Central vacuum units are provided with a canister having a sidewall forming a hollow interior, a vacuum motor disposed within the hollow interior, an exhaust port in fluid communication with the hollow interior, and an acoustic damping pathway. Examples of the acoustic damping pathway can include a plurality of acoustic damping chambers in fluid communication with each other. In addition or alternatively, the acoustic damping pathway can include an inner acoustic damping chamber and an outer acoustic damping chamber. In addition or alternatively, the acoustic damping pathway can form a serpentine passage from the motor to the exhaust port.