Didactic models are applied for the purpose of educating on particular systems in order to show the principle of operation of a system in a simple and visually acceptable way. The basic characteristics of the model are clearly visible all the functional elements of the system and components for displaying the situation in characteristic places. The task of this work is to design and construct a didactic model of a refrigeration unit. Given the breadth of the refrigeration field, this paper will deal with the basic refrigeration cycle on which refrigerator operation is based. The operation of a single-stage cooling cycle will be illustrated using diagrams and working component calculations. When designing, modelling and calculating the model, it is necessary to find the optimal solution with respect to thermodynamic, structural and operational requirements.