Experimental investigation on the cooling performance of a novel grooved radiant panel filled with heat transfer liquid

Radiant ceiling cooling system is considered as a promising technique, which has huge potential to energy saving and suits for independent control of temperature and humidity. In this paper, a novel radiant panel was developed for cooling, which consists of top flat plate, bottom groove plate, and heat transfer liquid filling in the gap of two plates. A series of tests were conducted and results suggested that the cooling capacity of this radiant panel could reach at 93.5 W/m² to 153.3 W/m² in test condition, which was higher 18%～25% than that of traditional metal radiant panels. Besides, the maximum temperature difference on the surface of the novel radiant panel was <2.9 ℃ which is smaller than traditional one that is designed as cold-water tubes touching radiant plate directly without filled liquid. These advantages indicate that the radiant panel is suitable for hot and humid environment. The vertical temperature gradient of indoor air within staff activity area was 2.31–2.89 ℃ /m, meeting the requirements of ISO 7730. Moreover, the cooling performance of radiant panel can be changed when filled with different kinds of liquids, so that the radiant panel can be applied in different occasions and suitable for using in series.