The effects of solar energy and Phase Change Material (PCM) on the energy saving of a desiccant air conditioner have been numerically investigated. Three configurations of desiccant air conditioner (Type A, Type B, and Type C) are investigated at the same ambient conditions to get beater configurations for the energy-saving potential. The difference between the three configurations represents the source of thermal energy used for heating the regeneration air used for reactivation the desiccant material, For Type A the electrical air heater represents the thermal energy source for heating the regeneration air. For Type B the solar energy and electric air heater represent a source of thermal energy for heating the regeneration air. For Type C the solar energy, PCM, and electric air heater represent a source of thermal energy for heating the regeneration air. The numerical results of these simulations are validated by published experimental data, which resulted great agreement between numerical results and experimental data. Also, the economic analysis has been studied to get the beater configurations. The results show that, the average percentage savings in the electrical energy which consumed about 20.85% for Type B and 75.82% for Type C as compared to the Type A. (C) 2018 Elsevier Ltd. All rights reserved.