Backward curved, forward curved, double inlet, and plug fan solutions for AHU, cold chain, inverter cabinets, data center cooling, and industrial ventilation.
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Inside these downloadable PDF brochures, you will find precise aerodynamic performance curves (PQ curves), exact dimensional drawings, wiring diagrams, and acoustic data to help you select the optimal airflow solution for your HVAC or industrial project.
LONGWELL EC Double Inlet Forward Curved Centrifugal Fan, Double Inlet Blower Fan, 230V, for Cold Storage, Air Purifiers, HVAC Systems230 V1500 RPMECView & Inquire
LONGWELL EC Double Inlet Forward Curved Centrifugal Fan, Double Inlet Blower Fan, 230V, for Cold Storage, Air Purifiers, HVAC Systems230 V1500 RPMECView & Inquire
LONGWELL EC Double Inlet Forward Curved Centrifugal Fan, Double Inlet Blower Fan, 230V, for Industrial Ventilation, Cold Storage, Air Purifiers230 V1500 RPMECView & Inquire
LONGWELL EC Forward Curved Centrifugal Blower, Forward Curved Blower Fan, 110/230V 0–10V/PWM Control, PWM Control, for Fan Coil UnitsView & Inquire
LONGWELL EC Forward Curved Centrifugal Blower, Forward Curved Blower Fan, 230V, 80 W, for Range Hoods, Cold Storage, Air Purifiers4 in230 V4000 RPMView & Inquire
LONGWELL EC Gas Blower, Industrial Gas Blower Fan, 115V, 66 W, for Gas Transmission – LWGE097115V2600 rpmOtherView & Inquire
LONGWELL EC Gas Blower, Industrial Gas Blower Fan, 115V, for Boilers115V4000 RPMECView & Inquire
LONGWELL EC Gas Blower, Industrial Gas Blower Fan, 230V, 60 W, for Gas Transmission – LWGE077S-01230V10000 rpmOtherView & Inquire
LONGWELL EC Plug Fan, EC Centrifugal Blower Fan, 115V PWM Control, for AHU, Air Purifiers, HVAC Systems115V/220V/380V/4800V-50/60HzFREE STANDINGView & Inquire
LONGWELL EC Plug Fan, EC Centrifugal Blower Fan, 230V IP55, Stainless Steel, for AHU, FFU, Data Center Cooling230 V3500rpmECView & Inquire
LONGWELL EC Plug Fan, EC Centrifugal Blower Fan, 230V, 170 W, for AHU, FFU, Data Center Cooling – LWBE3G250-102PS-28133mm230 V3500rpmView & Inquire
LONGWELL EC Plug Fan, EC Centrifugal Blower Fan, 230V, Aluminum Alloy, for AHU, FFU, Data Center Cooling4 in230 V4000 RPMView & InquireEach document covers only the models listed in it; ISO certificates cover management systems, not products. Declaration of Conformity for your model and destination on request.
ISO 9001 · 14001 · 45001Management systems · 3 certificates · to Dec 2028
CE · LVD (2014/35/EU)KTS KB2206066L01 · listed LWBE3G models
ETL Recognized ComponentIntertek 5022563 · listed LWBE3G / LWDE3G / LWFE3G models
RoHS · (EU) 2015/863KTS KB2206068R01 · listed LWBE3G modelsSpecified and drawn by LONGWELL, built to our drawings by qualified partner factories, inspected and released to LONGWELL standards.
For more information, compare product specifications, applications, and get a quote for your unique requirements.
Longwell centrifugal fan consists of several primary components, including impeller, housing, inlet, and outlet. It is available in forward-curved, backward-curved, radial, and mixed-flow designs. Upon being powered on, the impeller begins to rotate; air is drawn in through the inlet, accelerated radially outward, and propelled in a circular motion at a steady, high velocity before finally being discharged through the outlet, thereby fulfilling the functions of ventilation, and heat dissipation.
Unlike axial fans—where air flows along the axis—the airflow in centrifugal fan, driven by the high-speed rotation of the impeller, exits in a direction perpendicular to the inlet. Consequently, it is capable of generating a more powerful and stable airflow.
Distinguished by its unique design, exceptional durability, and low noise levels, the centrifugal fan is ideally suited for applications requiring a wide range of airflow volumes and pressures. It is widely utilized across various sectors, including air pollution control systems, HVAC systems, pneumatic conveying systems, and industrial exhaust systems.
Explore our best-selling centrifugal fan models for HVAC, industrial ventilation, air handling units, refrigeration, combustion systems and OEM applications. Longwell offers AC, EC and DC centrifugal fans with high efficiency, low noise and custom manufacturing support.
Equipped with highly integrated external-rotor EC motor, Longwell centrifugal fans achieve the energy conversion efficiency of 80% to 90%.
High-quality raw materials and rigorous testing ensure a long service life for the centrifugal fan, as well as an ingress protection rating of up to IP55.
Longwell possesses highly flexible OEM/ODM manufacturing capabilities, covering impeller diameters ranging from φ133 mm to φ1000 mm.
Our extensive variety of centrifugal fans meets all your industrial ventilation needs, providing you with the most professional solutions.
When electricity is processed, stored and used, heat is generated that has to be dissipated. Longwell’s range of fans offers compact solutions for this with complete power density—and in a way that ensures powerful protection against environmental influences together with unbeatable quietness.
Longwell centrifugal fans convert incoming air velocity into pressure, delivering powerful airflow for HVAC, dust collection, and industrial ventilation. Their backward or forward curved impellers are engineered for optimized performance and minimal noise.
Designed with robust construction and precise dynamic balancing, Longwell centrifugal fans ensure stable operation and superior efficiency. They are perfect for cleanroom systems, manufacturing plants, and environments requiring reliable airflow under varying pressures.
Powered by Longwell’s SmartEC™ platform and optimized through AcousticFlow™ and AcuFlow™ technologies, our centrifugal fans deliver exceptional efficiency, quieter operation, and stable airflow characteristics. The optional ThermoFlex™ architecture further extends performance in extreme temperature conditions, making them suitable for a wide range of HVAC and industrial ventilation applications.
☑ AC Centrifugal Fans
☑ DC Centrifugal Fans
☑ EC Centrifugal Fans
Longwell offers a range of centrifugal fans engineered for various industrial applications. The following table provides a detailed comparison of the different types of centrifugal fans:
Type | Voltage Range | Max Airflow (CFM) | Noise (dB) | Typical Applications |
DC Centrifugal | 12-48V DC | 2000 | 45-50 | Data centers, Medical devices |
EC Centrifugal | 24-240V | 5000 | 50-55 | Factory ventilation, Clean rooms |
AC Centrifugal | 110-220V | 8000 | 55-65 | Heavy machinery, High-temperature environments |
Centrifugal fans are mainly powered by 3 types of motors—AC, DC, and EC—which drive the impeller’s rotation either directly or via transmission mechanism, thereby generating centrifugal force.
After entering the fan housing axially, the air accelerates radially outward under the influence of this centrifugal force and is subsequently discharged through the outlet. During this process, mechanical energy is converted first into kinetic energy and then into pressure energy.
The faster the impeller rotates, the greater the centrifugal force generated, resulting in higher air velocity. This type of fan is well-suited for duct systems that require a change in airflow direction, and it operates with high efficiency even when facing significant static pressure.
○ Airflow: 50 m³/h – 50,000+ m³/h
○ Static Pressure: 150 Pa – 3,000+ Pa
○ Speed: 900 RPM – 4,500 RPM
○ Voltage (DC): 12V, 24V, 48V, 72V
○ Voltage (AC/EC): Single-phase 115V/230V, Three-phase 380V/480V
○ Power Input: 10 W – 15+ kW
○ Impeller Diameter: Φ133 mm – Φ1,000+ mm
○ Noise Level: 45 dB(A) – 85+ dB(A)
○ Operating Temp.: -25°C to +60°C (Up to +85°C in exceptional cases)
○ IP Rating: IP44, IP54, IP55 (Selected explosion-proof/waterproof models up to IP68)
Centrifugal fans can provide a stable large air volume and high static pressure, ensuring that cold/warm air can overcome dense coil tubes, surface coolers, filters and long building air duct networks, and be evenly delivered to every corner of the building.
Scroll-less centrifugal fans equipped with intelligent EC motors are widely deployed in CRAC/CRAH units and on the air-cooled side of liquid cooling systems, effectively mitigating the array of issues associated with rapidly rising thermal densities in server rooms.
In the semiconductor manufacturing, pharmaceutical, and high-end medical laboratory sectors, high-efficiency centrifugal fans are integrated into Fan Filter Units (FFUs) to propel air through highly dense HEPA/ULPA filters by virtue of their robust static pressure capabilities.
The custom-made industrial centrifugal fans can generate extremely high system negative pressure, effectively removing polluted air from the working area and sending it into purification system, enabling enterprises to meet strict environmental protection emission standards.
Centrifugal fans featuring anti-corrosion coatings, explosion-proof motors, and explosion-proof impellers are capable of safely and continuously extracting hazardous media from environments such as welding workshops, chemical plants, and large-scale commercial kitchens.
In food processing, wood drying, paper manufacturing and spray curing processes, centrifugal fans equipped with extended shafts, cooling fans or insulation layers are able to withstand high temperatures, can accelerate the forced convection circulation of hot or cold air.
Centrifugal fans supply industrial boilers, incinerators, and kilns with precisely metered oxygen, while simultaneously utilizing high negative pressure to extract high-temperature exhaust gases generated during combustion, thereby maximizing thermal energy conversion efficiency.
Centrifugal fans are often used as high-pressure air pumps. They transport bulk solid materials at high speed through the pipeline, effectively preventing the materials from depositing or getting clogged in the conveying pipeline, and achieving fully enclosed and automated material circulation.
The centrifugal fans designed for heavy steel structure welding can provide massive air displacement and ultra-high wind pressure, effectively diluting and discharging toxic gases and high-concentration dust, thereby ensuring safety in deep-level operations within heavy industrial sectors.
In modern smart greenhouses and large-scale livestock farms, centrifugal fans are utilized to precisely regulate indoor temperature and humidity levels, as well as to exhaust ammonia gas. Furthermore, in large grain silos, high-pressure centrifugal fans are deployed for grain ventilation and moisture control, ensuring the long-term, safe storage of agricultural crops.
This entirely depends on your equipment’s internal resistance (system backpressure).
If your unit is compact and the airflow path is relatively unobstructed (like standard ventilators or low-pressure coils), a forward-curved impeller delivers a massive volume of air at lower speeds, with a softer acoustic profile.
However, if your system involves high-density HEPA filters, long and complex ductwork, or high-density server racks, go with a backward-curved impeller without hesitation. These fans are true “bulldozers”—they push through extremely high static pressure without a drop in airflow.
More importantly, backward-curved fans feature a “non-overloading” design. Even if system resistance suddenly drops, the motor won’t draw excessive current and burn out, making them ideal for rigorous industrial environments.
While the initial procurement cost of an EC (Electronically Commutated) fan is higher than a traditional AC fan, the payback period in commercial and 24/7 industrial applications is typically only 12 to 18 months.
First, the energy savings are massive. EC motors integrate an intelligent conversion module that completely eliminates the slip losses of traditional AC motors, achieving an overall efficiency of 80%-90%. This easily meets the most stringent European ErP 2015 directives.
Second, the control system is vastly simplified. To regulate the speed of a traditional AC fan, you need an expensive and bulky Variable Frequency Drive (VFD). In contrast, our EC fans come with a built-in control board.
You simply provide a 0-10V analog signal or PWM pulse for seamless, stepless speed control, which integrates effortlessly with your existing BMS (Building Management System).
Vibration doesn’t just generate noise; it drastically reduces the motor bearing’s lifespan (L10 life). We don’t rely on “assembly feel”; we rely on hard data.
Before assembly, every single centrifugal impeller—whether metal or fiberglass-reinforced plastic (PA66+GF30)—undergoes rigorous multi-plane dynamic balancing on specialized equipment. We strictly adhere to the international ISO 1940 standard, keeping residual unbalance strictly within the G6.3 grade (limiting eccentric vibration velocity to under 6.3 mm/s).
For medical devices or semiconductor cleanrooms with ultra-strict acoustic and micro-vibration requirements, we can even provide custom G2.5 high-precision balancing.
Absolutely. As a direct-to-factory manufacturer with comprehensive R&D and production lines, our response time for custom integration far exceeds that of pure trading companies.
Electrically, whether you need 12V/24V/48V DC fans for telecom base stations or wide-voltage commercial models (e.g., 200V-277V) for global compatibility, we can match the exact stator winding solutions.
Structurally, if you need to modify the scroll housing’s exhaust flange dimensions, customize mounting bracket holes, or change the impeller material for specific corrosive environments, our engineering team can interface directly with your R&D department’s CAD drawings, rapidly output 3D models, and arrange prototyping.
B2B procurement demands rigor, so we highly recommend—even require—our clients to conduct sample testing before committing to bulk orders.
Once your initial technical requirements (such as PQ performance curves and dimensional constraints) are confirmed, we can usually provide prototypes for your unit testing within 7 to 15 business days.
After you complete your thermal and acoustic testing and lock in the BOM (Bill of Materials), our standard bulk lead time is tightly controlled at 25 to 35 days. Thanks to our mature supply chain and robust production capacity, even large-volume orders during peak seasons won’t cause delays on your assembly line.
Motorized impellers are available in sizes 133 to 630 in combination with all motor sizes up to motor size 218. In addition to an inlet ring, an appropriately dimensioned motor mount must be provided on site to operate a motor-impeller.
LONGWELL Backward centrifugal fan with a support bracket are also available in sizes 250 to 560 in all impeller/motor combinations as ready-to-install support struts for wall mounting.The support bracket design includes the motor-impeller, a welded support strut design, an inlet ring and a square mounting plate.
LONGWELL EC centrifugal fan with a cube design with impeller diameters 310 to 560mm and the large size 218 motor are only available in the cube design intended for floor mounting.The struts are extruded aluminum profiles, the corner joints are made of die-cast galvanized metal sheet, and the motor mounting plate, inlet ring and nozzle plate are made of galvanized sheet steel.Bye the way ,this version is not suitable for wall mounting
FanGrid modules are made of few quantities of LONGWELL EC centrifugal fans with a support bracket in a special cube design.The pre-assembled units in sizes 355 to 560 were designed for setting up the FanGrid .They are suitable for applications with very high volumes of air that cannot be achieved by a single fan with the required compact design.
Ventilating large buildings efficiently – with ready-to-install EC Plug fans .
Backward centrifugal fan (standard version)
centrifugal fans with mounting bracket(V.0)
Centriifugal fans with mountingbracket(V.1)
| Diameter of Impeller (mm): | 133.175.190…450.500.560.630mm | ||||
| Air pressure ( static pressure): | up to 2200Pa(maximum) | ||||
| Air flow (m³/h）: | 200-23896 m³/h | ||||
| Power consumption (W): | 30-5955W | ||||
| Sound power (dBA): | 86 dBA(maximum) | ||||
| Blade Material: | PA666+FG (133..400mm) ; Galvanized (250mm); Aluminum Alloy (310…630mm) | ||||
| Electrical connections EC Technical features ： |
| ||||
| Model no. | Diameter | Maxi Airflow | Max Static Pressure | Power Input | Protection Class |
| Unit | (mm) | (m³/h) | (Pa) | (W) | |
| LWBE3G EC FAN | 133,175,190,225,250 | 260-2900 | up to 1500 | 30-750W | IP44 / IP54 / IP55 |
| LWBE3G EC Plenum fan | 280,310.355,400,450 | 3700-9200 | up to 3270 | 170-4200W | IP44 / IP54 / IP55 |
| LWBE3G High pressure Centrifugal fan | 500,560,630 | 15000-23200 | up to 1920 | 1250-5600W | IP44 / IP54 |
| Test stand design and tests in accordance with ISO 5801 – Industrial fans, performance measurement on standardized test stands DIN EN ISO 3744, DIN EN ISO 3745, ISO 13347-3 – Acoustics standards Measurement quantities and measurement accuracies attained with the aero-acoustic test stand. | |||||
High-performance impeller
GreenTech EC motor
High-performance impeller
Electronics and connection
Cost comparison
Energy Consumption Comparison (Before vs. After Retrofit)
Comprehensive Retrofit Comparison (Multi-Dimensional)
As the characteristics of high air volume and wide coverage of static pressure in the field of ventilation, EC rear tilt centrifugal fans are widely used in HVAC, refrigeration, heating, ventilation equipment, purifiers, clean rooms, FFU, AHU, precision air conditioning and other applications, the highest air volume up to 24000m³/h, the highest static pressure up to 3270Pa. It is highly customizable and can be customized according to the actual working conditions of customers
With a maximum static pressure of 2300 Pa, the fan satisfies the high-resistance demands of AHU applications. A single fan can deliver up to 6 kW of power and a maximum airflow of 23,000 m³/h. Additionally, for industrial applications, a fan wall combination option is available, providing flexible solutions to meet diverse application requirements. The energy loss, high maintenance costs, and potential stability issues associated with traditional belt-driven fans in AHUs can be effectively addressed through our fan wall retrofit solution. Compared to conventional forward belt-driven fans, the upgraded fan wall can improve efficiency by 20% to 50%.
Backward-curved centrifugal fans are revolutionizing air purification in residential and commercial settings, delivering unmatched efficiency, quiet operation, and reliability. Designed for optimal air circulation and filtration, these fans excel in air purifiers by leveraging their aerodynamic design—curved blades that minimize turbulence, reduce energy consumption, and maximize air volume under high static pressure (ideal for dense filter media).High-Efficiency Airflow: Generate consistent, high-volume airflow (up to 500+ CFM) while maintaining energy efficiency (10–30% less power than traditional fans), ensuring rapid air turnover for HEPA/activated carbon filters.
As the demands for commercial and industrial environments increase, the performance requirements for HVAC equipment have become more stringent. Our fans must be able to achieve precise control of temperature and humidity with 100% accuracy. Additionally, there is growing concern about fan energy consumption, maintenance costs, and noise pollution.
To meet the airflow and efficiency requirements of data centers, a 630 medium static pressure high-efficiency fan series has been specifically developed. This series is designed to provide optimal performance, balancing airflow demands with energy efficiency, making it ideal for data center applications.
For FFU (Fan Filter Unit) applications, which require high efficiency, low noise, and stable group control in medium to low static pressure environments, two highly efficient fan models, have been specifically developed. These models are tailored to meet the unique demands of FFU systems, ensuring optimal performance in such scenarios.
Impeller sizes ranging from 310 to 630mm are available to fit different installation spaces, and standard mounting brackets can be selected for quick and convenient installation.Can be combined into a fan wall to achieve greater airflow.EC/DC/AC motors can be selected to match different equipment power requirements.Customizable to meet specific application needs, such as C5 corrosion protection, IP56 protection rating, and operation at temperatures as low as -30°C.
Salt mist test assesses the corrosion resistance of the LONGWELL fan, especially under C5-grade corrosion conditions. It ensures long-term performance in salty environments, providing protective measures for aluminum-magnesium alloy impellers against corrosion.
This test evaluates the operational stability of the fan under rapid temperature changes. The high-temperature materials and precise control system of the LONGWELL fan ensure that performance is not affected by thermal expansion and contraction under extreme temperature variations.
This test measures the airflow output and fan efficiency under different speeds and static pressure resistance. The optimized impeller design and threedimensional blade structure of the LONGWELL fan ensure efficient airflow output and adaptability to various working conditions.
This test validates the fan’s durability in harsh outdoor environments. The LONGWELL fan’s IP55/IP56 protection rating, along with its high-temperature and corrosion-resistant design, ensures reliable long-term operation outdoors.
This test evaluates the long-term lifespan of the fan in standard indoor environments, ensuring that the LONGWELL fan has a long life with low maintenance requirements. The test is particularly focused on its performance in common applications such as AHU and FFU systems.
This test validates the reliable operation of the LONGWELL fan in hightemperature environments, especially under high static pressure and efficient electromagnetic design conditions. It ensures the stability of the impeller material at extreme temperatures, extending the fan's lifespan.
This test validates the fan's performance stability in environments with varying temperature and humidity, particularly in corrosion and moisture-resistant conditions. A 21-day continuous operation at 75°C and 95% humidity is used to verify the fan’s long-term stability
The Water Droplet Spray Test is a critical evaluation for ventilation fans, designed to simulate operational exposure to moisture-laden environments (e.g., humidity, light rain, or condensation). This test ensures fan components—including motors, bearings, electrical systems, and structural materials—maintain corrosion resistance, electrical integrity, and functional reliability under prolonged moisture contact.
The Aging Test evaluates ventilation fans’ long-term durability and reliability by simulating extended operational cycles and environmental stresses (e.g., temperature fluctuations, humidity, vibration, and dust). This accelerated assessment ensures fans maintain structural integrity, performance efficiency, and safety compliance throughout their designed lifecycle.
The Runout Test is a critical quality control procedure for centrifugal fans, measuring rotational alignment (radial/axial runout) of impellers, shafts, and bearings. By quantifying deviations from perfect concentricity, this test ensures fans operate with minimal vibration, noise, and mechanical stress—key to optimizing performance, durability, and safety.
This test focuses on verifying the strength and stability of the LONGWELL fan’s impeller under long-term high-speed operation and ensures that the impeller remains free from deformation or damage under highspeed conditions, ensuring the fan's safety and reliability, especially in applications requiring high-efficiency airflow output.
This test verifies the low noise performance of the fan at high speeds and high static pressure, analyzing noise through FFT noise spectrum analysis. The optimized flow path and blade design effectively reduce noise levels, improving the overall comfort of the operating environment. It minimizes the transmission of low-frequency noise over long distances in ventilation ducts.
When selecting a fan for a specific application, these parameters play an important role:
Electronic / Thermal protection for this product
EC motor : Control input 0-10VDC/PWM, Tech output, Locked-Rotor
protection, Reverse Polarity,
Over-voltage protection, Soft Start Protection(Delay time <35 seconds to full speed)
Information on motor protection and thermal protection is provided in product-specific data sheets.
The following protection methods are provided depending on the type of motor and area of application:
– Thermal overload protector, in-circuit or external ;
– PTC with electronic diagnostics;
– Impedance protection ;
– Thermal overload protector with electronic diagnostics ;
– Current limitation via electronics ;
If use is made of an external thermal overload protector, a commercially available tripping unit must be connected by the customer for shut-off. Motor protection conforming to the applicable standard must be fitted for products not provided with a built-in thermal overload protector and not protected against improper use.
Lifespan of this product :40,000 hours （EC MOTOR with ball bearings) , 30,000 hours (AC MOTOR with ball bearings)
The service life of the bearing system is primarily governed by the thermal load on the bearings. For the majority of our products, we use maintenance-free ball bearings which can be fitted in any installation position. Sleeve bearings can alternatively be employed, as described in product-specific data sheets.
As a rough guide (depending on the general conditions), the ball bearings have a life expectancy L10 of approx. 40,000 hours of operation at an ambient temperature of 40 °C. We will gladly provide you with a life expectancy calculation based on your specific usage conditions.
Fan connection modes vary according to different voltages and operating conditions (such as speed regulation requirements). Draw a connection diagram based on the fan configuration in use. The following shows two common EC centrifugal fan motor connection modes for reference only. Specific project requirements can be connected with our company’s sales engineers
The centrifugal air gap between the inlet nozzle and impeller cover plateinfluences the air performance and efficiency of the centrifugal fan.
Effects of installation spaceWhen mounting our product in a rectangular box, air performancemight be reduced.
dh= Hydraulic diameter
Formula: dh=2xB xH/(B + H)
B= Width of box
H= Height of box
D= Outer diameter of the fan
Airflow determination for inlet rings with pressuretap:
The differential pressure method compares the static pressureupstream ofthe inlet ring with the static pressure in the inlet ringThe airfow can be calculated from the differential pressure (bet.ween the static pressures) according to the following equation:
