Under the modernization is understood not simply replacing outdated equipment and selection of a commercially available equipment approaching the maximum in their characteristics to the optimal solution for the refrigerating machine. On the basis of the thermal and economic optimization the algorithm has been developed for the modernization of refrigeration equipment the adequacy of which is confirmed by a number of physical experiments under the conditions of an industrial operation of the refrigerating machines. It has no limitations associated with the scheme and structural characteristics of the object, by the parameters of the thermodynamic cycle and operating features. Taking into account the thermodynamic and cost parameters it was determined the best variant of the modernized scheme of the refrigerating machine that provides at least the current costs.