Experimental study on the operating characteristic of a combined radiant floor and fan coil cooling system

The radiant floor and fan coil cooling (RF-FCC) system has a wide application range in residential and office buildings due to its high thermal comfort and energy efficiency. The studies on RF-FCC systems often focus on increasing the cooling capacity, reducing the energy consumption, and optimizing the control strategies while overlooking variations in radiant floor surface temperature and indoor temperature during system operations. Therefore, this study uses experimental methods to analyze the radiant floor surface and indoor temperature of the RF-FCC system in order to provide a theoretical basis for the application of the RF-FCC systems. The operating characteristics of the RF-FCC system are then determined from the variations of the radiant floor surface temperature during system operation, variations of the radiant floor surface temperature after shutdown, impact of the sudden variations of the indoor load on the indoor temperature, and impacts of different outdoor weather conditions on the indoor temperature. The obtained results show that the radiant floor surface temperature stabilizes at approximately 23 degrees C under different weather conditions. After shutdown, the variation of the radiant floor temperature follows the first-order exponential function growth law. The indoor load step change only slightly affects the temperature of each indoor wall surface, while indoor load step change exerts a minimal impact on the radiant floor surface temperature.