The relative humidity control

This research studied on the relative humidity controller by fuzzy logic method. The system consists of the evaporating coils laid inside the duct which has square shape cross section area and the relative humidity at the duct output is considered. The relative humidity set point changing and the air flow rate are parameters of this study. The relative humidity process variable is detected by the relative humidity sensor and it need to be processing by the personal computer, Visual Basic 6.0 language is use for build the command of fuzzy logic control and will be operated under the window 98 system. The results show that the relative humidity controller can be controlled the relative humidity in the process satisfaction. It has the steady state error about ± 3 %RH and has the rise time to the set point within 3 minutes at the relative humidity rang of 60–80 %RH and the air flow rate 5.43–8.5 m/s.