This section introduces the concept of feedback and the control loop. It describes the basic control modes used in HVAC controls, including:
— simple on/off control
— proportional, integral and derivative control
— optimisers and compensators
— intelligent controls.
Issues of stability are dealt with and methods of tuning control loops for the best combination of response speed and stability are given. The section goes on to discuss advances in adaptive controls, which learn by experience how to optimise operation of a controller.