ENERGY SAVING IN BUILDING AUTOMATION USING ZIGBEE WIRELESS NETWORK AND FUZZY CONTROL

Abstract. This paper presents results of wireless intelligent building automation focusing on the rational use of energy without prejudice to the thermal comfort. The wireless approach, in this work, could better target retro-fitting of buildings still in operation, a great HVAC market share in Brazil. We used split air conditioners, power meters and temperature sensors, forming a ZigBee wireless network of sensors and actuators. A supervisory computer integrates all measurements and command signals. The thermal regulation of a laboratory environment was implemented with Atmel ATmega8 microcontrollers and XBee transceivers. Through the use of information not generally used in building automation (outside temperature, estimation of number of persons in the room and dynamic load sharing between the air conditioners) we could reduce significantly the energy consumption while maintaining the thermal comfort sensation. We compared classical on-off and fuzzy control strategies. The fuzzy system, an expert rule based inference machine, could better take care of the different contexts in the building automation. We verified that both controllers were able to maintain the thermal comfort; however, the fuzzy controller attained it with lower energy consumption (reaching 30 % savings in some situations)