The growing energy demand and environmental concerns have increased the orientation towards energy- efficient and environmentally friendly technologies. In this context, transcritical heat pumps using natural refrigerant R744 (CO₂) stand out. However, real-time monitoring is critical for operating and managing these systems at optimum performance. This study aimed to develop a unique system to monitor and analyze the performance of a transcritical CO₂ heat pump using Internet of Things (IoT) technologies. The system is based on Raspberry Pi and Arduino microcontrollers, various sensors (temperature, pressure, flow, power), a MySQL database, and a dual interface (Lazarus-based local and PHP/JavaScript/HTML-based web). While Arduino collected and processed sensor data using C language, the object-oriented software developed with Lazarus on Raspberry Pi received, processed, stored the data, and presented it on the local interface. Simultaneously, the web interface provided remote access and visualization of the data. The developed system successfully monitored the critical performance parameters of the heat pump (temperature, pressure, flow, power consumption, data required for COP calculation). The results indicate that the proposed IoT-based monitoring system has the potential to increase the energy efficiency of transcritical heat pumps, facilitate operational management, and enable early detection of potential failures.
Özgür et al. (Sun,) studied this question.