The present study is intended to discuss the thermal performance improvement of a vortex tube using a computational fluid dynamics approach. Different working fluids are taken for comparison in the present investigation, i.e., air, nitrogen, CO₂, and argon with different insulating materials for a compressible, 3-D, axisymmetric, turbulent, and steady-state flow vortex tube. In the present investigation. For numerical study, the ANSYS17.1 FLUENT application was utilised with a k-ε turbulent standard model with varying mass fractions and pressure at the inlet, and findings were validated by experimental outcomes. The study concludes that taking N₂ as a working fluid and polyurethane as insulating material in the vortex tube, there is an increment of 10.345% in the vortex tube cooling performance as compared to the vortex tube having no insulation and using air as a working fluid.