Enhancing Traditional Building Automation Systems for HVAC Operation Using a Modular IoT-Embedded Real-Time Monitoring Device

Abstract

A fully-custom Internet of Things (IoT) embedded electronic control Hub is proposed as a viable all-in-one solution for retrofitting building automation systems (BAS) with wireless cloud capabilities. Modern IoT-based BAS solutions have not fully addressed the complexity and high costs that come with their installation and maintenance. These solutions lack an all-in-one framework that incorporates all functionalities into a single device, reducing their adoption by commercial building owners. This new IoT Hub addresses the concern for centralized control panels which typically contain the most critical operational measurements for system performance monitoring and optimal control algorithm development, while still providing the core functionalities of an IoT-based BAS solution by delivering on four primary design considerations. First, the IoT Hub provides a unified platform that supports “plug-and-play” user operation. Second, the device provides standardization for environmental sensor interoperability. Third, the device applies a unique semantic data model to characterize collected heating, ventilation, and air conditioning (HVAC) data. Lastly, the device upgrades BAS with the ability to wirelessly transmit HVAC data to a remote database. This paper also presents how the IoT Hub directly addresses these four design considerations by elaborating on the device’s implementation, features, and user-friendly operation. Two sets of experiments are designed and conducted to test the performance of the IoT Hub, through a comparative analysis with a high-precision data logger and an existing BAS’ local data storage infrastructure. The results show good performance of the IoT Hub with R2 values as high as 0.997 and normalized root mean square errors (NRMSE) below 10% for all measured variables (below 1% for $CO_{2}$ channels) when compared with a high-precision reference logger. Finally, areas for future improvements of the IoT Hub were outlined and discussed.