Patent ID: 6589112
Filing Date: 2003-07-08
Classification: F24F,Y10S

Abstract:
A ventilation duct, comprising:a frame; at least one of inner sound absorbing member secured to the frame within a first plane, the inner sound absorbing members defining a first outer surface and a first longitudinal cavity, the first longitudinal cavity filled with a sound absorbing material, and a first plurality of sound transmission passages in the first outer surface to direct sound into the first longitudinal cavity for sound abatement by the sound absorbing material; at least one outer sound absorbing member secured to the frame within a second plane with the first plane being substantially parallel to the second plane and the outer members secured in the frame such that at least a portion of each outer members overlaps with at least of portion of an inner member to inhibit the transmission of sound, and the outer sound absorbing members defining a second longitudinal cavity, the second longitudinal cavity filled with the sound absorbing material, and a second plurality of sound transmission passages in a second outer surface to direct sound into the second longitudinal cavity for sound abatement by the sound absorbing material with the second plurality of sound transmission passages on an inner region of the outer sound absorbing members, wherein the inner sound absorbing member and the outer sound absorbing member have opposed apexes.