In this work, the governing equations of coupled heat and mass transfer are developed based on the conservation of energy and moisture in air and desiccant layer of a rotary desiccant wheel in order to consider both the solid-side resistance (SSR) and gas-side resistance (GSR). The simulations are done for composite desiccant and conventional silica gel. The properties of air and desiccant are taken as function of temperature in the adsorption and regeneration sections. The governing partial differential equations are discretized using the finite-volume method with fully implicit scheme and the resulting system of algebraic equations is solved using the Gauss–Seidel method. The model is validated for the moisture removal capacity and relative moisture removal efficiency by comparing the present results with the literature data. The parametric simulations are performed by varying one parameter at a time with the angle of regeneration section kept in a range from 60 deg to 300 deg. The selection of regeneration section angle and temperature of regeneration air is discussed for operating the rotary desiccant wheel at its optimum performance for the range of operating conditions.