Design and analysis of an automated power control system for smart buildings using IoT communication protocols

The rapid growth in the urban population leads to the construction of buildings for commercial and residential uses. The key aspects of a building management system are to control heating, ventilation, and air-conditioning (HVAC), lighting, and other systems efficiently. Most of the smart solutions reported in the literature rely either on Wi-Fi or Bluetooth for local device connectivity and often use an application layer protocol such as MQTT for remote data management and control. To address this limitation, this paper presents a smart IoT system prototype for automation and control of HVAC, lighting, and other systems using integration of Bluetooth, Wi-Fi, and the MQTT protocol to enable reliable and flexible operation. The proposed system allows devices to operate independently via MQTT over Wi-Fi or Bluetooth, thereby improving system robustness in the event of network failure. The system is particularly effective in hazardous conditions such as short circuits, earthquakes, and fires, as the devices and power supply can be controlled without any physical access to the affected area. Furthermore, cloud-to-device latency is analysed to test the responsiveness of the system; the average cloud-to-device latency is observed to be 686.44ms. Since IoT systems are often deployed in power-constrained conditions, a comprehensive power consumption analysis is performed under different test conditions. The experimental results show that the average power consumption ranges from approximately 310 mW to 1100 mW under different test conditions and operating modes. The data can be utilized to implement power optimization strategies for energy-efficient operations.