Date of this Version



© 1995. The Board of Regents of the University of Nebraska on behalf of the University of Nebraska–Lincoln Extension. All rights reserved.


This publication describes how to use fan performance and system resistance data to achieve the desired effect and efficiency of a ventilation system.

Many people perceive ventilation simply as a fan. However, effective ventilation of a livestock building or the aeration of stored grain requires a complete ventilation system.

A simple ventilation system may consist of fans to move the air, inlets or outlets for air distribution, and manual controls. More complex systems may include ducts, perforated floors, automatic controls, and other components. Regardless, all components must be carefully designed, selected, installed, managed, and maintained to achieve satisfactory results.

A fan is a mechanical device that uses energy inputs to move air, and can be thought of as the "heart" of a mechanical ventilation system. A basic understanding of fan performance is important when selecting and managing a mechanical ventilation system, regardless of the application.