Mitigation systems have several potential noise sources; the motor, the exhaust, and vibration/turbulence in the piping. Most of these can usually be minimized by proper system design and location. Fan and exhaust noise are to some degree a function of which fan is the right one for the job, and how much air the fan is moving. Noisy fans can be insulated or covered. Mufflers can be installed to significantly reduce exhaust noise. Pipe vibration can usually be dampened.