can anyone explaine me how the fan works
when do I have to increase or decrease the number and why
I don't have a clue
thankx
More fan > more details, less adhesion.
Usually you need more fan on small and/or detailed models.
On a coin size I would use 100% fan.
I can confirm what Venosa said and would add, that I would suggest to use less fan when printing large (flat) objects to decrease speed of shrinking whats the main reason for warping.