I have been using Macs Fan Control on my Intel Mini for the last couple years off and on. When it is running the metal case of the Mini is cool to the touch but the fan is loud. Turn off the application and the case top runs hot as heck even at idle but is dead quiet. I have read that this is by design and AFAICT it has not caused any issues for me.
As this is now just a backup device these days it really is not an issue for me so I shut off the control app and let the fans go on auto.