METHOD OF REDUCING NOISE OF AIR BLOWING DUCT

摘要

A method of reducing the noise of an air blowing duct having an excellent noise reduction property, easily moldable, and suitably used in a clean room. A plate-like or a cylindrical sound absorbing material formed by laminating a skin material formed of dust-free paper on at least one face of an organic fiber nonwoven fabric cloth is installed in the air blowing duct at an approximately right angle to the longitudinal direction of the duct with the surface of the skin material positioned on the upstream side of air flow or on a side where the skin material is brought into contact with the air flow. Where the overall length of the duct is 100 parts, at least one sound absorbing material is installed at a position apart 20 to 50 parts from the upstream end, and the contact area of the skin material surface of the sound absorbing material with air is set to 1/2 to 4/5 of the cross sectional area of the duct, and the overall inside wall surface of the duct is lined with the sound absorbing material to further reduce the noise.