Factory-direct EC centrifugal fans and blowers from 133mm to 560mm: 230V single-phase from 133mm to 450mm, and 380V three-phase from 280mm to 560mm. Backward-curved and backward-inclined impeller configurations, brushless EC motor, speed control built in. No external VFD to wire up.
13 frame sizes from 133mm to 560mm. Impeller options span plastic, galvanized steel and aluminum alloy, depending on frame size and duty. Speed control is available as PWM, 0–10V or Modbus RS485.
All 13 frame sizes carry CE marking. Peak airflow and peak pressure may come from different model variants within the same frame size. They should not be read as a single operating point. Check the performance curve for final selection.
Every stage inside an air handling unit adds resistance before the air leaves the unit — coil banks, filter racks, mixing dampers, then the duct run itself. That’s why AHU fan selection is a static-pressure problem, not just an airflow one. A centrifugal impeller takes air in axially and discharges it radially, and this fan type is available at substantially higher static-pressure duty points than our EC axial range. Once the required operating point moves beyond the pressure capability of an axial fan, centrifugal becomes the more appropriate starting point for selection.
Fan Coil Units
FCUs combine a coil, filter and compact air path in a limited enclosure, so the fan has to overcome a defined pressure drop rather than simply move free air. A centrifugal blower’s radial discharge can also suit FCU layouts where the airflow must turn into a short duct or outlet path after passing through the coil and filter. The actual choice still comes back to the required airflow and static pressure at the operating point.
FFU & Clean Rooms
A fan filter unit (FFU) pushes air through a HEPA or ULPA filter, and that filter creates a pressure drop that increases as loading builds. Centrifugal fans are commonly used where the required FFU duty point calls for more static-pressure capability than an axial arrangement can provide. On models equipped with Modbus RS485, the fan can also be integrated into a BMS or networked speed-control architecture rather than adjusted unit by unit.
High-Backpressure Cooling: Data Centers, Cooling Towers & Condensers
Condenser coils, dense coil banks and some cooling tower configurations create real resistance to airflow. Where the required duty point sits beyond an axial fan’s pressure range, or where the installation needs a ducted or radial-discharge arrangement, centrifugal can be the better fit. Large-volume, straight-through installations at lower static pressure (including many mechanical-draft cooling towers) are often better served by axial fans. Cooling-tower fill media by itself is not a reason to choose centrifugal; check the actual airflow, static pressure and installation geometry.
These are four representative installation patterns. For a broader breakdown by industry and airflow requirement, visit the EC Fan Solutions page.
04 / SPECIFICATIONS
EC Centrifugal Fan Specifications
The table below shows the peak values across every variant we build in each frame size: max airflow, max static pressure, and the power/noise range you’ll see across that size’s speed options. Two fans at the same diameter can draw very different power depending on which speed variant you pick, so treat this table as “what’s possible at this size,” not “what one specific fan does.” For a single model’s exact numbers, use the selection guide or send us your operating point.
Read Before You Spec
Peak airflow and peak pressure may come from different model variants within the same frame size. They should not be read as a single operating point. Check the performance curve for final selection.
Speed control is available as PWM, 0–10V or Modbus RS485.
Grouped by shared performance curve, not flattened by SKU — models sharing one curve differ in speed, current draw or discharge orientation. 26 curve groups, 55 published electrical variants across 13 frame sizes. Click a frame size to expand.
Impeller material varies by series: GN = galvanized steel, PN = plastic. -90 and -96 share identical published performance; they are two SKUs that differ in body height.
This section covers wiring for the BLEC72, BLEC92, BLEC102, BLEC137 and BLEC188 motor variants. Check the Motor column in your model’s spec table above, then match it to the correct diagram below. BLEC102 wiring varies by voltage and control interface; BLEC137 and BLEC188 share the same wiring diagram.
EC stands for electronically commutated: a brushless permanent-magnet motor with the drive electronics built into the housing. PWM and 0–10V speed control are available across the catalog range, with Modbus RS485 available on selected models. These control methods do not require an external VFD. For the full mechanism, see What Is an EC Motor?
02
What Makes It Centrifugal: The Impeller
What makes it a centrifugal fan is the impeller: air enters along the shaft and is discharged outward, radially. The catalog includes backward-curved and backward-inclined configurations depending on model. Depending on how the fan is installed, that airflow may discharge into a scroll housing or directly into an AHU casing or plenum. What defines the centrifugal arrangement here is the radial impeller flow path, not the presence of a scroll.
03
Non-Overloading Power
The backward-swept impeller designs used in this range have a non-overloading power characteristic: required power reaches a maximum within the operating range instead of continuing to rise toward free delivery. Forward-curved fans can show increasing power demand at higher airflow, so motor selection has to allow for that overload risk. This non-overloading characteristic is one reason backward-curved and backward-inclined designs are widely used in AHU, plenum and duct-connected systems.
04
EC Plug Fan: A Naming Note
In some project specs, the same product appears as an EC plug fan — that describes an unhoused installation, not a different motor technology. Instead of discharging into a dedicated scroll housing, the impeller operates directly in the AHU casing or plenum.
Not every project calls for an EC motor. The centrifugal fan guide puts AC, EC and DC side by side with real selection criteria: airflow range, static pressure, supply voltage and operating environment. If you’re still unsure which type fits after reading the specs above, that page will give you a clearer answer. View Centrifugal Fan Guide
Quick Selection Guide
01
133mm – 225mm
230V. Fan coil units, small AHU, ventilation cabinets. Plastic impeller. PWM or 0–10V control (Modbus RS485 also available from 220mm).
02
250mm – 310mm
230V (250mm) or 230V/380V (280mm–310mm). Mid-range AHU and rooftop units. Plastic, galvanized or aluminum alloy impeller options across this range. IP44 at 250–280mm; 310mm is available in IP44/IP54. Modbus RS485 available across this range.
03
355mm – 450mm
230V or 380V. Commercial AHU, cooling towers, large FCU. Aluminum alloy impeller. IP54 rated. Modbus RS485 available across this range.
04
500mm – 560mm
380V only. Industrial ventilation, data center cooling, process air. Aluminum alloy. IP54. PWM / 0–10V / Modbus RS485.
Already know your airflow and static pressure?
Use the EC Centrifugal Fan Selector to screen specific FC3E catalog models by voltage, control interface and frame size. Final model selection still requires a fan-curve check.
Check the EC Fan Replacement Selector — enter your current fan’s specs and it flags whether a direct swap looks likely, needs confirmation, or needs an engineering check.
Not integrated; the compatible external control method depends on motor and supply configuration
Integrated PWM / 0–10V; Modbus RS485 on 220mm and larger
Part-Load Energy
Power falls when fan speed is actually reduced with a compatible controller; fixed-speed operation does not capture that saving
Variable-speed control is integrated; under the affinity laws, 80% fan speed corresponds to about 51% of full-speed shaft power under ideal similar-system conditions
Control Hardware
Separate controller/drive and associated power/control hardware where variable speed is required
Drive electronics are integrated into the fan
Power Input
115V / 230V / 380V / 400V AC, model-dependent
230V / 380V AC, model-dependent
AC fans cost less upfront. The comparison changes when the application needs variable airflow: a compatible AC solution then needs external control hardware, while EC already integrates the drive electronics. EC is usually the stronger fit when BMS integration or long part-load operation matters. For fixed-speed applications with limited annual runtime, AC can still be the more economical choice.
Check what’s already in your equipment. Choose DC if you’ve already got a 24V, 48V, 85V or 110V supply running: the fan connects straight to it and you’re not paying for a conversion stage you don’t need. Choose EC if you don’t have that DC supply on hand: it runs from the mains AC already available at the panel, with no separate AC–DC power module to specify.
Comparing all three side by side? See the full technology matrix on the Centrifugal Fan page
08 / CENTRIFUGAL VS AXIAL
EC Centrifugal vs EC Axial: Which One Fits Your System?
Two questions decide it, not brand preference or diameter alone.
01
How Much Static Pressure Do You Need?
EC axial fans in our range reach roughly 135–300 Pa across the 200mm–630mm size range. That can be enough for open discharge and some lightly restricted systems, but it may be insufficient once the combined coil, filter and duct resistance pushes the required duty point above that range. EC centrifugal fans start higher (a 133mm centrifugal reaches 433 Pa) and the catalog range reaches 1,520 Pa. If the required operating point sits beyond the pressure capability of the axial range, move to centrifugal rather than trying to recover pressure simply by oversizing the axial fan.
02
How Does the Fan Need to Discharge?
Axial fans move air straight through, in line with the motor shaft: the right geometry for open panel mounts, many cooling tower installations, or other straight-through airflow paths. Centrifugal fans take air in axially and discharge it radially, which suits layouts where the airflow must turn into a plenum or duct path, including many AHU, FCU and FFU arrangements.
Quick answer
Straight-through discharge at lower static pressure → EC axial fan. Higher-pressure or radial-discharge duty point → EC centrifugal (this page). Check the actual airflow and static pressure numbers rather than assuming the application decides it.
One first-order risk we’ve seen firsthand is a gap between the condition validated during production and the condition the customer actually runs at.
Trial-Run Specs Can Introduce Risk Standard Production Doesn’t Have
Risk
A first trial order built to a tighter spec than the standard catalog part (lower noise, a tighter tolerance or another customization) can change the production process behind it. If that change is not bounded and verified at the actual operating condition, a deviation that a reduced-speed test misses can reach the customer’s incoming inspection.
Confirm
Ask whether your requirement changes anything in the standard build or test process, and whether that change has been verified at full operating conditions rather than only at a reduced test step.
Our Response
After catching this exact failure mode on a trial build, we tightened the process limits and added full-operating-speed verification before shipment for the affected balancing process.
10 / CERTIFICATION & QUALITY CONTROL
Certification & Quality Control
Certification Coverage
CE — Standard on Every EC Centrifugal Fan
Every EC centrifugal fan carries CE marking as standard. We hold the certificate but do not publish the number on this page. Applicable CE documentation is confirmed at quotation stage and can be supplied with the order. For multi-model orders, we identify which declaration applies to each ordered model rather than leaving the buyer to match documents after shipment.
Certification At a Glance
CE
Standard on every model
Documentation
Confirmed at quotation stage
Multi-Model Orders
Declaration matched per model
Quality Control
01
Incoming Materials (IQC)
Incoming materials and purchased components go through inspection before production starts.
02
In-Process Inspection (DUPRO)
In-process inspection at the 30% and 70% production marks catches process drift before a full batch is affected — covering motor winding and dynamic balancing.
03
Performance Test
Rotor and impeller balance is tested in-house to G2.5 as standard (G1 available for vibration-sensitive applications), alongside electrical and airflow performance verification.
04
Pre-Shipment Inspection (PSI) & Burn-In
The finished lot gets 100% pre-shipment inspection before release — not sampled. Burn-in aging testing is performed according to the product line and inspection plan, followed by a final packing check.
IQC IQC — Incoming InspectionDUPRO Motor WindingDUPRO Dynamic Balancing (G2.5)Performance Test Performance Test BenchPSI Outgoing Inspection & Packing (PSI)PSI Burn-In Aging Test
When a sample flags a specific issue such as noise or slight wobble, that check can be escalated from sampling to individual inspection for the account, and pallet packing can be added on larger orders to reduce transit-shock risk.
11 / OEM SUPPLY
Factory-Direct EC Centrifugal Fans for OEM Projects
We manufacture these fans at source, which means changes to the spec do not have to pass through a distributor first. If your AHU build needs a non-standard voltage, a different impeller material or your label on the motor housing, you are discussing the requirement directly with the manufacturing side.
Samples: no minimum order quantity. Bulk orders: 10 units minimum on standard catalog, 50 units on OEM custom builds. FOB Ningbo or FOB Shanghai. Payment terms are confirmed per order based on volume and history, not a fixed template. Warranty: 12 months from shipment.
Multi-Model Bulk Orders
For a complex multi-model bulk order, actual lead time can run longer than the single-model ranges above. We confirm the schedule against the real order mix rather than applying the shortest catalog lead time to every combination.
Spare Parts & Urgent Orders
Spare parts and small urgent orders receive the same first-reply priority as larger production inquiries: availability and lead time first, followed by a PI with courier-ready packing data where express shipment is involved, so the buyer’s shipping team can move without a second round of basic logistics questions.
Common Customizations
Voltage: 230V or 380V standard; other voltages on request
Impeller: plastic, galvanized steel, or aluminum alloy
Speed control: PWM / 0–10V / Modbus RS485
IP rating: IP44 or IP54
Shaft and flange dimensions to drawing
Private label and custom packaging
The voltage, control signal and impeller material splits shown in the Specs and Selection Guide sections above are the catalog configurations with real customer demand behind them — not the limit of what we can build. If your application needs something outside that list, send us the operating point and we will confirm feasibility and quote it.
EC stands for electronically commutated. The motor takes AC mains power and converts it internally for a brushless permanent-magnet motor and electronic commutation. The same integrated electronics handle speed control: PWM or 0–10V across the catalog range, with Modbus RS485 on 220mm and larger models. No external VFD is required.
What is the difference between an EC fan and an AC fan?
An AC centrifugal fan can also save power at part load if a compatible external controller actually reduces fan speed. Under the fan affinity laws, shaft power is approximately proportional to the cube of speed for similar operating conditions, so 80% speed corresponds to about 51% of full-speed shaft power in the ideal relationship; actual electrical savings also depend on the system curve and motor/drive efficiency. The practical EC difference is integration: the motor drive and speed-control electronics are built into the fan, so there is no external VFD or motor-drive package to specify for the EC fan. Variable-speed operation still requires a control signal from your own controller or BMS.
What is an EC plug fan?
EC plug fan describes an unhoused mounting arrangement, not a different motor type. Instead of discharging into a dedicated scroll housing, the impeller operates directly in the AHU casing or plenum. The term describes the installation arrangement rather than a separate motor technology.
What voltages are available for EC centrifugal fans?
230V single-phase is available from 133mm to 450mm, and 380V three-phase from 280mm to 560mm (500mm and 560mm are 380V only). If your project needs a voltage outside that range, send us the spec and we will confirm what is feasible for an OEM order.
Can EC centrifugal fans be used in AHU systems?
Yes. The 190mm–450mm range includes configurations suited to many AHU duty points, but selection should be made against the required airflow and static pressure rather than diameter alone. The fans accept 0–10V control, with Modbus RS485 also available. OEM custom builds run 5–10 days for samples and 18–25 days for bulk production.
Can you customize EC centrifugal fans for OEM orders?
Yes. Voltage, impeller material, IP rating, speed-control interface, connector type, mounting details and private labelling can be reviewed for OEM projects. Many requirements can be handled with existing platforms; if a change needs new tooling or engineering work, that is confirmed before quotation. Send a drawing, operating point or competitor part number and we will review it.
What’s the difference between an EC fan and a DC fan?
EC fans run on mains AC (230V or 380V) with the motor drive and speed control integrated. DC fans run on a low-voltage DC bus (24/48/85/110V). If the equipment already has a suitable DC bus, a DC fan can connect directly to it. If it does not, EC can simplify the power architecture because it runs from the mains supply without a separate AC–DC power module for the fan.
Fig. 01Brushless ECφ133–560mm230 / 380V AC
