| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a ceiling for reducing the impact noises of a floor while preventing dew condensation without excessively increasing the thickness of a ceiling portion. <P>SOLUTION: This on-ceiling-placed coals include coals which have major diameters of 15mm or less after carbonized, which account for 80 wt% or more of total coals, and which have a bulk density of 0.12 g/cm<SP>3</SP>or more. The bulk density is greater, a placement thickness is relatively smaller and the rate of short or small coals is higher to improve the diffusion efficiency of noises, while a specific surface area is larger to improve moisture control performance. The rate of the short or small coals is higher to make coals in layers, prevent the entry (blow) of outside air directly into a room and secure ventilation while maintaining air tightness. Thus, the ceiling reduces the impact noises of the floor while preventing dew condensation without excessively increasing the thickness of the ceiling portion. The ceiling is constructed using the preset thickness of coals for improved heat insulating property and heat storage property. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
