An experimental investigation of a Ranque-Hilsch vortex tube has been performed. The investigation focuses on the effects that pressure magnitude, pressure drop and pressure ratio have on the temperature drop between the inlet and the cold outlet. The Ranque-Hilsch vortex tube used in the experiments was designed through consideration of a large body of experimental data consolidated from existing literature. Experiments are conducted for cases of constant cold exit pressure (0.31 [MPa]), constant pressure drop between the inlet and cold exit (0.31 [MPa]), and constant pressure ratio between the inlet and cold outlet (2.0). From the experimental data collected, the temperature drop was found to be best correlated to the ratio of the inlet and cold outlet pressures, suggesting that the process could be characterized as polytropic. Results for each case were reported in terms of recovery temperature and static temperature to illustrate the importance of interpreting the dynamic component of temperature in the results. The reported results show that for a pressure ratio of 2.0, the maximum recovery temperature drop is 13.96 [K], whereas the corresponding static temperature drop is 12.25 [K].