I can't believe someone has brought up the subject of desk fans and quality of their silent running.
I just serviced two fans the other day which mainly involved cleaning the dust off the propellers. It's amazing how much it improves air flow performance. The dust clearly affects aerodynamics of the fan ears.
I have a third oscillating one with three speed controls, inherited from my late paternal grandmother that she purchased new about 1979 and it was going like clockwork until a few weeks ago when sparks started crackling out of the buttons on the base. It was beautifully silent and blew a gale in your face, so much so, I mostly had it on number one setting.
Upon examination, I discovered this (now defunct) Waltons store branded Celestial fan was made in Japan! No wonder it lasted so long and was so solid looking. I want to save it and get it going again. I wonder who could repair it?