PID controller tuning and implementation aspects for building thermal control

The control of the indoor environmental parameters of buildings is an open problem with many practical difficulties which stem from the non-linear, multivariable nature of the building models. This paper presents the tuning process of a conventional PID controller for the thermal comfort control application, in buildings utilizing fieldbus systems. The PID controller has been chosen taking into account its widespread deployment and its attractive features like low computational cost and simplicity of implementation. On the contrary, there is no standard methodology for the extraction of its parameters. Therefore, empirical methods should be utilized along with trial and error techniques on the target application. The design procedure is illustrated and there is special focus regarding the practical aspects of the implementation on a laboratory installation. Finally, the results of the monitored and computed variables of the experimental procedure are presented along with relevant conclusions and discussion.