Gain-scheduling is possibly the most widely used nonlinear control design technique in industry. However, guaranteeing the stability of the resulting closed loop system can be extremely challenging. This paper discusses the application of gain-scheduled control approach using the Youla parameterization to an air conditioning system. This framework is shown to be a generalization of the more common Local Controller Network approach, while exposing elements of design freedom that can be exploited to improve stability. Analysis techniques are presented for determining the practical stability on the gain scheduled closed loop system despite arbitrarily fast changes in the scheduling parameter. Finally, the gain scheduled control approach is experimentally validated on an air conditioning system.