Fans are supposed to be managed by ACPI, which allows the kernel to cooperate with the bios to monitor temperature and adjust the fan speed automatically using bios provided rules. Unfortunately, I have yet to see a single bios vendor actually comply with the standard. You might look in /sys/class/thermal and see if there are any fans that show up under there and if they can have their settings changed. Generally the bios ACPI tables don't provide the fan interfaces and just leave it up to a hardware controller to manage.
Many of these hardware controllers can be detected by the lm-sensors package. You run
sensors-detect and it will probe for known controllers and can configure the correct driver to be loaded to manipulate it. This often results in
sensors being able to report various temperature and voltage readings, and the
fancontrol script ( packaged separately in Debian/Ubuntu ) can be configured to manipulate the fan speed in response to the temperature readings.
Many of these modules require you to add
acpi_enforce_resources=lax to the kernel command line to load.