Zigbee-based Energy Saving Control System for Centralized Air-Conditioning System

With more than a decade of intensive research and development, wireless sensor network has emerged as a workable solution towards multiple innovative applications. However, the usage of electricity, especially in old buildings and with a centralized system, is still not optimized. Therefore, to overcome this, an energy-saving system through human presence detection was being developed and tested using a PIR sensor and data communication using the wireless sensor network approach. Zigbee wireless technology was used to transmit and receive the motion data to indicate any human movement in individual rooms using a centralized air conditioning system. This system works with the automated system, but since the physical switching off system is not touchable in most cases, it is not the focus of this study. Instead, a system was built to only display when an area served by an AHU unit is without users, so the last user can switch off the system manually using the knowledge. With this technology, we can control the use of electricity in an area and reduce unused electricity. Based on a case study in Universiti Kebangsaan Malaysia, with two lecturers' room, it is estimated that the system can save up to RM 680.40 kWh in a year. However, the system still needs to be improved to reduce the cost and maximize the energy saving.