Backward Inclined Fans
Efficient Industrial Air Movement Solutions
Backward inclined centrifugal fans provide a proven balance between high efficiency, robustness, and light dust handling capability.
Featuring solid, backward-inclined blades that slope away from the direction of rotation, these fans deliver stable, non-overloading performance while remaining more tolerant of dry, mildly contaminated air than airfoil designs.
Industrial Fan Systems backward inclined centrifugal fans are engineered, tested, and supplied for demanding Australian and New Zealand industrial environments. ISO 5801 performance tested and built for long service life, these fans are widely selected for HVAC, process ventilation, aspiration, combustion air, and dust filtration applications where efficiency and reliability must coexist.
Backward Inclined Centrifugal Fans – Efficient Industrial Air Movement Solutions
What Is a Backward Inclined Centrifugal Fan?
A backward inclined centrifugal fan uses solid blades that are inclined away from the direction of rotation. This blade geometry reduces aerodynamic drag, delivers high static efficiency, and produces a non-overloading power curve similar to airfoil fans, while offering greater resistance to dust buildup and blade fouling.
Backward inclined fans are particularly well suited to clean to lightly contaminated air streams where airfoil fans may be unsuitable due to erosion or clogging risk, but where heavy-duty radial or paddle wheel fans are not required.
Why Choose a Backward Inclined Fan?
Advantages
Backward inclined centrifugal fans are selected when applications demand efficiency, operational stability, and tolerance to light dust.
Key Advantages:
High Static Efficiency: Efficient airflow delivery across a broad operating range
Non-Overloading Power Curve: Protects motors and electrical systems
Light Dust Handling Capability: Suitable for dry, mildly contaminated air streams
Lower Noise Levels: Quieter than radial and paddle wheel fan designs
Robust Blade Construction: Solid blades resist erosion and fouling
These characteristics make backward inclined fans a versatile choice for many industrial ventilation systems.
Key Features & Engineering Benefits
Backward Inclined Impeller Design: Aerodynamically engineered solid blades incline away from the direction of rotation, combining high efficiency with improved resistance to dust accumulation compared to airfoil blades.
Energy-Efficient Operation: Backward inclined fans maintain stable efficiency across varying airflow conditions and operate on a non-overloading curve, reducing the risk of motor overload and improving long-term reliability.
Durable Industrial Construction: Manufactured from carbon steel, stainless steel, or alloy materials, Industrial Fan Systems backward inclined fans are designed for longevity in harsh industrial environments. Protective coatings are available for corrosive or high-temperature applications.
Dry Dust Handling Capability: Backward inclined fans are well suited to aspiration, filtration, and process ventilation systems handling clean to lightly contaminated air, where airfoil fans may be vulnerable to fouling.
Flexible Drive & Mounting Options: Available in direct drive or belt drive configurations, with horizontal or vertical mounting options to suit system layout and maintenance requirements.
Performance Range &
Technical Specifications
Airflow
Up to 55m3/s (SWSI) and
100 m3/s (DWDI)
Impeller Diameter
310mm to 2495mm
Model Range
IFSBL-115 to IFSBL-245
Static Pressure
Up to 5,000 Pa
Arrangement Options
SWSI: Arrangements 1, 3, 4, 4F, 7, 8, 9
DWDI: Arrangements 3, 7
Configurations
SWSI (Single Width Single Inlet) and
DWDI (Double Width Double Inlet)
Impeller Type Comparison Table
Backward inclined fans occupy the ideal middle ground between high-efficiency airfoil fans and heavy-duty radial or paddle wheel designs.
SWSI & DWDI Configurations
SWSI (Single Width Single Inlet)
Suitable for moderate airflow
and higher pressure applications
where installation space is
limited and flexibility in
arrangements is required.
DWDI (Double Width Double Inlet)
Designed for higher airflow duties,
commonly used in large ventilation
systems and air handling units where
footprint and arrangement options
are less constrained. Industrial Fan
Systems provides engineering support
to ensure the correct configuration is
selected for each application.
Industrial Fan Systems provides engineering support to select the optimal configuration for your system.
Technical Information
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Fully welded impellers manufactured to precise tolerances
Dynamic balancing to ANSI/AMCA 204 standards
Fully welded fan housings with external bracing where required
Precision-machined EN8-grade steel shafts
Spherical roller bearings in grease-lubricated pillow block housings
Multiple shaft seal options for light duty to airtight applications
Structural channel bases with optional anti-vibration mounts
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Industrial Fan Systems backward inclined fans can be customised to suit specific operating requirements:
Split housings for maintenance access
High-temperature construction for furnaces, kilns, and dryers
Spark-resistant designs to AMCA classifications
Inlet boxes for improved airflow stability
Discharge cowls for weather protection and airflow control
Inlet and outlet dampers
Flexible bellows for vibration isolation
Vibration and temperature monitoring sensors
Inlet and outlet silencers (attenuators)
Surface protection coatings for corrosive environments
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Backward inclined centrifugal fans are widely used in:
Aspiration and dust filtration systems
Boilers, kilns, and combustion air systems
Process cooling and ventilation
Fume extraction systems
HVAC supply, return, and exhaust air systems
Mining and quarry ventilation
Food and pharmaceutical processing with light dust
Industries & Applications
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HVAC
HVAC ventilation that improves airflow, reduces energy use, and supports optimal indoor air quality efficiently.
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Industrial Processes
Control heat, dust, fumes, and boost energy efficiency across manufacturing operations.
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Mining & Smelting
Provides underground ventilation, dust control, and gas dilution, ensuring a safe environment for workers.
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Oil & Gas
Explosion-proof fans meeting ATEX/IECEx standards for use in hazardous areas.
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Recycling
Improve dust control, fume extraction, airflow efficiency, and ensure environmental compliance.
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Agriculture
Ensure climate control, humidity regulation, and air quality in barns, greenhouses, and storage facilities.
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Air Pollution Control
Customised designs for dust extraction, fume removal, VOC management, and emission control.
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Food & Beverage
Hygienically design fans for food processing, cold storage, and cleanrooms.
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Furnace & Oven
Ensure energy-efficient airflow, temperature control, and safety in kilns and furnaces.
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HVAC Systems
Reliable, energy-efficient fans for commercial and industrial HVAC applications.
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Manufacturing
Ensure reliable airflow, cooling, dust control, and energy-efficient operation in production facilities.
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Paper & Pulp
Industrial fans for paper and pulp mills, dust control, moisture management, and airflow for production & drying.
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Pharmaceuticals
Ensure air quality, filtration, and safety in controlled manufacturing environments.
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Spray Booths
Spray booth ventilation fans for fume extraction, overspray control, and odour removal.
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Tunnel Ventilation
Ensure efficient airflow and ventilation in mining, transport, and construction tunnels.
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Water Treatment
Ensure ventilation and airflow, odour control, corrosion resistance, and regulatory compliance.
Backward inclined centrifugal fans are selected when applications demand efficiency, operational stability, and tolerance to light dust.
Warranty & Support
We stand by the quality and reliability of our products, offering both performance and workmanship guarantees. Our guarantees cover 12 months of operation or 18 months from delivery, whichever occurs first, ensuring peace of mind and confidence in our engineering excellence.
Warranty
Comprehensive fan selection and system design support services to ensure optimal fan performance throughout its service life.
Support Services
Certifications &
Compliance
This ensures the product complies with international standards for performance, quality, and safety.
ISO 9001
(Quality Management Systems)
ISO 14001
(Environmental Management Systems)
ISO 45001
(Occupational Health & Safety)
Why Choose Industrial Fan Systems?
Industrial Fan Systems combines proven aerodynamic design with Australian‑based engineering expertise. Our airfoil centrifugal fans are selected, tested, and supported to perform reliably in real‑world industrial environments.
ISO 5801 tested performance data
ISO13347-3:2004 for sound
Engineered for Australian and New Zealand conditions
Application‑specific fan selection support
On-site support
Ready to improve your industrial ventilation and reduce operating costs?
Our Products
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![Airfoil Centrifugal Fans]()
Airfoil Centrifugal Fans
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![Industrial-Fan-Systems-IFS-Products-PW-Paddle-Bladed-Centrifugal-Fans]()
Paddle Bladed Centrifugal Fans
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![Industrial-Fan-Systems-IFS-Products-Backward-Curved-Centrifugal-Fans]()
Backward Curved Centrifugal Fans
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Radial Bladed Fans
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Radial Tip Fans
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High Pressure Fans
Frequently Asked Questions
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Airfoil fans offer slightly higher efficiency but require clean air. Backward inclined fans retain high efficiency while offering improved tolerance to light, dry dust.
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Yes, they are commonly used for dry, light dust applications such as aspiration and filtration systems.
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No. Backward inclined fans operate on a non-overloading power curve, protecting motors from overload.
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Yes. Spark-resistant and ATEX / IECEx compliant configurations are available.