Fan Buyer's Guide

By: Robert Cong
Product Manager & Technical Copy Writer


Fans spin and cool... simple, right? Actually, electronic components are never that simple. When it comes to purchasing the correct fan, you have to look at all the specifications such as size, speed and control in order to make the right choice for your application.

Input: It Won't Work If You Can't Power It
Make sure you know what kind of input will be provided before deciding on anything else. The most common voltage inputs are 5VDC, 12VDC, 24VDC, 48VDC, and 115-220VAC powered. Be sure your system can provide the required amount of current for the fan to operate to expectations.

Size: Bigger Doesn't Always Mean Better
The size of the fan will be determined by how much space you have to work with. The larger the fan does not always translate to higher speeds or better cooling. It simply means that a larger area will receive cooling. Conventional standards list the sizes in millimeters, and the most common are 40x40x10, 80x80x25, and 120x120x25.
Fan
Bearings: The Foundation Of A Fan
The bearing on a fan tells you how the fan is built and also provides you with an idea of how long it may last. Ball bearing fans are the most common as they are simple and effective. They are also more durable at higher temperatures and fairly quiet at high speeds. They have a long lifespan, many lasting over 60,000 hours.

Ball Bearing Diagram
Ball Bearing Diagram

Sleeve bearing fans are also very common. They use lubricated sleeve surfaces which can be self-lubricating and require little maintenance. Although they are generally less expensive, they are also known to be less reliable long-term and do not perform as well as ball bearing fans in higher temperatures.

Sleeve Bearing DiagramSleeve Bearing Diagram

Hypro bearings are used exclusively from Adda Fans. They are recommended for fans with a minimum thickness of 10mm and for applications under 70°C. Hypro bearings are made of copper ferroalloy which have an above average lifespan and are water-resistant and good for low-noise applications. They also use lubricating oil within the system, which reduces friction but may cause additional wear once it dries out.

Hypro Bearing DiagramHypro Bearing Diagram

Vapo bearings are used exclusively from Sunon Fans. They are designed to virtually eliminate any wobbling, so they stay incredibly stable in all applications. They also stay dust-proof leading to much improved life expectancy.

Vapo Bearing DiagramVapo Bearing Diagram

Speed And Airflow: A Major Factor In Staying Cool
The rotational speed of a fan is usually given in revolutions per minute (RPM). Combine the RPM speed with the static pressure of the given environment and you get the airflow of the fan, usually given in cubic feet per minute (CFM). This spec will tell you which fans push around the most air and provide the most cooling.

Connections: An Extra Lead Could Save Energy
Most fans have a simple 2-lead positive/negative connection, but some may include extra leads for various purposes. A third lead can be used in certain fans for locked rotor protection in case something gets caught in the propellers. Some fans also have a temperature sensor so that the fan only turns on once the system reaches a predetermined temperature, saving energy in the process. A tachometer lead may also be available for users that want to know exactly how many RPMs are being provided.

Fan Guards: You'll Want The Extra Protection
For those who want extra protection from debris and the harsh environment, there are fan guards and washable filters. Keep unwanted material from traveling in and out of your fans and prolong its life in the process.

Mesh Fan GuardMesh Fan Guard
Washable Aluminum FilterWashable Aluminum Filter

Conclusion
There are more considerations to take note of such as agency approvals and noise levels, but those are fairly straightforward. If your purposes require certain approvals, please make sure they are marked so.

Click here for explanations on Certifications and Approvals: http://www.ul.com/global/eng/pages/corporate/aboutul/ulmarks/mark/

Jameco offers a large selection of Fans and Accessories

AC Tube Axial Fans
Blowers
DC Brushless Fans
Heat Sinks
Fan Guards and Accessories
Fan Power Cords
Fan Grab Bags

Jameco is a preferred supplier representing the following manufacturers:

Adda Inc
AVC America Inc.
Comair Rotron
Common Wealth
Delta Eelectronics
EBM-Papst
Elina
Evercool Thermal Corp., Ltd
Fulltech Electric Co.
Intel Corporation
Jameco ValuePro
Jamicon Corporation
Japan Servo
Mechatronics Inc
Nidec Corporation
NMB Technologies
Sanyo Denki
Sunon
YS Tech USA

Robert Cong is a Technical Copy Writer & Product Manager for Jameco Electronics. He graduated with a degree in Electrical Engineering from Cal Poly San Luis Obispo in California. His interests include sports, movies, music, and playing with cool, new gadgets.