As a comprehensive system of natural ventilation and smoke control for atrium buiIding, an atrium building with a solar chimney is proposed. In this building, natural ventilation is acauired with stack effect prompted by solar energy collection at the chimney. In case of a fire, the escape route is secured from smoke by keeping the neutral pressune plane in the chimney and the pressure of atrium lower than outside. The purpose of this paper is to establish the easy prediction of natural ventilation rate of this atrium solar chimney with zone modeling and grapes the characteristic and performance of the natural ventilation system through the modeling. To obtain ventilation rate, area rate of outlet/inlet 2 and higher chimney are advantageous. The necessary condition of the smoke control in the prototype building is to set the area rate of outlet/inlet greater than 2 and the height of the chimney greater than 20% height of the whole building. The condition satisfying the smoke control is automatically advantageous to natural ventilation and the requirements for natural ventilation and smoke control is compatible.
