Ranque-Hilsch phenomenon remains as one of the unsolved problems in physics up to the date. Although there are many hipotheses attemping to describe the effect, none of them are experimentally proven. None the less, over past few decades several attemps on analytical description of the phenomenon were underatken. The analytical model allows one to investigate theoretical thermodynamic cycles that involve vortex tube, hence the mathematical description of the process is highly demanded. The present paper focuses on comparison of selected models using experimental data published in the literature. The models are compared using least squares method on achieved temperatures at both cold and hot outlet of the vortex tube. The aim of the comparison is to check the accuarcy of the models for different pressures, temperatures and mediums. The mediums that were selected for the investigation are: air (for its commonness), methan (for natural gas industry) and carbon dioxide (for new HVAC technologies).