| 摘要 |
PURPOSE:To simplify a duct forming construction and to prevent vapor condensation by winding a nonflammable or flame retardant sheet on an outer periphery of an air duct body, and forming a layer impregnated with inorganic formable silicate on the sheet. CONSTITUTION:An air duct 1 is wound with a nonflammable or flame retardant sheet 3 impregnated with inorganic foamable silicate on an air duct body 2 such as a spiral steel tube, etc. Since the silicate has excellent heat insulation as a heat insulator and moisture absorption/radiation properties, it is effective to prevent vapor condensation. Adherence of the silicate to the sheet 3 is excellent, and the sheet 3 can be wound in close contact on the body 2. Further, the duct 2 obtained by winding the sheet 3 previously impregnated with the silicate in a manufacturing factory on the body 2 can be supplied to a construction site to simplify a duct construction. |
