What is a Centrifugal Fan & How Does it Work?

Fan Parts - Inlet Box Damper Silencer WeatherhoodCentrifugal fans (centrifugal blowers) are a common type of fan used in consumer and industrial products to move air or other gases. A centrifugal fan consists of three main components: a motor, a fan blade, and an enclosure.

All of these components can be designed to accommodate an application. Some common design criteria are the size of the motor, the shape of the fan blade, the direction of rotation, and the materials of construction.

How a Centrifugal Fan Works

The rotating fan blade creates a low-pressure area at the center of the blade and a high-pressure area at the edges of the blade along with adding kinetic energy to the air. The low pressure area at the center of the fan creates a vacuum that draws air into the fan. The air flows from the center of the fan to the outside edges of the fan and then, ultimately, out of the enclosure around the impeller in the desired direction. The flow path makes a 90 degree turn in most cases which is accounted for in the design of the overall system.

Backward Inclined Fan with accessories.

Centrifugal fans come in a variety of designs which are determined by the type of fan blade used, the design of the enclosure (housing), and the materials of construction.

Common categories for impellers include forward or backward curved impellers, backward inclined impellers, and flat paddle wheel style impellers, all of which have their own unique performance characteristics. AirPro offers a comprehensive selection of centrifugal fan designs including:

For a comprehensive description of AirPro’s industrial centrifugal fans, visit our product page.

Applications, Safety & Maintenance

Industrial centrifugal fans and blowers are manufactured to accommodate a variety of applications including but not limited to chemical processing, cooling systems, corrosive gas handling and fume control. Centrifugal fan applications such as dust collection, air pollution control, or general ventilation often involve a pressure drop that has to be overcome.

Industrial applications often have special requirements and are frequently custom built with safety and reliability being key areas of importance. All AirPro industrial centrifugal fans are inspected, tested and engineered to meet the highest levels of quality and safety including AWS standard certification and QC documentation included in every shipment.

Proper maintenance is critical to the successful operation and long fan life. Centrifugal fans should be equipped with features that make routine maintenance easy. To accommodate gases or materials in the airstream and to increase the life of the blowers, special finishes are added for protection including industrial enamel, specialty paints, powder coating, and custom linings.

4 Common Centrifugal Fan Applications:

Dust CollectionCentrifugal fans are well suited for dust collection applications because they can overcome pressure drops across the filter and provide the constant drawing power required to maintain clean, breathable air.

DryersCentrifugal fans are indispensable in agricultural rotary or spray dryers in which air must be circulated to control temperature and moisture. AirPro manufactures high-efficiency, high-temp industrial fans and blowers to accommodate drying grains, chemicals, powders and other products.

Material Handling – AirPro fan blowers can handle virtually anything from light materials like wood chips, sawdust, and pet food to heavy materials including light metal scraps, carbon steel, and other heavy-duty alloys.

Process Heating – Both pre-engineered and custom designs can fit the requirements of forced and induced draft air for process heating in ovens, furnaces, boilers, burners, and heaters.

To view a full list of centrifugal fan applications, click here.

Customizing a Fan

Many industrial fans are built to suit a specific set of design criteria. We recommend working with an AirPro fan selection expert to design the best fan to meet your criteria. You will be working with industry-leading fan engineers to create customizable solutions to match your project requirements and budgets.

Centrifugal Fans vs. Axial Fans

Industrial Exhauster Fan | Radial Shrouded

Centrifugal Fan Wheel

airpro axial fan blade

Axial Fan Blade

Both centrifugal fans and axial fans are commonly used in industrial environments, but they have very different performance characteristics.

Axial fans are used in applications where a large flow rate is required with minimal drop in pressure. Axial fans pass air straight through the blades instead of creating a 90-degree turn in the direction of flow. If there is not a large pressure drop in the application, the axial fan can be preferable due to form, fit, & function.

In industrial contexts, axial fans are often used in equipment to exchange heat through environmental air such as Air-Cooled Condensers, Cooling Towers and Air Cooled Heat Exchangers. Examples include:

  • Field erected cooling towers often utilized in industrial processes and in power generation facilities.
  • Package cooling towers which are mainly used in HVAC applications.
  • Air-cooled condensers which are a critical component in power plants and typically utilize large diameter fans.
  • Air cooled heat exchangers (ACHE) which are used primarily in process industries (petrochemical, oil refining and gas compression).
  • Forced ventilation systems.

Centrifugal fans are typically placed in areas of little to no natural ventilation and are attached to a duct system, making them ideal for larger spaces.

When deciding which style of fan to use, you may want to consult an expert. AirPro application engineers will be able to examine your performance and installation requirements to assist you in determining which type of fan is most ideal for your specific application.

For more information on centrifugal fans and applications or to find a customizable solution for your specific needs, contact our experts here or call us at 715-365-3267.

What is a centrifugal fan? – What is a centrifugal blower? – Axial Fan Vs Centrifugal Fan