This short communication presents the update on the desiccant wheel models, developed earlier by the present authors. It is to be mentioned here that the psycrometric model presented earlier (Int. J. Energy Res., 2003; 27:17) is valid only for the desiccant wheel running with identical volume air-flows in supply and regeneration sides. However, when system runs with volume air flow ratio between supply and regeneration side (α), different from 1 (one), the model need further modifications. In the present work, correction factors were developed and incorporated in order to update the earlier model for predicting correctly the temperature and humidity of processed air at the outlet of desiccant wheel. The modified model were verified against the experimental results corresponding to different values of α, obtained from the industry for three different kinds of desiccant wheels. Copyright © 2004 John Wiley & Sons, Ltd.