Shenzhen, Guangdong, China – October 22, 2026

I. What is a common Axial Fan series connection?

By “common series connection”, we mean installing two identical or nearly identical axial fans in the same air duct.

The direction of air flow is as follows:

Air → 【Fan A】 → 【Fan B】 → Outflow

Many people believe:

• The first fan pushes the air;
• The second one continues to push the air;
• Therefore, the static pressure naturally doubles.

In fact, this is only an ideal situation.

Air is not a straight line; rather, it is a fluid with complex characteristics such as rotation, turbulence, and vortices.

What truly affects the performance of a fan is not just the air volume, but rather the flow field state of the air after it leaves the impeller.

II. Why do ordinary axial fans generate vortices?

When an axial fan is operating, the impeller rotates at high speed.

After passing through the blades, the air does not flow purely axially. Instead, it forms a rotating airflow at a certain angle (Swirl Flow).

It can be simply understood as:

Normal expectation:

↓↓↓↓↓↓↓

In fact:

↺↺↺↺↺↺

↓↓↓↓↓↓

That is to say:

The air flows forward.

It is still rotating on one side.

The greater the rotational speed is,

The air is more likely to form:

• Air flow swirl (Swirl)
• Turbulence
• Energy loss

All of these will reduce the effective airflow that can actually reach the radiator.

III. Why is the effect limited when two ordinary fans are connected in series?

Now let’s look at the second fan.

Many people believe that:

The second fan can continue to accelerate the air.

In fact, it is not like that.

If two fans rotate in the same direction, for example:

The first one:

↺

Second machine:

Then the second fan encountered the following situation:

Air already with rotational angular velocity.

So the second impeller continued to intensify this rotation.

The result is:

The first one:

↺

Second machine:

↺↺↺

The air is spinning more and more.

The air is moving in circles more and more, rather than becoming straighter.

Ultimately leading to:

• The eddy current increases
• The energy loss increases
• The wind pressure increase is limited
• The noise increases
• The efficiency decreases

Therefore, two ordinary axial fans connected in series cannot be equivalent to a high static pressure fan.

IV. What is a dual-reverse fan?

A dual-reverse fan is also composed of two sets of impellers.

But the biggest difference lies in:

The rotation directions of the two sets of impellers are completely opposite.

For example:

Front impeller:

Counter-clockwise

↺

Rear impeller:

Clockwise

↻

The structure is as follows:

Air →

Front impeller

↺

Rear impeller

↓↓↓↓↓↓↓↓

Air flows out in a straight line.

This is the core design concept of the dual-reverse fan.

V. Why is reverse rotation more efficient?

The answer lies in:

Eliminate the vortex.

After the front impeller has been in operation,

The air has a rotational speed.

If the rear impeller rotates in the opposite direction,

It will not continue to increase its rotation.

Instead, it will:

Cancel rotation.

The state of air flow will change.

Simple Series Connection:

↺↺↺↺

It’s getting more and more chaotic.

Double reversals:

↺

↻

↓↓↓↓

Restore the straight flow.

The air becomes more concentrated.

More stable.

Closer to the axial direction.

The rotational kinetic energy in the air.

Reconverted to:

Axial flow velocity.

So:

• The effective air volume has increased.
• The static pressure has significantly increased.

VI. Why are dual-reverse fans particularly suitable for high-density equipment?

In recent years, various electronic devices have been developing in two directions:

First, miniaturization.

The devices are getting thinner and thinner.

For example:

• 1U server
• Edge computing device
• Industrial control computer Network switch

Second, high power.

The power consumption of GPUs continues to increase.

The temperature of the AI server is increasing rapidly.

The integration degree of communication equipment is getting higher and higher.

This means:

• There is less and less space available for installing fans.
• And the amount of heat that needs to be removed is increasing.

The traditional method of increasing the size of the fan has become inadequate to meet the demands.

Therefore, the dual-reverse fan with high static pressure and small size has become one of the solutions.

Through redesign:

• The front and rear impellers Motor
• Blade frame
• Drive circuit

The dual-reverse fan can achieve higher air pressure and higher heat dissipation efficiency within a limited space, and is highly suitable for high-density installations.

VII. In which industries are dual reversing fans mainly applied?

Due to their features of high static pressure, high air volume and high efficiency, dual reversing fans have been widely used in scenarios with high resistance for heat dissipation, including:

• AI servers and GPU servers
• 1U/2U high-density servers
• Telecommunication equipment Network switch
• Data Center
• Industrial computer
• Edge computing device
• Energy storage PCS and inverter
• Industrial control equipment Medical equipment

For these devices, the available cooling space is limited and the air ducts are complex. Ordinary axial fans alone often fail to meet the cooling requirements. However, dual reversing fans can provide higher static pressure and more stable airflow within the limited installation space.

About Us

Shenzhen Fuqingda Electronic Technology Co., Ltd. was established in 2006 in Shenzhen, China. It is an enterprise that integrates product design, research and development, production, and sales.

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