Reviewing two simple methods of calculating the length of adiabatic capillary tubes.

Capillary tubes are installed in hundreds of millions of household freezers and refrigerators around the world. Even though these devices are produced in large numbers there seems to be no method which is generally accepted for calculating the capillary tube length for a given application. It is of interest to review and compare different methods to calculate the capillary tubes. In this investigation an easy-to-use but fairly accurate method, suitable for hand calculations, for calculating adiabatic capillary tube lengths have been sought. At the end, two correlations from the literature were compared to each other and to experimental data.