Hey DaDuck..

Have you looked up any methods of noise control for fans? Lots of stuff... One method im going to apply in my current grow is hanging the fan from the ceiling with chains so that the vibrations transfered are minimized. Because I also have neighbors on the other side of a wall in a townhouse.

You can also build a box and install the fan inside the box and hang the box. Even put rubber matting on the inside of the box to kill sound waves!