A practical application of fuzzy control for an air-conditioning system

Abstract A practical application is given of a fuzzy control system for an air-conditioning system, and the results of simulation and practical use are presented. Air-handling units are widely used for central air-conditioning systems. The control system has two controlled variables (temperature and humidity) and three final controlling elements (cooling, heating, and humidifying valves). In order to achieve high efficiency and economical control, the two kinds of requests (temperature and humidity requests) must be adequately allotted to the three final controlling elements. The fuzzy control system infers two kinds of requests and the allotment. The results of simulation and practical use show that this design is effective. In the fuzzy control system, the hardware of a fuzzy inference engine is used. Using this hardware it will be possible to make the necessary inference in less time than is needed with only the software system. This paper introduces the hardware system.