Evaluating the dynamic heat efficiency of intermittent heating terminals using energy, exergy and entransy-based methods

Intermittent heating is gaining popularity due to its energy-saving benefits and suitability for partial-time and partial-space heating. With the availability of different types of heating terminals, it is crucial to evaluate their heating performance. Although researchers have developed various evaluation indexes, there is still a lack of a comprehensive analysis method that encompasses the inherent properties of terminals, including thermal response rate and heat transfer ability. In this study, the energy, exergy, and entransy-based methods were employed to calculate the heat performance of a radiant floor and a fan coil heating system in a test platform. The results demonstrated that the dynamic exergy and entransy efficiency indexes effectively captured the thermal response and heat transfer ability of the heating terminals, with a difference of approximately 3% between their values. Furthermore, the exergy and entransy-based methods exhibited similar potentials for heat transfer optimization in the case of the radiant floor, while displaying disparities for the fan coil. The heat performance of the fan coil was significantly superior to that of the radiant floor system in the context of intermittent heating. This study serves as a valuable theoretical reference for the selection and optimization of heating terminals for intermittent heating applications.