123ArticleOnline Logo
Welcome to 123ArticleOnline.com!

ALL >> General >> View Article

Fan Performance Curves

By Author: Oleg Tchetchel
Total Articles: 27

Fan curves are based on laboratory test data and are sometimes referred to as "test curves". A typical test curve will often define the performance parameters for a specific design and size of fan, operating at a given speed, moving a gas of a given density. Inspection of this graph will show that it is actually composed of four separate curves:

• Static Pressure vs. Volume Curve: This plot is the one often referred to as the "fan curve" or "characteristic curve" because it defines all the possible pressure-volume combinations the fan is capable of producing given stated conditions (i.e. rpm and gas density). Note that this curve has two regions - one marked by dashed lines and the other by a solid line. Fans must be selected so that the design point is located on a solid portion of the curve, preferably in an area of high operating efficiency. Operation on the dashed portion of the curve should be avoided as it is a zone of potentially unstable performance. For this reason it is wise to allow some reserve between the peak static pressure and the design pressure to compensate for a higher resistance to flow than anticipated by the design calculation.

• Static Efficiency vs. Volume Curve: In most instances it is desirable to have a fan perform as close to its peak efficiency as possible. The static efficiency vs. volume curve illustrates the efficiency of fan performance at a glance.

• Power vs. Volume Curve: This plot illustrates the power draw of the fan for any point on the characteristic curve.

• System Curve: The system curve defines the volume flow rate versus pressure characteristics of the system in which a fan will be installed.

The fan curve is a graphic presentation of fan performance. It is one of the most useful tools available during the fan selection process. While multi-rating tables are convenient, performance curves offer additional information such as - how much reserve pressure head exists between the design pressure and the peak static pressure, the maximum power the fan might draw, and the efficiency of operation.

For most applications, the volume flow rate to pressure relationship is governed by the following equation, often called the "duct law":

Once the system designer has determined the system pressure loss (P) for one flow rate (CFM), it is very easy to calculate the corresponding pressure loss for any other flow rate using this "law". The system curve is not included on the performance curve when it is issued from the fan manufacturer and its determination is left to the system designer.

At this juncture it is prudent to reiterate that a fan running at a particular speed can have an infinite number of operating points all along its characteristic curve. The fan will interact with the system to produce an operating point at the intersection of the system curve and the fan curve. Note that it is the system in which the fan is installed that will determine the operating point on the fan curve. Thus it is vitally important that the system designer accurately determine the system losses in order to ensure that the actual air flow rate is as close as possible to the design air flow rate.

For additional information please refer to http://industrialpressureblower.com/fan.html

Oleg Tchetchel
Canadian air systems designer
blower@industrialpressureblower.com
Industrial Pressure Blower Co.
http://www.industrialpressureblower.com/fan.html
http://industrialpressureblower.com/inquiry.html

Total Views: 53Word Count: 549See All articles From Author

General Articles

1. Get Environment-friendly With Toronto Electronics And Battery Recycling Procedure
Author: johna smith

2. Find Chapati Making Device Price Quickly On On The Internet
Author: danielcaron86

3. How Hibernate Framework Works In Java
Author: infocampus

4. All You Need To Know About Alibaba Clone Script.
Author: akshay

5. Why Water Quality Is Very Important For Water-jet Cutting?
Author: Colin Sponias

6. Architectural Visualisation And Rendering
Author: Blitz 3D Design

7. Los Angeles Photo Booth For All Sorts Of Occasions
Author: lafotoevents

8. Error Code 0xc190020e-windows 10 Update Issue
Author: Martin

9. How To Make The Most Of Booking A Dfw Airport Car Service For Your Business Trip?
Author: Skyler Town Car Service

10. 3 Sure Shot Ways To Increase Mobile Ad Revenues.
Author: Sameez

11. Buy Tirunelveli Halwa Online
Author: manju

12. Les Anges Plus De Vêtements De Bébé Sont Aussi Le Mercredi Sherobe
Author: sherobe

13. Steel Piles: H-piles, Piling Pipes
Author: threeway steel

14. Aadhar Address Change And Update Status
Author: Pranalisharma

15. Boost Your Drupal Development With Docker
Author: valuebound

Login To Account
Login Email:
Password:
Forgot Password?
New User?
Sign Up Newsletter
Email Address: