The simplest solution is to install a speed control switch at the wall
switch. The simple ones are resistive and usually provide four settings
(off, low, medium, high speed). If the fan also has a light, then it will
require a second wire from the fan to the wall switch so that each can be
independently controlled.

The additional wall fan speed control will then be wired in series with the
(usually a pull chain switch) speed control provided with the ceiling fan.
You can try various combinations, such as fan speed chain set to high or
possibly medium along with the wall switch to get the "low" speed you
desire.

Most simple combination (fan speed and light dimmer) wall switches can be
found in the electrical department and run US$20-$30 at the home
improvement/hardware stores.

Good luck!

Bob

"D O'Reilly" wrote in message
om...
I have an electric fan in my bedroom when even on its slowest setting
is far too
powerful,can anyone tell me how to adjust the fan with some sort of
device or switch to lower the rpm's,your help would be most
appreciated.

Dave.