Study on Control Performance of HVAC System or Interior Zone and Perimeter Zone in Office Building; Estimation of Optimal PI Tuning in Cooling Operation

Abstract

In office buildings there are generally two HVAC systems installed, one in the perimeter zone (PZ) and one in the interior zone (IZ), and the temperatures of each zone are independently controlled. In the present paper, in order to the solve problem of not being able to satisfy the requirements of room temperature control during the cooling period in summer, an optimal PID parameter (O-PI) is selected through simulation of its two feedback control systems with mutual influence using the models identified with the experimental data. The step response characteristics of the system with optimal parameters compared to those with the parameters selected by the Ziegler-Nichols Method (ZNM-PI) that are generally used for PID parameter tuning on site. The result shows O-PI improved control performance, and the difference between O-PI and ZNM-PI can be used to readjust ZNM-PI selected on site.