#/etc/thinkfan.conf:
hwmon /sys/devices/virtual/hwmon/hwmon0/temp1_input
tp_fan /proc/acpi/ibm/fan

(0,  0, 25)
(1,  20, 30)
(2,  25, 31)
(3,  30, 36)
(4,  35, 41)
(5,  40, 47)
(6,  46, 50)
(7,  49, 56)
(126,  55, 32767)


#/etc/systemd/system/thinkfan.service
[Unit]
Description=simple and lightweight fan control program
After=syslog.target

[Service]
Type=forking
ExecStart=/usr/local/sbin/thinkfan
PIDFile=/var/run/thinkfan.pid
ExecReload=/bin/kill -HUP $MAINPID

[Install]
WantedBy=multi-user.target


#INSTALL (as root)
echo "options thinkpad_acpi fan_control=1" >> /etc/modprobe.d/thinkpad.conf
reboot
apt install lm-sensors cmake-curses-gui libyaml-cpp-dev libboost-all-dev
wget https://github.com/vmatare/thinkfan/archive/0.9.3.tar.gz
tar xzvf 0.9.3.tar.gz
cd thinkfan-0.9.3
mkdir build; cd build
cmake -D CMAKE_BUILD_TYPE:STRING=Debug ..
make
cp thinkfan /usr/local/sbin
sudo systemctl enable thinkfan.service
sudo systemctl start thinkfan.service