A: I wouldn’t because of the louvers
A: Very good
A: Thank you for your question. This listing states that this fan features automatic shutters that open and close in tandem with the operation of the fan.
A: Vibration is cause by improper installation. Please discontinue using the fan and install them properly, vibration can cause the fan motor to be stress and fail. If you need further assistance please contact us at 800-317-1688. We would be happy to assist you.
A: base from the size you provided the required airflow is 3333.3CFM. The 20" fan has 3368CFM.
|Name||3852 CFM Silver Electric Powered Gable Mount Shutter Fan/Vent||3368 CFM Silver Electric Powered Gable Mount Shutter Fan/Vent||3368 CFM 20 in. Silver Aluminum High Speed Gable Mount Shutter Exhaust Fan||4244 CFM Silver Electric Powered Gable Mount Shutter Fan/Vent|
|Features||Automatic Shutter,Corrosion Resistant,Weather Resistant||Automatic Shutter,Corrosion Resistant,Thermostat Controlled,Weather Resistant||Weather Resistant||Automatic Shutter,Corrosion Resistant,Weather Resistant|
|Power Type||Electric Powered||Electric Powered||Electric Powered||Electric Powered|
|Net-Free Area (Sq. In.)||19||21||200||25|
|Drive Type||Direct Drive||Direct Drive||Direct Drive||Direct Drive|
|Rough Opening Width (In.)||19 in||21 in||23.4 in||25 in|
|Mounting Position||Gable Mount||Gable Mount||Gable Mount||Gable Mount|
|View Product||View Product||View Product||View Product|