Abstract: In this study, results of thermodynamically analysis were tested and compared, implementing the vacuum cooling of lettuce. According to the findings of the trial and results of the thermodynamically analysis, it is possible to determine the weight loss within an error of 2.12%, close to the other parameters to be used in the design of vacuum precooling system, such as temperature, pressure, enthalpy and entropy on specified points using the mathematical model prepared from thermodynamically equations. Moreover, the fact that the power need, the most important parameter in the design of the system, could be determined with a minimal error (0.162%) reveals that the thermodynamically analysis could be used in the design of a vacuum precooling system.