Relatively small fan + high speed to move air = course it sounds ..
If you want to move a lot of air at low noise levels may be acquiring a large ceiling fan.
The leaves sounds when they rotate and push air like any other fan, but the engine does not seem to emit much sound. Fan noise is the frequency which I interpret as it keeps stable speed. It cools herself well, despite hours at maximum speed engine casing feels cool.
Very sturdy, long cord and looks good for being a fan.
Good, stable but ... sounds like crazy! Can not watch TV in the same room.