In this study, energy and exergy analysis of a two bed adsorption cooling system have been performed. Silica gel-water has been chosen as the adsorbent-refrigerant pair. Analysis is performed for evaluating the effect of operating conditions on the optimal timing and then on the maximum value of the SCP, COP, effectiveness and the minimum value of internal irreversibility and external irreversibility. A lumped parameter mathematical model and a global optimization method called the particle swarm optimization have been used to reach this purpose. In this model, internal and external irreversibility have been calculated with the new method without calculating irreversibility of the cycle internal component. Energy analysis showed that maximum of SCP increases with the increase of the mass flow rate and heat source temperature. Furthermore, an increase in the heat source temperature causes an increase in the COP, but an increase of the mass flow rate causes a decrease in the COP. Exergy analysis reviled that depending on the mass flow rate and heat source temperature, 65-90% of input exergy was expended by internal irreversibility, 1–20% were expended by external irreversibility and 8-14% is transferred to the cold reservoir in evaporator. It is concluded at the low-temperature heat source if the mass flow rate is chosen less than 0.6 kg/effectiveness at heat source temperature 75 is more than 65 and vice versa.