Exergy analysis and performance of a Ranque-Hilsch Vortex Tube (RHVT) with various nozzle cross-section areas (NCSA = 3 x 3, 4 x 4, 5 x 5 mm(2)) were determined under inlet pressures (P-i) of 260, 300 kPa (absolute) pressurized air. The maximum difference in the temperatures of hot output and cold output streams was obtained for NCSA = 3 x 3 mm(2). The total inlet exergy (Sigma (E) over dot(i)), total outlet exergy (Sigma (E) over dot(o)), total lost exergy (Sigma (E) over dot(Lost)) and exergy efficiency (eta, %) were calculated. It was determined that the exergy efficiency of the system, varied between 1% and 39%, and the highest exergy efficiency was obtained for NCSA = 3 x 3 mm(2). The exergy efficiency strongly depends on the level of P-i, xi and nu(cold)-Variation of the exergy efficiency decreased with decreasing Pi, xi, nu(cold) and the highest and lowest exergy efficiencies were found when the values of P-i, xi, nu(cold) reached maximum and minimum levels, respectively. (C) 2010 Elsevier Ltd and IIR. All rights reserved.