Turbine ventilator is an equipment that uses natural wind force to bring out the rotation of the turbine and creates a negative pressure at the down-stream end of the pipeline to exhaust airflow. The form and designing concept are quite simple, yet it is ideal in practicality. Turbine ventilators are widely installed in Taiwan to enhance building ventilation (especially with spaces like bathrooms and kitchens where negative pressure is highly demanded) and the ventilation of factories. Theoretically, the proper combination of turbine ventilator and natural ventilation will help tremendously the indoor air quality while it will also decrease the reliance on air-conditioning and thus reduce the energy consummation. It is indeed a field of environmental design engineering that demands profound research.To acquire the common operation mode of the application of ventilators in Taiwan and the ventilation they induce, we use low-speed tunnel experiment to conduct a variety of tests on different styles of ventilators. And the results show that it is indeed helpful to increase ventilation with the installation of ventilators. The bigger the ventilator is with inner vanes, the better ventilation is guaranteed. However, the size (0.5 m/0.36 m) of the turbine ventilators and the availability of inner vanes do not mark significant differences in the ventilation rate induced. (C) 2003 Elsevier Science B.V. All rights reserved.