Enhancement of cooling capacity through open-type installation of cooling radiant ceiling panel systems

Cooling radiant ceiling panel (CRCP) systems have been increasingly applied to modern buildings, owing to high thermal comfort, energy-saving potential, and integration with building design. Currently, the cooling capacity of CRCP is generally evaluated for the closed-type CRCP, wherein the overall ceiling surface is covered with ceiling panels. However, there have been few previous studies on the evaluation of the cooling capacity for open-type CRCP, which are installed with openings (void areas) between adjacent ceiling panels. This study was conducted to verify the hypothesis that the open-type CRCP can enhance cooling capacity by utilizing the cooled plenum air moving through the opening. If the plenum air is cooled by the upper surface of ceiling panels and descends to the conditioned space, it can contribute to increasing the convective heat transfer and cooling capacity. A simulation model for open-type CRCP was developed and validated against the mock-up experiment. Using the simulation model, the cooling capacity of the open-type CRCP was evaluated with respect to the opening area and panel layout. The results showed that the open-type CRCP could provide 54–80% (average 64%) higher nominal cooling capacity than conventional closed-type CRCP. The enhanced cooling capacity may lead to reduction in construction costs and energy consumption, because panel installation area could be reduced and the water temperature can be increased to provide the required cooling capacity. The results of this study would be able to offer fundamental data about cooling capacity of open-type CRCP.