Effect of inlet water temperature and flow rate on cooling efficiency of a radiant ceiling system in Taiwan

This study is to test the cooling capacity of radiant ceiling system established in a typical office. The dimension of the test chamber is 10 (Length), 7.6 (Width), and 3.85 meter (Height). The objective of this research is to figure out different supplying water temperature accompanies flow rate embedded in radiant ceiling panels with a water circulatory system, which influences the cooling and energy efficiency of the test room. The heat transfer principles of radiation and natural convection are used to remove the sensible heat from the studied office without using any additional mechanical ventilation system to provide forced convection. We adopt five conditions of inlet water temperature 16, 18, 20, 22, and 24°C with water flow rate 40, 60, 80, and 100 LPM (liter per minute) to test the vertical temperature gradient inside the room and discuss the interactive effects between the parameters within one hour. The experimental values reveal that the better operative efficiency occurs as the inlet water temperature is 18°C and flow rate is 100 LPM without condensation water on the radiant panel surface. The obtained results also indicate the radiative heat flux of radiant ceiling system using in the subtropical region in Taiwan.