Centrifugal fans are widely used across industrial and commercial environments because of their ability to generate consistent airflow and handle higher static pressure than axial fans. Their design allows them to move air through ducts, filters, and resistance-heavy systems while maintaining stable performance.
At Aad Tech, we work extensively with forward-curved, backwards-curved, and EC centrifugal fans for HVAC and AHU retrofits. Each fan type offers a unique combination of airflow characteristics, efficiency, and application suitability.
The overview below highlights these centrifugal fan types and where they perform best.
Comparison Table: Types of Centrifugal Fans
| Fan Type | Key Characteristics | Typical Applications |
| Forward-Curved Centrifugal | High airflow at low static pressure; compact and quiet. | Commercial HVAC, AHUs, low-pressure duct systems. |
| Backward-Curved Centrifugal | Higher efficiency with better pressure handling. | Industrial AHUs, filtration units, high-resistance ventilation. |
| EC (Electronically Commutated) | High efficiency with variable speed control. | Retrofit projects, cleanrooms, data centers, energy-efficient HVAC. |
1. Forward-Curved Centrifugal Fans
Forward-curved centrifugal fans feature multiple short blades curved in the direction of rotation. They are designed to deliver high airflow at low static pressure, making them ideal for comfort cooling and low-resistance duct systems.
Typical Uses
- Commercial air handling units
- HVAC systems in offices, malls, and public buildings
- Ventilation systems requiring quiet operation
Their compact size and low-noise performance make them common in light commercial environments.
2. Backwards-Curved Centrifugal Fans
Backward-curved centrifugal fans have blades that curve against the direction of rotation. This design improves aerodynamic efficiency and enables the fan to handle higher static pressures, making it suitable for more demanding applications.
Typical Uses
- Industrial HVAC and AHUs
- Filtration and dust-control systems
- Ventilation systems with longer duct runs
- Medium- to high-pressure air movement
These fans offer strong, stable performance and are preferred where efficiency and reliability are essential.
Learn more about what happens when a centrifugal fan is wired backwards
3. EC (Electronically Commutated) Centrifugal Fans
EC centrifugal fans combine a centrifugal impeller with a high-efficiency EC motor. The built-in electronic control allows for variable speed adjustment, enabling the fan to modulate airflow based on system demand.
Typical Uses
- AHU retrofit projects
- Cleanrooms and pharmaceutical facilities
- Data centers and precision cooling
- Modern high-efficiency ventilation systems
EC fans offer improved energy savings, reduced noise, and better long-term operating performance.
Where Centrifugal Fans Are Commonly Used
The versatility of centrifugal fans allows them to support a wide range of applications:
Commercial
- Office HVAC
- Retail and hospitality
- Hospitals and healthcare ventilation
Industrial
- Manufacturing ventilation
- Filtration and dust management
- Clean-air supply in controlled environments
High-Efficiency Systems
- HVAC retrofits
- Cleanrooms
- Equipment cooling
Their consistent airflow and durability make centrifugal fans dependable for both everyday ventilation and specialized engineered systems.
Choosing the Right Centrifugal Fan
When selecting the appropriate fan type, the following factors should be evaluated:
- Required airflow (CFM)
- Static pressure and duct resistance
- Energy efficiency goals
- Noise limitations
- Filtration load
- Available installation space
Matching the fan design to system requirements ensures longer lifespan, stable operation, and reduced energy consumption.
Conclusion
Forward-curved, backwards-curved, and EC centrifugal fans each have their own strengths, making them suitable for different kinds of HVAC and ventilation systems. Understanding how these fan types behave under varying pressures and loads helps engineers and facility managers make informed decisions that improve performance and reduce operating costs.
At Aad Tech, we support businesses with fan selection, installation, and AHU retrofit services to help achieve better airflow, energy efficiency, and long-term system reliability.
Frequently Asked Questions
EC centrifugal fans, thanks to their variable speed control and high motor efficiency.
In commercial HVAC and AHUs with low-pressure airflow requirements.
Yes, especially in systems with filters or higher static pressure.
Yes, EC centrifugal fans are widely used in energy-efficient retrofits.
Yes, including selection, installation, and support services.