A ventilation device and frame system

摘要

A ventilation device comprises a body 10 with an entry port 14 and an exit port 15, a ventilation passage 13 extending through the body 10 between both ports that allow airflow through the body 10, and a noise attenuation device that reduces noise from airflow from the entry 14 to the exit 15 ports. The noise attenuation device comprises a first array 22 of attenuator tubes on one side of the passage 13 and a second array 23 of attenuator tubes 28 on the other side of the passage 13, with both arrays including tubes 28 of different lengths. Each of the tubes 28 has a mouth 27 that opens to the passage 13 and a central axis 24 that runs in the direction of elongation of the tubes 28. At least some of the tubes 28 in the first array 22 oppose some of the tubes 28 in the second array 23. The central axes 24 of the opposing tubes 28 in the region of their mouths 27 are mutually inclined. The arrangement will reduce the noise due to ventilation flow.