sharing across complex equipment systems, providing technical support for modeling, simulation, fault detection, and optimized control of air conditioning systems. This paper proposes a BIM-based digital twin framework for central air-conditioning systems. Through secondary development of a laboratory air conditioning system's BIM model, a communication architecture and data-driven logic for the central air conditioning digital twin system is presented. The system is designed and developed using OPC/ UA technology and the Unity platform. Comprehensive performance testing validates the stability and reliability of the digital twin platform, The test results show that, under typical operating scenarios, the platform consistently maintains a CPU frame time within 10 ms, memory usage below 2 GB, script execution time under 10 ms, and fewer than 2000 rendering batches. All functional test cases were successfully passed, demonstrating stable feature responsiveness and validating the platform's excellent performance in response speed, security, and interactive capabilities. These results provide strong technical support for the intelligent operation and maintenance of central air-conditioning systems.