Abstract: Control methodologies could achieve better comfort conditions of heating, ventilating and air conditioning (HVAC) systems, however, the application of classical controllers is unsatisfactory as HVAC systems are non-linear and the control variables such as temperature and relative humidity (RH) inside the thermal zone are coupled. The objective of this study is to implement and simulate adaptive control for decoupled HVAC to control temperature and RH. A non-linear decoupling algorithm is used to decouple the HVAC system and an adaptive controller is applied to control the temperature and RH, and improve the transient response of system. The simulation results show that the adaptive controller performance is superior, as compared with classical PID controller. In addition, the steady state set points for temperature and RH are better reached in a shorter period of time.