(Source: CIBSE Journal)
The air duct velocity — also known as air flow velocity — is a measurement of the air that moves through your HVAC system’s air supply and return grilles. This can be measured in either feet- -per-minute (FPM) or meters-per-second (m/s).
Your air duct velocity should be kept within set limits in order to lower noise and excessive friction loss. Both are essential for ensuring occupant comfort.