The subway is a common transportation system accessed by over 8 million people on a daily basis in Metropolitan Seoul area. The subway ventilation system located on a street occupies a large area of walkways which cause inconvenience to the public. In this paper, approaches to reduce the ventilation sitting area on the pathway are examined. 5 different preliminary models of ventilation systems are analyzed to minimize the pathway obstacle area such that the public may have an easy access to pass by on the street. The amount of the air ventilation is predicted using the CFD software to ensure an efficient ventilation. The ventilation performance is verified by theory and numerical analysis. The result shows that one of the proposed model combined with the hybrid ventilation satisfies the regulation requirement of the air quantities. We may conclude that the proposed ventilation design provides a smooth walking environment to the public while the ventilation volume is maintained to the existing ventilation system with no modification of the current ventilation holes and structures.