Types of Fans

Fans commonly used in daily life can be categorized by their power source into two types: AC fans, which operate on alternating current, and DC fans, which run on direct current. They can also be classified by their shape and airflow mechanism into axial fans, blowers, and centrifugal fans.

SANYO DENKI offers a wide range of fan models, each designed for different applications. Let’s take a closer look at the differences among them.

Fan Types: Differences by Power Source

First, there is the difference in the power source that drives the fans. There are two types: AC fans, which use power from a wall outlet, and DC fans, which run on direct current. AC fans operate at a fixed rotational speed determined by the power supply’s frequency, whereas DC fans can vary their speed using a motor and control circuit.
Today, DC fans are widely used due to their ease of control and wide variety of available models. There are also ACDC fans, which convert AC power into DC and operate like DC fans, even when connected to a standard AC outlet.

Fan Types: Differences by Shape

The most commonly used type is the axial fan.
It has blades mounted at the center of a frame and draws air in from the front and expels it to the rear. This is the type of fan most people picture when they hear the word "fan." Axial fans are widely used because they offer high airflow and tend to operate with low noise.
There are several variations of axial fans to suit different needs. Counter rotating fans, which are made out of two axial fans arranged front to back, with the blades rotating in opposite directions to improve airflow linearity and generate high static pressure; endurance fans, which can be used in harsh environments or at extremely high or low temperatures; and reversible flow fans, which can blow air in both directions by reversing the rotation direction of the blades.

Unlike axial fans, blowers and centrifugal fans redirect airflow by 90 degrees—from inlet to outlet—rather than pushing air straight backward.
These fans are especially useful in devices where space constraints prevent air from being discharged directly behind the unit. Blowers are ideal for spot cooling and for equipment with densely packed components because they can generate high static pressure. Centrifugal fans are also useful for extracting air from tightly enclosed equipment. The features of each fan type will be explained in more detail later.

* Fans are labeled with symbols indicating airflow direction and blade rotation.
Be sure to check these symbols before installation and review the specifications to ensure compatibility with your equipment.
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Supervised by: SANYO DENKI CO., LTD. Cooling System Design Department

Update date: 2022-03-18 00:00 /release date: 2018-01-16 00:00