Experimental investigation on the heat transfer performance and water condensation phenomenon of radiant cooling panels

Radiant cooling system is a promising technique, which is suitable for independent control processes of temperature and humidity. The two main benefits of radiant cooling systems include the potential to save energy and improvement of indoor thermal comfort. However, both the poor heat transfer performance and condensation below dew point temperature restrict the widespread utilization in the residential buildings especially in humid environment. This research was focused on comprehending detailed performance of the radiant cooling panel when it used as an air conditioning system. Three radiant cooling panels with the area of 0.16 m(2) were prepared for investigation and a constant temperature and humidity environment chamber employed to simulate the different indoor thermal environments. The heat transfer performance and moisture condensation phenomenon of the radiant cooling panels were investigated. The results showed that the flow state of chilled water had the biggest influence on the heat transfer performance of the radiant cooling panels. The temperature difference between chilled water and the ambient was also observed to significantly affect the performance. Condensation of moisture on the radiant cooling panels was noted to increase the heat transfer quantity, but posed a challenge in using of the radiant cooling panel. Taking the performance of heat transfer and moisture condensation into consideration, the gypsum radiant cooling panel showed the best performance as compared to the metal radiant cooling panel and pure tube panel. The radiant cooling panels can work more efficiently especially when proper control strategies are employed to avoid condensation. (C) 2013 Elsevier Ltd. All rights reserved.