Zeolite 13X molecular sieve with high sorption capacity and significant sorption rate has been considered a promising candidate for seasonal heat storage. In this study, a code is developed to simulate the adsorption process between zeolite and water in all ranges of partial pressures, temperatures, and sorbate loadings. The results from the proposed code were compared with experiments and good agreement was observed. After validation, the developed model was used to study the effective parameters involved in the adsorption process of binder-free Zeolite 13X. A parametric study considering various temperatures and water content in the inflow air was conducted and the influence of different factors on the outlet temperature and adsorption enthalpy has been studied. This parametric study gives a good insight into the measures which can be taken for achieving the desired released energy or having the outlet temperature in the preferred range. The simulations have been conducted in a variety of temperature ranges provided during the desorption process, the humidity amount, and the mass flow rate of the incoming air. The relative influence of each parameter in the specified ranges is presented. The results have demonstrated the direct relationship of the partial pressure of water vapor and the desorption temperature with the adsorbed water amount and adsorption enthalpy while changing the mass flow rate mostly influences the discharging time.