Attenuated Ducts
Are stretches of straight duct or figure, which act as attenuators of noise in air ducts. They are interspersed on the same line section and respecting the air flow and act as acoustic sound-absorbents. Their construction is basically a tube lined inside with mineral wool protected by a perforated plate to ensure the passage of air at speeds above 15 m / sec without detachment of materials.
Ideal for use as silencers support. They are manufactured in galvanized steel sheet 1.2 mm thick and 0.8 mm inside (perforated plate); the sound absorbing chamber can be 50 mm or 100 mm, depending on the degree of attenuation required. Ideal for medium and high frequencies attenuate. Its length will depend on the degree of attenuation we want to get.