Retrofit of air conditioning systems through an Wireless Sensor and Actuator Network: An IoT-based application for smart buildings

This paper presents the usage of Internet of Things concept as a tool for retrofitting air conditioning systems. The proposed technology consists in an embedded system developed with an open-source hardware platform and connected through a wireless sensor and actuator mesh network. By learning commands from the air conditioner's remote control, the system is capable of implementing automatic control of the air conditioner equipment. Through a central command unit, it is possible to configure timers to turn on and off all devices connected to the network. The system also adds intelligence to conventional equipment by making use of a motion sensor, avoiding electricity waste. An automatic temperature control is implemented through sensors that monitor external conditions. By making use of a mesh network based on DigiMesh protocol, each device acts like a router, increasing network range and making it easier to add or remove new devices. The proposed system was validated through case study.