Experimental study on control performance comparison between model predictive control and proportion-integral-derivative control for radiant ceiling cooling integrated with underfloor ventilation system

Radiant ceiling cooling integrated with underfloor ventilation (RCCUV) system has energy-saving potential in buildings. However, control problem results in its energy-saving effect lower than expected and restricts its application. Conventional control is inadequate due to its poor performance, control lag and low economy, etc. The objectives of this study are to: (1) develop advanced model predictive control (MPC) controller of RCCUV system; and (2) experimentally discuss MPC controller performance compared with conventional proportional-integral-derivative (PID) controller performance. The experimental results indicated that under experimental step setpoint variations, the adjusting time of controlled variables using MPC controller was less than that of using PID controller. The time to reach recommended thermal comfort range using MPC controller was 3 min, and was 13 min using PID controller under experimental step setpoint variations. Meanwhile, MPC controller reduced energy consumption of RCCUV system by 13.2% compared with PID controller during 2 h of experimental period. Thus, control performance of MPC controller is superior to that of PID controller in every aspect. The study provides an advanced superior MPC controller for RCCUV system.