“Cooling fans” are surely familiar to everyone—whether it’s inside computers, water dispensers, refrigerators, air conditioners, air purifiers, cars, or countless other devices, you’ll find them everywhere. However, the term “cooling fan” is merely a generic umbrella term for all types of fans. So how much do you really know about the specific classifications of cooling fans? At the most basic level, cooling fans can be categorized according to their power supply: those powered by DC are called DC cooling fans, while those powered by AC are called AC cooling fans. These are the fundamentals, and I’m sure most of you already know about them. Today, though, I’d like to focus on another classification—namely, the different directions of airflow they employ. Broadly speaking, there are four main categories:

Cooling fans are widely used in industrial production, primarily for cooling, temperature reduction, and dust removal in large-scale production equipment. Given that typical industrial environments are often quite complex, to extend the service life of cooling fans, it’s essential to perform certain treatments—such as the most common one: corrosion prevention. For instance, what causes cooling fans to leak or splash oil? Today, we’ll show you how to prevent corrosion in cooling fans.

According to the direction of airflow entering and exiting the cooling fan, they can be classified into the following types: axial-flow fans, centrifugal fans, mixed-flow fans, cross-flow fans, and blowers. Additionally, based on their power supply type, cooling fans can be further divided into DC cooling fans and AC cooling fans.

As the name suggests, a micro cooling fan is a small, miniature cooling fan designed for use in spaces with limited room. With advancements in technology, we increasingly demand devices that are not only more convenient but also more compact. As a result, the applications of micro cooling fans are becoming ever more widespread. Today, let’s explore the noise factors associated with micro cooling fans. As we all know, micro cooling fans tend to generate less noise compared to their larger counterparts. But what other factors influence noise levels?

1. What are the main factors contributing to noise generation? The noise generated by miniature fans is related to friction and airflow. The higher the rotational speed and the greater the air volume, the louder the noise will be. In addition, the vibration inherent in the miniature fan itself is also a factor that cannot be ignored. Of course, high-quality miniature fans have very little inherent vibration; however, the first two factors—friction and airflow—are difficult to overcome.

As is well known, many industries currently rely on cooling fans—ranging from small electronic devices to large refrigerator cabinets. Cooling fans help keep product temperatures within a manageable range, thereby extending the service life of these products. The cooling fan market is large in scale, and competition among cooling fan manufacturers is intense. Moreover, different manufacturers offer cooling fan models with varying features and functionalities.

A DC (direct current) fan receives direct current as its input. Common DC voltage levels include: 3V, 12V, 24V, 32V, 48V, 5V, 60V, 25.5V, 42V, 18V, and 15V. The operating principle is based on Ampère’s right-hand rule: when a current flows through a conductor, a magnetic field is generated around it. If this conductor is placed within a stationary magnet, an attractive or repulsive force will be exerted, causing the object to move. Inside the blades of a DC fan, rubber magnets that have already been magnetized are attached. These magnets are arranged around silicon steel laminations. At the center axis, two sets of coils are wound, and a Hall-effect sensor is used as a synchronous detection device to control a circuit. This circuit causes the two sets of coils wound around the axis to alternate in operation. As the silicon steel laminations generate alternating magnetic poles, these poles interact with the rubber magnets, producing either attraction or repulsion. When the resulting magnetic force exceeds the fan’s static friction, the blades begin to rotate naturally. Thanks to the synchronous signals provided by the Hall-effect sensor, the blades continue to rotate smoothly. As for the direction of rotation, it can be determined using Fleming’s right-hand rule.

During operation, cooling fans will inevitably produce some noise. However, the noise levels vary from fan to fan—some are louder, others quieter. So how exactly is this noise generated, and what can be done about it? 1. Noise is also generated when vortices form behind the blades. As the fan rotates, vortices develop on the back side of its rotating blades. These vortices not only reduce the fan’s efficiency but also create noise. As the fan rotates, vortices develop on the back side of its rotating blades. These vortices not only reduce the fan’s efficiency but also create noise. To minimize this phenomenon, the blade installation angle must not be too large, and the blade curvature should be smooth without any sudden, drastic changes. To minimize this phenomenon, the blade installation angle must not be too large, and the blade curvature should be smooth without any sudden, drastic changes.