Eli5 does ceiling fans have dust stick and not fall off?


I work as engineer in hvac and a teacher once taught me the reason behind this question but I can’t seem to find that actually correct and full answer of this question so hopefully one of you can help me out. Thanks.
Why does a ceiling fan, and other fans for that matter I guess, collect dust toward the tip of the blade it spins? I know bc it comes in contact etc but why won’t it fall off when being turned on fast mode etc ?

In: 0

Most dust particles have an electrostatic charge, and so these charged particles adhere very strongly to the fan blades (which also have an electrostatic charge). The bond created between the opposite charges is too strong for the wind resistance alone to knock them off the blade, requiring the blades to be cleaned. Water easily neutralizes the electrostatic charges of the dust (or, more accurately, compliments the electrostatic charge better than the fan blade), encouraging the dust to detach from the blade and remove with the damp cloth you’re cleaning with.

There’s always an area where the airflow splits between each side of the blade, where there’s actually no wind at all. Also, hairs and fibers that hit just right get draped across the blade, experiencing the same drag in both directions. This happens with cait hair at home. Very small dust particles also sometimes get stuck under the boundary layer of slower-moving air which forms when air flows across any surface. And when the first dust has gotten stuck, it can grab onto other dust flowing by.


Okay. Imagine a magnet. It has a positive and a negative side. When you take another magnet, the positive and negative sites stick together.

Most dust contains positive iones, which makes the dust the positive side of the magnet.
If the fan blades are loaded positive (contain more protons then electrones) the fan is the positive side of the magnet.

The dust sticks to the fan blades until the fan spins so fast that air resistance is greater then the magnetic force