Recently, sorption technology has taken significant attention as an alternative process to mechanical air conditioning systems for dehumidification of air without lowering the air dry-bulb temperature below its dew point temperature. In this perspective, an aqueous lithium chloride (LiCl) is considered as a more effective desiccant in desiccant sorption systems due to its higher moisture absorption capability. In the present study, an effort is made to develop a simple correlation to predict the vapour pressure of LiCl solution as a function of solution temperature and concentration. Based on the developed correlation, an Othmer chart is constructed for LiCl solution in the concentration range of 20–40% and 15–50 °C temperature range. A trade-off analysis has also been carried out among the performance parameters. It is shown that venture of optimum outcome is observed at solution to air flow rate ratio of 8.5 with a condensation rate, moisture and enthalpy effectiveness of 0.234 g/s, 71.5% and 72.5%, respectively. Subsequently, empirical regression models are developed for predicting the performance parameters, which reveals that the developed models are robust for surrogate modelling in dehumidifier testing paradigms.