A wireless sensor and actuator network (WSAN) framework for personalized thermal comfort in office buildings

Recent advances in wireless technologies, MEMS and embedded systems enable the popular usage of wireless sensor networks(WSNs) and subsequently WSNs with actuating capability known as WSANs in various automation systems. This paper provides an implementation framework for wireless sensor and actuator network (WSAN) to support research experiments in personalized thermal comfort for existing multi-occupancy offices. The proposed framework facilitates environmental and user preference data collection, analytics and actuation of the local comfort devices with minimal retrofitting. Commercially available fans are integrated with wireless sensor and actuator node to act as the local comfort devices for the users. The framework can be operated in three different modes: Manual, Auto and Hybrid to account for the various applications. A method for air speed estimation based on the ASHRAE Standards 55-2013 is described to demonstrate the actuation of the fans based on a thermal comfort model. This paper also suggests future directions on how the framework can be used to enhance thermal comfort and minimise air-conditioning energy consumption.