1. One of the following types of fans: vaneaxial, tubeaxial, or propeller. Such fans impart energy to the air by giving it a twisting motion. They are specified by blade shape, ratio of hub-to-tip diameter, pitch of the blades, and number of blades. Guide vanes may be added to straighten the flow and increase the efficiency.
2.See centrifugal fan.
McGraw-Hill Dictionary of Architecture and Construction. Copyright © 2003 by McGraw-Hill Companies, Inc.