The primary aim of this study is to simulate numerically the heat and mass transfer characteristics in the annular adsorber that is the most important component of the solar cooling machine, and to evaluate the solar and thermal coefficients of performance as an optimisation criterion of the system, for different adsorbent/adsorbate pairs. The porous medium constituted of the adsorbent/adsorbate is contained in the annular space and it is heated by solar energy. A general model equation is used for modeling the transient heat and mass transfer. The adsorption phenomenon is described by using different models of solid-adsorbate equilibrium. Effects of the key parameters on the adsorbed quantity, the generating temperature, the performance coefficients and thus on the system performances are investigated.