What is a Centrifugal Fan & How Does it Work?
Centrifugal 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.
Our application engineers design all of these components 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. It also adds 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. Ultimately, it flows out of the enclosure around the impeller in the desired direction. The design of the overall system accounts for the 90-degree turn in the flow path. Below is an example showing a Backward Inclined Fan with accessories.
Centrifugal fans come in a variety of designs. Several components, including the type of fan blade used, the design of the enclosure (housing), and the materials of construction, determine the complete fan design.
Industrial centrifugal fans and blowers accommodate a variety of applications. For example, chemical processing, corrosive gas handling, dust collection, dryers, fume control, process cooling, and process heating. Below are some of the most common, with links to more information and related fan designs.
5 Common Centrifugal Fan Applications:
In industrial operations and facilities, air movement is always part of the process. Air handling fans support your operations and the ambient air in the vicinity. Processes span from industrial system components to makeup air units and removing to refreshing. We design and build centrifugal fans specifically for your industrial clean air handling application. Learn More
Industrial processes use light dust loading and fume extraction fans as part of the overall dust collection system for air quality improvement and safety. They move the air and materials through the system to capture, collect and convey the particles through various parts of the system. These can include hoods, air filtration, a collector such as a baghouse, traps, and of course ductwork. Learn More
Centrifugal force material handling fans can process particles such as sand, plastic pellets, sawdust, wood chips, grain, paper trim, pet food, and countless others. They range from small and light to larger, heavier and more abrasive. AirPro has been innovating based on customer input and building industrial material handling fans for years with increasing efficiency and durability. Learn More
Centrifugal exhaust fans frequently process saturated air, meaning there is moisture from humidity or various gasses in the air. These applications often require heavier duty materials like stainless steel and moisture-resistant coatings like epoxy. When we engineer custom fans, we start with an appropriate fan type and tweak the materials, finishes and other specifications. Learn More
Many industrial processes rely on high-temperature process heat. Operations like heat treating, stress relieving, industrial furnaces and ovens use convection to circulate heated air within the chamber. These process airstreams require specially designed centrifugal fans. Fans not properly designed for this purpose will catastrophically fail when used at temperatures above their design. Learn More
Industrial fans need to meet a specific set of design criteria. We recommend working with an AirPro fan selection expert to design the best fan for your application. You will be working with industry-leading fan engineers to create customizable solutions to match your project requirements and budgets.
To view a full list of centrifugal fan applications, click here.
Centrifugal Fan Types
Common categories for impellers include forward or backward curved impellers, backward inclined impellers, and flat paddle wheel style impellers. They all have their own unique performance characteristics. AirPro offers a comprehensive selection of centrifugal fan designs including:
- Backward Curved
- Backward Inclined
- Forward Curved
- High Pressure
- High-Temperature Plug
- Industrial Exhaust
- Paddle Wheel
- Radial Tip
Safety & Maintenance
Safety and reliability are key areas of importance, and we guarantee our quality. AirPro inspects, tests, and engineers its industrial centrifugal fans to meet the highest levels of quality and safety. AWS standard certification and Quality Control documentation accompany every shipment. Our products are also CE Certified and ATEX rated.
Proper maintenance is critical to the successful operation and long fan life. In every possible case, our centrifugal fans contain features that make routine maintenance easy. To accommodate gases or materials in the airstream, add protection and increase the life of the blowers, we add special finishes including industrial enamel, specialty paints, powder coating, and custom linings.
Centrifugal Fans vs. Axial Fans
Industrial environments commonly use centrifugal fans and axial fans, but they have very different performance characteristics.
Axial fans serve applications requiring a large flow rate with a 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, we often see axial fans 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), primarily for process industries (petrochemical, oil refining, and gas compression).
- Forced ventilation systems.
Centrifugal fans typically work 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.