Switching off fans - lowering power consumption KDE - Assus TUF gaming laptop

The fans of my laptop are rattling very loud when mains powered.
When on battery power the fans don’t run, so no disturbing loud noise either.

I suppose the laptop lowers power consumption when on battery, and at that moment, there is no need for the fans to start spinning.
Is there a way to have the same behavior when mains powered, so I can get rid of the irritating rattling fan noise ?
I looked in KDE power settings, but I don’t see a setting to cut power consumption or to stop the fans.

Have you checked your BIOS settings already?

Asus TUF series typically uses cheapo thermal paste, replace with either Thermal Grizzly Kryonaut or Honeywell PTM7950. A good and bad thermal paste could be the difference between your fans crying out loud and whispering during full load. At least it is on my ROG.