Simulation study of CO2-based outdoor air rate control in public buildings

In this paper, a simulation model was built to study the CO₂-based outdoor air rate control system in public buildings by PID control and fuzzy-PI control method. It is shown that classical PID algorithm can eliminates steady-state error, but the overtune is big and transitional time is long. The PID algorithm only suits for the case of CO₂ concentration changed small. When the CO₂ concentration has big change, fuzzy-PID algorithm can trace the CO₂ concentration, and control the outdoor air rates reasonably. The VAV system of public building employed fuzzy -PID algorithm can obtain a better control performance than that classical PID algorithm.