With /sys/class/fan you can switch driver to manual mode and set fan level.
echo 0 > /sys/class/fan/mode – manual mode
echo 0 > /sys/class/fan/level – fan off
echo 1 > /sys/class/fan/level – fan low
echo 2 > /sys/class/fan/level – fan normal
echo 3 > /sys/class/fan/level – fan high