Ceiling fans are nothing but fun! Take forever to install, then you get a problem....
Sounds like either this one is defective, or a swtich controlling it is. Several things could be causing this:
1. Motor poorly made - quality of fans has gone down quite a bit in the last 10 years - motors are made more cheaply.
2. Wall mounted speed control - if the fan has a speed control in place of the switch on the wall, it may be causing the hum on the lower settings. Try putting a regular on-off switch back in, and see if the noise goes away (under the assumption an electrician is there, or you have electrical experience).
3. Capacitor in the switch housing - there are usually one or two large capacitors in the swtich housing of the fan to suppress 60 cycle noise. One of them may be defective, or not of sufficient size to handle the noise.
4. Harmonics bad in that room - try swapping fans - put one of the good ones in place of the bad one. If the noise is still there, it could be that the ceiling joists are just magnifying the normal hum from the motor.
Any way you slice it, this is a bit of a pain to resolve. Best of luck and let me know how it goes -
Regards,
Tim D.
http://www.electricalrepairlinks.com
Tim, July 2006
