The combination of a natural gas-fired unit combined heat and power station and an H2O/LiBr-absorption-cold engine has been submitted to an Energy-Audit for an examination of the efficiency. The basis was the continously recorded energy status of the power-heat-cold combination over a period of one summer month. The feedback of experiences concerns the operation of the absorption-cold engine. it is proved that its effectiveness can be determined and optimized with the help of three operational temperatures, which can be easily recorded, and an extensive, operationally independent efficiency It is further proved that the utilization of the residual heat and power plant enables a considerable reduction in the primary energy expenditure in comparison to other processes of the generation of cold.