The main objective of this article aims to enhance a single stage absorption refrigeration machine, using the ammoniawater pair as working fluid, and this from the improvement of its exergetic performances by means of a vapor rectification system. The rectifier makes it possible to emit a vapor enriched in pure fluid (ammonia) with a high flow rate; this one is thus transformed into condensate after condensation; as it also allows evacuating a liquid (water) in the form of reflux. Moreover, in order to show the role of the rectifier and to highlight its impact on the operation of the proposed installation, the methodology adopted in this work aims to develop a thermodynamic model of numerical simulation using the FORTRAN language according to two approaches. An energetic analysis approach which aims to assess, in a first time, the performance of the studied refrigeration installation. However, the exergetic approach tries to calculate the exergy efficiency, and thus to evaluate the losses of exergies of the refrigeration installation in a second time. Therefore, the obtained results showed a clear improvement in the exergetic efficiency, accompanied against by an optimization of the losses of exergies which are due to the irreversibility of the studied thermodynamic system. The novelty brought by the present study encourages the engineers and manufacturers to realize the future absorption refrigeration machines integrating rectifier systems.