Asee peer logo

A Laboratory Exercise To Demonstrate How To Experimentally Determine The Operating Point For A Fan

Download Paper |


2007 Annual Conference & Exposition


Honolulu, Hawaii

Publication Date

June 24, 2007

Start Date

June 24, 2007

End Date

June 27, 2007



Conference Session

Mechanical Engineering Technology Curriculum

Tagged Division

Engineering Technology

Page Count


Page Numbers

12.55.1 - 12.55.9



Permanent URL

Download Count


Request a correction

Paper Authors


Robert Edwards Pennsylvania State University-Erie

visit author page

Robert Edwards is currently a Lecturer in Engineering at The Pennsylvania State University at Erie where he teaches Statics, Dynamics, and Fluid and Thermal Science courses. He earned a BS degree in Mechanical Engineering from Rochester Institute of Technology and an MS degree in Mechanical Engineering from Gannon University.

visit author page

Download Paper |

NOTE: The first page of text has been automatically extracted and included below in lieu of an abstract

A Laboratory Exercise to Demonstrate How to Experimentally Determine the Operating Point for a Fan

Robert Edwards Penn State Erie, The Behrend College


Students often have a difficult time understanding how to determine the operating point for a fan when it is placed into a system. They first have to gain some understanding of fan curves and system flow impedance curves. Then they must superimpose the curves to determine the actual operating point. This can be explained within the context of a lecture, but students seem to gain a better understanding of the concept by actually finding the operating point of a fan in a laboratory setting. This paper describes one such exercise than can be used for this purpose.

In order to run this exercise the students must first learn to generate fan curves and system impedance curves. These preliminary exercises are briefly discussed in this paper. Once they have acquired those skills they proceed to test a real system to determine the fan operating point. An ordinary power supply from a personal computer is used for the demonstration because most of the students are very familiar with the device. The students are required to plot a system flow impedance curve for the enclosure and a fan curve for the fan. They plot both curves and predict what the actual operating point for the fan is when installed in the power supply. Finally, they physically install the fan and measure the actual operating point to see how close they have predicted the actual value.

For exercises like this to be instructive, the students must have a real chance to be successful. The results of this exercise depend heavily on how carefully the students take their measurements for the fan curve and the flow impedance curve, but when reasonable care is taken they can predict the actual operating point within 5% or less. Values within 1% are not uncommon. This gives the students an outstanding chance of a successful outcome.

This paper discusses the equipment used, the preliminary work to learn to produce the necessary curves, the final exercise, and a set of typical results.


The amount of air delivered by a centrifugal fan to an application is not a fixed rate. It varies depending on the amount of resistance to flow that is inherent in the application. This resistance varies with the amount of flow going through the device. A fan needs to be selected which matches the characteristics of both the fan and the device to assure that the required amount of flow will exist within the system.

Edwards, R. (2007, June), A Laboratory Exercise To Demonstrate How To Experimentally Determine The Operating Point For A Fan Paper presented at 2007 Annual Conference & Exposition, Honolulu, Hawaii. 10.18260/1-2--1575

ASEE holds the copyright on this document. It may be read by the public free of charge. Authors may archive their work on personal websites or in institutional repositories with the following citation: © 2007 American Society for Engineering Education. Other scholars may excerpt or quote from these materials with the same citation. When excerpting or quoting from Conference Proceedings, authors should, in addition to noting the ASEE copyright, list all the original authors and their institutions and name the host city of the conference. - Last updated April 1, 2015