In this paper, an MQTT based protocol is designed and implemented for control, management and monitoring of HVAC in a cloud platform in real time. The MQTT protocol is a two-way messaging protocol, and has the generality, flexibility, light weighted, quickness with reliability and security. In the implemented system, performance and reliability of the communication protocol is considered for data acquisition and control between the CCU and the cloud server. Control and monitoring for the cloud server is performed in real time in conjunction with CCU and the MQTT server.키워드 : MQTT, 공조제어, 클라우드, 실시간 제어 및 모니터링