TO-92 not getting hot enough
The 0.83 W is the power going into the fan, not the transistor.

The power dissipated by the transistor is essentially the same current value, but multiplied by the voltage from C to E, which is probably only on the order of 200-300&nbsp;mV when saturated. That would make the transistor dissipation something like 15-20&nbsp;mW, which will give you a rise in case temperature of only a few degrees at most.