In winter, the heated dorms have a very poor air quality. This paper intends to establish a fresh air micro-circulation in the dorm through experiments. Three different outlet configurations are designed and made. By studying the distribution of CO2 concentration, air speed and temperature, the best outlet configuration and the best installing place are determined. In a room with a temperature of 24°C, CO2 concentration of 2000ppm, the fresh air device can lower the CO2 concentration in the immediate surroundings of the student down to 680ppm, while maintain a temperature of 21°C and an air speed under 0.18m/s.