There are many considerations when evaluating noise levels in any given space. Air distribution is just one of those factors.
FabricAir ducts are designed to have low internal velocities and if needed can also have low velocities in the occupied zone. A typical FabricAir system is designed to have an inlet velocity of between 6-8 m/s [1200-1600 FPM]. At these low velocities the noise generated by the air stream is kept to a minimum allowing for very low NC levels. There are applications that require low velocities in the occupied zone, such as office settings or refrigerated facilities with employees, to achieve full occupant comfort. FabricAir can achieve this by varying the size, spacing, and number of orifices, nozzles, etc. at the manufacturing facility so that the duct is ready to install on-site without the need for balancing.