The heat decoupling has repercussions on the irreversible course in the system considered. When knowing these repercussions, the evaluation of the coupling product ＇＇heat＇＇ become clear. Furthermore, a statement on the quality of the coupling in dependence on the selected circuitry and the process parameters is possible. Under this aspect, the combined heat and power porcess (KWK) at condensation units is analysed. We see that the combined heat and power process, exceeds in general the quality of an ideal heat pump, as via decoupling the irreversibility is reduced. The outstanding importance of the combined heat and power process is emphasized.