SYNOPSIS In the present communication, the authors have studied the performance of a rotary bed solid desiccant adiabatic dehumidifier. A Bry-Air dehumidifier has been installed in Delhi at the Solar Refrigeration Laboratory of the Centre of Energy Studies and performance testing has been carried out. On the basis of conservation equations for mass/material and energy balances, theoretical performance results were obtained from a modified computer model [1]. These have been compared with the experimental test results for the dehumidifier for a practical range of operating conditions. It was found that there is a qualitative agreement between the test results and the theoretical predictions.