Desiccant systems have been proposed as energy saving alternatives to vapor compression air conditioning for handling the latent load. Desiccants are classified as either liquid or solid. The main components for a liquid desiccant system are the dehumidification and regeneration towers. This paper presents the results from a study of the performance of a packed tower absorber for lithium chloride desiccant dehumidification system. A finite difference model was developed to determine the packing height of the dehumidification towers. The finite difference model was written in MATLAB language which is a suitable model to measure the optimum height of a tower. The paper also examines the effects of different design parameters on the height of a packed tower using a mathematical model. The effects of air and liquid flow rates, air humidity, desiccant temperature and concentration were reported on the packing height and humidity effectiveness of the column. In conclusion the results of the present study are compared with previous experimental studies.