Abstract

A dynamic model of a radiant floor heating (RFH) system which predicts the dynamic response of RFH system has been developed. The overall model consists of a boiler, an embedded tube floor slab and building enclosure. The overall model was described by nonlinear differential equations, which were programmed and solved using in MATLAB. The RFH system model has been applied to both a single zone and a multi-zone RFH system. The predicted dynamic responses of the model under several operating conditions were studied. Also, a zonal model of RFH system was developed to study the air temperature distribution in the zone. Three different control strategies for improving the performance of RFH systems were explored. These are: (i) a conventional PI control, (ii) a predictive control and (iii) an optimal control. The simulation results show that PI control strategy is an efficient control strategy for RFH system from the point of view of temperature regulation. The simulation results also show that the predictive PI control maintains zone air temperature close to the set-point better than the conventional PI control. Besides, the predictive PI control strategy saves 10{598}15% energy, compared to the conventional PI control strategy. In addition, the simulation results also show that the optimal PI control strategy could slightly improve both the zone air temperature regulation and energy efficiency, compared to the predictive PI control. Since the predictive control strategy is simple and easy to implement, it is considered as a good candidate strategy for RFH systems.