There are many kinds of fans available today, with centrifugal and axial fans being the two major types on the market. If you are looking to purchase a fan, it’s important to understand the differences between these two types, in order to select the best fan to handle your needs.
This article will therefore take a deeper look at the differences between centrifugal and axial fans, as well as examining the pros and cons of using each type.
Table of Contents
What are centrifugal fans?
What are axial fans?
Differences between centrifugal fans and axial fans
Conclusion
What are centrifugal fans?
Centrifugal fans are fans that use the principle of centrifugal force to generate airflow.
They consist of an impeller (a rotating disc with blades) that spins inside a housing, which causes air to be drawn in through the center of the impeller and then pushed out radially, creating a flow of air.
Centrifugal fans are commonly used in HVAC, industrial process equipment, and ventilation systems. They are also known as radial fans.
Pros:
- High flow rate makes them suitable for large ventilation systems and industrial processes.
- Adjustable air volume.
- Versatile, making them suitable for both indoor and outdoor use.
- Durable and therefore able to withstand harsh environments.
Cons:
- They are more expensive than other types of fans.
- Limited airflow control making them unsuitable for some applications.
- Require more space making them less suitable for tight spaces.
What are axial fans?
Axial fans are types of fans that use the principle of an axial flow to generate airflow.
They consist of a shaft with a series of blades that rotate around it, called a propeller. The blades are usually parallel to the shaft; they pull or push air in the same direction as the shaft.
The air flows parallel to the axis of the shaft, hence the name “axial” fans. They are often used in HVAC systems, industrial processes, and ventilation systems where a high air volume is needed.
They are also used in electronic cooling and cooling towers. Due to the design of the blades, the airflow rate is relatively constant and independent of the pressure.
Pros
- High volume of airflow, making them capable of moving large volumes of air.
- Low-pressure drops can move air efficiently through a duct system or confined spaces.
- Low noise level making them suitable for use in quiet environments.
- Axial fans are generally less expensive than other types of fans.
Cons
- Not suitable for high-pressure systems.
- High power consumption can lead to increased energy costs.
- The design of axial fans can be complex, making them more difficult to install and maintain.
- Axial fans require a duct system, which adds to the cost and complexity of the installation.
Differences between centrifugal fans and axial fans
Airflow direction
Centrifugal fans generate airflow by drawing air in through the center of the impeller and then pushing it out radially. Conversely, axial fans generate airflow by pulling or pushing air parallel to the axis of the shaft.
Impeller type
Centrifugal fans have an impeller with angled blades to generate centrifugal force. Axial fans have an impeller with blades that are parallel to the shaft.
Centrifugal impellers are better suited for applications where the air needs to be moved in a circular motion and at a 90-degree angle to the inlet. Axial impellers are better suited for applications where the air needs to be moved in a straight line and parallel to the inlet.
Airflow rate
The airflow rate of centrifugal fans depends on the pressure, which increases as the pressure increases. The airflow rate of axial fans is relatively constant and independent of the pressure.
Centrifugal fans are better at quickly moving larger amounts of air, while axial fans are better at moving a larger amount of air over a longer period.
For an axial fan with a speed of 5400 min-1, the airflow rate is 86 in m³/h. For centrifugal fans, the airflow rate is 90 m³/h for a fan with the same speed of 5400 min-1.
Efficiency
Centrifugal fans are more efficient at generating high airflow rates in high-pressure systems. The efficiency of the fan increases as the pressure increases.
Axial fans are more efficient at generating a constant airflow rate in low-pressure systems. The efficiency of the fan is relatively constant and independent of the pressure.
Noise level
Centrifugal fans are designed to operate at low noise levels. They have a more complex design that helps to reduce the noise generated by the fan.
Axial fans are noisier than centrifugal fans, as the air flows through the fan in a straight line and parallel to the shaft’s axis, generating more noise.
The noise level is typically expressed in decibels (dB) units and can vary widely depending on the fan’s size, design, and operating conditions. Most of the centrifugal fans have a noise level of 92 dB. For Axial fans, the noise level is high, reaching levels of 210 Db.
Applicable scenarios
Centrifugal fans have blades that rotate around a central axis, creating pressure that radiates air from the center. They are best suited for applications where a large volume of air needs to be moved over a relatively short distance, such as for ventilation or air conditioning systems.
Axial fans have blades arranged in a parallel plane to the airflow direction. They are best suited for applications where a large volume of air needs to be moved over a long distance, such as in wind tunnels or air handling units.
Conclusion
The above guide expands on what buyers need to know in order to make an informed decision when choosing between centrifugal and axial fans, especially with regard to the propeller type, airflow, airflow direction, and efficiency. It also narrows the decision down to key factors such as your fan needs, budget, and the size of the space that the fan will operate in. To learn more, and to browse listings of quality centrifugal and axial fans, visit Alibaba.com.
