Patent ID: 8641494

Claim:
A ventilation device comprising a body having first and second ports, a ventilation passage extending through the body between the ports to allow airflow through the body, a noise attenuation device arranged to attenuate noise transmission through the passage from the first to the second port, the noise attenuation device comprising first and second arrays of attenuator tubes, the first array of attenuator tubes extending from a first wall of the body, and the second array of attenuator tubes extending from a second wall of the body, wherein the first and second arrays of attenuator tubes are disposed on respective opposite sides of the passage, the tubes each having a mouth that opens to the passage and a central axis extending from the center of the mouth in the direction of the elongation of that tube, wherein the tubes in the first array oppose the tubes in the second array with the central axes of the opposing tubes at the region of their mouths being mutually inclined at a substantially right angle and wherein the first and second walls are at substantially right angles.