Temperature

If you notice your CPU fan is always running on a Debian based UBO, try the following steps:

$ sudo apt-get install lm-sensors fancontrol
$ sudo sensors-detect # choose YES to everything, including at the end to have it auto-add to /etc/modules
$ sudo service module-init-tools restart 
$ sensors

This will show you your sensors

$ sudo pwmconfig

Go through this setup to control your fan to only go on when the temperature hits a certain threshold.