Axial Flow Fans date back to the horizontally configured windmills of Europe in the Middle Ages. The first electrically powered fans, introduced in the 1880s, were axial fans. Axial fans are named for the direction of the airflow they create. Blades rotating around an axis draw air in parallel to that axis and force air out in the same direction. Axial fans create airflow with a high flow rate, meaning they create a large volume of airflow. However, the airflows they create are of low pressure. They require a low power input for operation. http://www.dhlcentrifugalfan.com/axial-flow-fan/