If I turn my fan on and 100% of the electricity is converted to heat, where does the kinetic energy of moving fan blades come from? Even the Trump administration cannot just repeal the law of conservation of energy.
After removing power even that small amount ends up as heat through friction ( both in the bearing but mostly in the air turbulence). And the blades end up in the same zero energy state: sitting still.
So it is correct that a 100% "end up" as heat
We do know what that air does eventually. Given no further inputs of energy, it swirls around generating friction, raising its temperature (heat!) as the currents slow down to nearly nothing.