This paper presents a study of the mass transfer characteristics of a spray column being used as a dehumidification device for air. The experiment was conducted using high humidity air and polyethylene glycol (PEG) as a desiccant solution over a range of process conditions including various liquid flow rates, gas flow rates, water concentrations of PEG, temperatures of PEG, and nozzle diameters. The performance of the spray column was evaluated in terms of volumetric mass transfer coefficients. The results were well expressed by the correlation using dimensionless groups including the physical properties of the liquid and nozzle diameter.