Controlling a shaded pole fan via light dimmer switch? Which among these two fans are better for cooling?
Can the speed of these fans be controlled via a simple light dimmer or the need a specific motor speed controller (maybe a triac controller)? Also if I used a light dimmer and wanted a slower speed to reduce noise, will the motor stall after a certain point and cause it to overheat?


A triac controller is a type of AC voltage controller. Other motor controllers and light dimmers may have a DC output. Any triac controller with a high enough current or power rating will probably be ok to the extent that the fan will probably not cause the controller to fail.

The controller waveform and voltage reduction will tend to cause additional heating in the motor. However the nature of a fan load is such that the power to the motor will be reduced by reducing the speed. That will tend to offset the effect of the waveform and voltage reduction. However the fan's air flow helps to cool the motor. Since reducing the speed reduces the air flow, that is another factor that would tend to make the motor get too hot. You should run the motor for an hour or so directly connected to AC power and see what the normal operating temperature is. Then try the speed controller and see what the temperature is with that.

At some point in speed reduction, the motor speed might not stay at a steady speed. It may slow down drastically or stop with just a little further reduction in voltage. That greatly increases the risk of the motor overheating.

This setup will not conform to UL standards unless you can find fan manufacturer literature and speed controller literature that says the two products are listed by UL or some other nationally recognized testing laboratory as suitable to be used as you will be using them. The same is true of your flask heating setup. You will need to evaluate the risk and decide what you want to do. It is probably not a good idea to turn your back on the setup until you have watched it for quit a while. It may not be a good idea to ever leave it unattended.