Abstract
Radiant heating/cooling systems are expected to be more comfortable and superior energysaving systems than convective air-conditioning systems generally used. There are many studies on radiant cooling systems, but they have seldom been put to practical use, because of the condensation problem in Japan. The objective of this study is to investigate thermal comfort in particular, including the effects of humidity (45%rh, 65%rh, 85%rh) and air movement (0.1m/s: constant, on/off; 0.1〜0.3 m/s: random change), by means of subjective experiments conducted on a radiant ceiling cooling system. The experiments are performed with radiant cooling panels in a climate chamber. The subjects sat on a chair under the radiant cooling panels, and they voted on thermal sensation and thermal comfort. The following results were obtained. With the radiant cooling system, the influence of humidity and air movement on thermal sensation votes for the whole body was evaluated by SET^* within one scale difference on the thermal sensation vote (7 scale) in the above experimental conditions. Air movement with the radiant cooling system was expected to have one scale cooler effect than the thermal sensation vote evaluated by SET^*. In addition, a small amount of air movement was expected to improve the comfortable sensation votes with the radiant cooling.
