WhisperFresh Select™ is the ultimate supply air fan. Built-in Pick-A-Flow™ airflow selector switch allows you to select your required airflow (50 to 150 cfm). Features an ECM Motor with SmartFlow™® technology for cfm output to achieve precision whole-house supply ventilation. WhisperFresh Select can be used to comply with the latest codes and standards including ASHRAE 62.2, LEED and CA Title 24.