An Overview of Proportional plus Integral plus Derivative Control and Suggestions for Its Successful Application and Implementation

PID control loops are becoming quite common in the commercial, institutional, and industrial HVAC industry. Proper application and tuning of this control algorithm can bring many efficiency and performance benefits with it. However, improper application and tuning is often the root cause behind many commissioning problems. This paper will discuss PID history and theory and why it offers certain advantages from a precision and energy conservation standpoint. It will also look at when the algorithm should and should not be applied. Finally, it will look at how to set up, verify and address control loop tuning issues based on field experience and the work of David St. Clair