An experimental investigation of connected fluidized beds was conducted to study the sorption and desorption characteristics of a new organic sorbent material (HU720PR) for air conditioning systems. Sorption and desorption performance was evaluated for varying initial fluidized bed heights, sorbent powder circulation rates, and air flow velocities. The results indicated significant improvement in sorption/desorption as the air flow velocity increased. It was found that circulation rate has optimal rate on the humidification. An optimal height for the sorbent powder was identified, based on the operating conditions. Non-dimensional correlation equations were developed to describe the water vapor mass transfer processes during sorption/desorption, in terms of relevant non-dimensional parameters. (C) 2013 Elsevier Ltd. All rights reserved.