PI auto-tuning and performance assessment in HVAC systems

Proportional-integral control with default tuning numbers is often used in Heating Ventilation and Air Conditioning (HVAC) systems resulting in suboptimal control performance. A well-known relay based auto-tuning method is modified for a class of HVAC systems and a novel, corresponding performance criteria developed for evaluating resulting control performance. The developed methodology, including modified auto-tuning method and performance criteria assessment, has been successfully demonstrated in a field trial for a Fan Coil Unit (FCU) in an HVAC system.