Electric Motor connected with lights dimmer for speed control? = FAIL solution

[Kiriakos GR]

Electric Motor connected with dimmer becomes a sound speaker of High pitched noise.

Summer heat this is too much in Greece starting from hart of June and up to 10 of September.
At home I have one large (old school) Mitsubishi electric fan,  it is great to keep you cool at midday time but at nights it is impossible for you to sleep near it.
This is desktop fan, full metal, blades diameter close to 60 centimeters.

And I did use as experiment one lights dimmer (by foot adjust type / sliding potentiometer), I connected to it one female power socket ( for cables extension), and I thought that I am good to go.     

By starting using it and adjusting the speed, the motor  this become instantly a sound speaker of High pitched noise 
My plan to slow down the electric fan rpm this was successful,  but this  High pitched noise it is something that no human can tolerate.

Light bulbs can tolerate using dirty energy but regular electric motors are not prepared for a such conditions.


In conclusion: 
Noiseless speed control for Mains volts this is a job for variac transformer and of nothing else. 

http://www.ittsb.eu/forum/index.php?topic=1240.msg3092#msg3092