A user called Grantig on computerbase.de created the tool Notebook FanControl. It is written in C# and uses WCF for communication with a backend service. Using JustDecompile and the information from the config I managed to build my own front-end.

Image courtesy of bplanet / FreeDigitalPhotos.net

The Fancontrol client uses a DispatcherTimer for interval updates. A DispatcherTimer is close related to WPF and needs some extra work for unittesting and other non-WPF programs. So I’m using polling.

// simplified code
var model = new NbfcServiceClient.ViewModels.MainWindowViewModel();
model.PropertyChanged += (s, e) => 
    Console.WriteLine(model.CpuTemperature);
var client = new NbfcServiceClient.FanControlClient(model, 10);
client.StartFanControl();

// polling (done recursive)
Task.Factory.StartNew(() => {
    client.UpdateViewModel();
    Thread.Sleep(10000);
};

References

How to Test a Class Which Uses DispatcherTimer by Josh Smith.
My sources on Github