Domed roof and evaporative cooling channel as feasible passive cooling techniques have been investigated independently in numerous studies. In the present study, a novel system involving the two techniques simultaneously for meeting comfort conditions was proposed. To this end, 3D CFD simulations of airflow inside and around a 64-m² test building with four domes were carried out. Subsequently, the thermal performance of the system was modeled with a computer code. Effects of both geometric and environmental parameters on the system performance were assessed. The obtained results indicated that the dome's diameter and the dimensions of the cooling channel affect the performance of the system significantly. Also, the proposed system in the present study could supply the required amount of air change per hour (ACH) when the wind velocity is between 0.8 to 3.2 m/s. Furthermore, considering ATCS (adaptive thermal comfort standard), the system provided thermal comfort under a maximum cooling demand of about 112 W/m². Finally, the energy metric and environmental analyses were carried out to compare conventional cooling equipment with the introduced system and four different hybrid systems of domed/vaulted roofs proposed in the literature in terms of the energy consumption and the emission production.