Herwig, HeinzHeinzHerwig2019-07-172019-07-172018International Heat Transfer Conference (IHTC 2018)http://hdl.handle.net/11420/2959In order to teach heat transfer systematically and with a clear physical background it is recommended not to ignore entropy as a fundamental quantity. Heat transfer processes are characterized by introducing the so-called entropic potential of the transferred energy and an assessment number is based on this new quantity. Prior to these considerations the concept of a thermally active layer is introduced by which various heat transfer situations can be uniquely qualified with respect to their general performance. And: It is suggested to categorize heat transfer situations quite generally as either conduction based or radiation based heat transfer processes. Three examples illustrate all these different aspects.enAllgemeines, WissenschaftConference PaperOther