AHU | FCU | FFU | Cooling Tower
Proventofan manufactures EC centrifugal and axial fans from 133mm to 630mm. Lower energy use than fixed-speed AC in variable-airflow systems, with 0–10V and PWM control built in and Modbus RS485 available. CE certified. OEM supply to 25+ countries. Standard samples in 3–7 days.
Most EC fan delays don't come from the fan itself. They come from a control question nobody asked until after the airflow number was already locked.
Cause
A request often arrives as “quote me a fan” with an airflow number attached. That number describes the duty. It says nothing about how the fan will actually be commanded once it's wired into a PLC or BMS.
Solution
Control compatibility is the real gate, not an afterthought. Can the PLC write speed directly? Is there a hard limit on max RPM? Does it need 4-20mA or 0-10V? What happens if communication drops? Get these answered before the airflow number gets locked, not after.
Engineering case note
In one transformer-cooling integration project, the selected fan and controller configuration supported standard Modbus RS485 with no proprietary software, configurable maximum RPM, direct 4-20mA acceptance, status feedback registers, and defined behavior on communication loss.
EC stands for electronically commutated. AC mains power goes in, a built-in controller converts it, and a brushless DC motor drives the impeller. A separate inverter or VFD is normally not required. Send a 0–10V or PWM signal and the fan adjusts speed on its own. That is the difference between EC and a standard AC fan with a bolt-on speed controller.
The controller is integrated into the motor housing. There is no separate VFD or inverter to install, wire or maintain. Control signals connect directly: 0–10V, PWM or Modbus RS485.
EC motors hold their efficiency across a wide speed range. In HVAC most systems run at partial load most of the time, and that is exactly where the difference shows up on the energy bill.
Output adjusts to actual demand. In variable-airflow AHU and FCU systems, reducing fan speed can substantially lower power consumption compared with continuous full-speed operation. Actual savings depend on the baseline fan, duty cycle, control strategy, and system resistance.
Side-by-side comparison: EC vs AC →
Comparison
AC, DC and EC fans differ in how they take power in and how they control speed. That difference, not a simple efficiency ranking, decides which motor type actually fits a given system.
Wire an AC fan straight to mains power and it spins at one speed, sometimes two if the motor has a pole change winding. Many AC induction fans need external speed-control hardware such as a VFD for variable speed, which takes panel space and adds another point of failure. But AC is the option every electrician already knows, and that familiarity keeps installed cost low.
Full EC vs AC comparison →DC fans need a DC power supply, typically 12V to 48V and up to 110V on larger frames. They are common in telecom, server and battery-powered equipment, and Proventofan DC axial and centrifugal fans go up to 450mm. The choice usually comes down to whether the system has a suitable DC supply, plus the airflow, pressure and control the application needs.
DC fan selection guide →Many AC fans need an external VFD for speed control. DC needs a DC power supply. An EC fan splits the difference: mains AC power goes in, and a brushless DC motor with a built-in controller handles the rest. Send it a BMS signal and speed follows on its own. That combination is why EC is a common choice for AHU, FCU and FFU retrofits, covered in detail throughout this page.
Try the tool
Check whether your BMS, PLC or relay output can drive an EC fan via 0–10V, PWM or Modbus RS485. Get wiring and alarm notes in seconds.
EC fans come in three main configurations. The right one depends on your duct layout and static pressure requirement. Axial and centrifugal describe the airflow path; a plug fan is a centrifugal impeller supplied without its own housing for direct plenum mounting.
An EC axial fan moves air parallel to the shaft, which gives high volume at low static pressure. Common diameters run from 200mm to 630mm. Typical uses include HVAC air handling units, refrigeration condenser sections, data center in-row cooling, and general industrial ventilation.
Browse EC axial fans →
A housed EC centrifugal fan draws air in axially and discharges it radially through a scroll casing. That produces higher static pressure at moderate volume, which fits ducted systems with filters, coils, and long duct runs. Common uses include ducted HVAC air handling units, fan coil units, energy recovery ventilators, and clean room supply systems.
Browse centrifugal blowers →
A plug fan is a centrifugal impeller and motor supplied without a scroll casing. It installs directly inside an AHU plenum chamber, positioned so the impeller draws air through the coil section and discharges it into the supply plenum. Without a scroll casing, it can integrate efficiently into a properly designed AHU plenum while eliminating belts and pulleys. Final efficiency and noise depend on the impeller, inlet conditions, operating point, and plenum design.
Browse EC centrifugal fans →Selection Guide
Use the table below as a starting point to match your application, typical static pressure, and install context to an EC fan type.
| Application | Typical External Static Pressure | Install Context | Specify |
|---|---|---|---|
| Condenser coil cooling | 0-120 Pa | Open air, rack | EC Axial |
| In-row server cooling | 0-150 Pa | Data center row | EC Axial |
| General industrial ventilation | 50-200 Pa | Open or lightly ducted | EC Axial |
| Ducted FCU / ERV | 150-400 Pa | Ducted with filter and coil | EC Centrifugal |
| AHU with scroll housing | 200-600 Pa | Ducted AHU, new build | EC Centrifugal |
| Clean room supply | 400-800 Pa | Precision pressure control | EC Centrifugal |
| AHU plenum retrofit | 200-700 Pa | Inside existing plenum | EC Plug Fan |
| Belt-drive AHU fan retrofit | 300-600 Pa | Existing AHU plenum; mounting and airflow path must be reassessed | EC Plug Fan or Fan Array |
| Large commercial AHU | 250-600 Pa | Free plenum space | EC Plug Fan |
These pressure ranges are preliminary selection guides, not fixed limits. Final fan selection must be based on the required airflow at the actual external static pressure, plus impeller, frame size, and operating point.
Proventofan EC fans go into four main HVAC applications: air handling units, fan coil units, fan filter units and cooling towers. Each section below lists the models that fit, with actual specs and links to the product pages.
Scene 01
Air handling units run continuously in commercial buildings, shopping centers and hospitals. Fan energy can be a significant part of AHU operating energy. EC fans connect to a BMS via 0–10V signal or Modbus RS485, so speed follows actual demand rather than running flat out around the clock.
EC Fan Models
Scene 02
Fan coil units live inside hotel rooms, apartment ceilings and office corridors. Quiet matters more than most engineers plan for. The FC3E133 draws just 18W at full speed, and the room thermostat can turn it down for quieter operation. At 44W, the FC3E175PN230-76 fits slightly larger cabinets.
EC Fan Models
Scene 03
Pressure drops as clean room filters clog. A fixed-speed AC fan just delivers less and less air, and nobody notices until the ISO class slips. With airflow or pressure feedback, an FFU controller or BMS can command the FC3E225 and FC3E250 to speed up and keep airflow on target between filter changes.
EC Fan Models
Scene 04
Cooling towers push a lot of air at very low pressure. The F3E300 axial handles standard fan decks at 230V. For larger induced-draft towers, the FC3E560 steps up to 380V and 2,000W power rating. Both take a 0–10V signal, so speed comes down in mild weather instead of pushing flat out all year.
EC Fan Models
Try the tool
Enter your required airflow, static pressure and voltage to find the right EC fan frame size for your application.
Try the tool
Convert fan airflow between m³/h and CFM instantly, then check the result against Proventofan's published EC fan airflow ratings.
Most AC centrifugal fans in HVAC applications run at fixed speed. On a mild day that means full power regardless of what the building actually needs. Adding a VFD fixes the speed problem but brings extra cost, wiring and one more device to service.
EC fans remove all of that. The controller is built into the motor housing. Send a 0–10V signal from the BMS and the fan adjusts on its own. In many cases the existing mounting position can be reused; confirm the mounting dimensions first.
| Frame Size | EC Replacement Model | Power | Voltage | Typical Application |
|---|---|---|---|---|
| 133mm | FC3E133PN230-50 | 18W | 230V | FCU, small AHU |
| 175mm | FC3E175PN230-76 | 44W | 230V | FCU, medium AHU |
| 190mm | FC3E190PN230-70 | 85W | 230V | AHU |
| 225mm | FC3E225PN230-70 | 120W | 230V | FFU, AHU |
| 250mm | FC3E250PN230-90 | 220W | 230V | FFU, AHU |
| 310mm | FC3E310AN230-20L | 396W | 230V | AHU, commercial HVAC |
| 400mm | FC3E400AN380-80 | 2,000W | 380V | Large AHU |
| 560mm | FC3E560AN380-80 | 2,000W | 380V | Large AHU, cooling tower |
Planning an actual swap rather than sizing a new unit? A matching frame is not an automatic drop-in. Our AC fan to EC fan replacement guide walks through the six checks and when an EC fan is not a drop-in.
Send us the frame size, voltage and current power draw. We will confirm the right EC replacement and estimated energy saving. We respond within 1 business day.
Try the tool
Enter your current AC fan dimensions and voltage to check whether an EC replacement is feasible and see which frame sizes match.
Fixed-speed AC fans draw close to the same power at 2am as they do at peak load. EC fans do not. Speed follows demand, and the saving shows up fastest on circuits that run the longest hours. The ranges below come from the same load model our engineering team uses when quoting a retrofit.
~50%
Typical Energy Saved
AHU duty cycles swing hard between morning startup and afternoon peak. An EC fan follows that curve in real time, so the motor is not pulling full power during the quiet hours.
~50%
Typical Energy Saved
Most FCU circuits still run on a single fixed speed, even though occupancy on any floor changes hour to hour. EC lets the fan drop toward idle the moment a room empties out.
~40%
Typical Energy Saved
FFU circuits in a clean room run nonstop, so even a small cut in required airflow shows up directly in the power bill. EC fans hold that lower draw around the clock, not just for one shift.
~35%
Typical Energy Saved
Cooling tower demand tracks outside air temperature, not a fixed schedule. On a mild day the fan can sit well below full output, and an EC motor is built to do exactly that on its own.
~30%
Typical Energy Saved
Cabinet cooling tends to run at a fairly steady load to begin with. That is why the saving lands lower here than AHU or FCU, not because the fan does less work, just because there is less swing to capture.
These are typical ranges from our engineering load model, not measured results from one site. Actual savings depend on operating hours, load profile and control method.
Need a number that accounts for control method and load profile too? Full calculator →
Want an engineering-checked number instead of an estimate? Send us your fan size and current power draw. We will run it for you. We respond within 1 business day. Get an estimate →
Try the tool
Model payback period and net savings for an AHU retrofit project. Enter fan counts, power data and project cost to see your ROI timeline.
133mm to 630mm, centrifugal and axial. FCU, FFU, AHU and cooling tower applications covered from a single source. No need to split an order across suppliers to cover the full size range.
EC motors hold their efficiency across a wide speed range. At partial load, which is most of the time in HVAC, that shows up on the energy meter every month.
0–10V and PWM are standard across the EC range, with Modbus RS485 available as a configurable option on the FC3E centrifugal series. No separate VFD or signal converter required. Connect the BMS directly and the fan handles the rest.
All EC fans carry CE certification. Every EC fan is manufactured in our ISO 9001-certified facility. CE documentation is confirmed with the quotation.
Standard catalog samples ship in 3–7 days. OEM custom samples take 5–10 days; volume orders run 15–20 days for standard models and 18–25 days for OEM builds. Fully custom frame sizes go through a separate quote for tooling lead time.
We supply OEM and ODM to HVAC manufacturers, system integrators and equipment builders across 25+ countries. NDA and white-label supply are available for OEM orders; CE documentation is confirmed with the quotation.
Following a balancing issue identified during a customer's first trial order, we reviewed both the allowable correction weight and our final-speed test procedure. We then introduced a hard cap on balancing correction and changed final inspection to a full-speed run, helping us identify abnormal vibration before shipment.
Try the tool
Compare total cost of ownership over 3, 5 or 10 years. Include purchase price, energy cost and maintenance to see which fan type is cheaper for your project.
There is no single savings percentage that applies to every installation. EC fans can substantially reduce fan energy in variable-airflow systems, particularly when the original AC fan runs continuously at full speed. Actual savings depend on the baseline motor and fan efficiency, operating hours, duty cycle, control strategy, and system resistance. Under ideal fan-law conditions, a fan operating at 70% speed requires approximately 34% of its full-speed power, but whole-system savings must be calculated from the actual duty profile.
Normally not. The speed controller is built into the motor housing. Connect a 0–10V or PWM signal directly from your BMS and the fan adjusts on its own, so a separate VFD or inverter is normally not required.
0–10V DC and PWM are standard across the FC3E centrifugal range; Modbus RS485 is standard from 220mm up and available as an option on smaller sizes. Modbus RS485 lets you read speed, power draw and fault status back to the BMS as well as send speed commands, which makes fault logging and energy monitoring possible without adding separate metering hardware. 4-20mA is available as a custom configuration for specific projects.
In many cases yes. EC centrifugal fans are offered in common frame sizes from 133mm to 560mm, and many replacements can reuse the existing mounting position once the mounting dimensions are confirmed. The main new element is wiring: a low-voltage control signal alongside the mains supply. If you are running 133mm to 225mm fans in FCU or FFU cabinets, the swap is often straightforward.
That said, a matching frame is not an automatic drop-in. Confirm voltage and phase, control signal, airflow, static pressure, IP rating and ambient temperature first. See when an EC fan is not a drop-in replacement for the full gate.
All EC fans carry CE certification. Every EC fan is manufactured in our ISO 9001-certified facility. CE test reports and declaration of conformity documents are confirmed with the quotation.
Standard catalog samples ship in 3–7 days. OEM custom samples take 5–10 days; volume orders run 15–20 days for standard models and 18–25 days for OEM builds. We respond to inquiries within 1 business day. Fully custom frame sizes go through a separate quote for tooling lead time.
Sample orders start at 1 unit. Standard catalog orders have a MOQ starting from 10 pieces; OEM custom-specification and private-label orders have a MOQ of 50 pieces. Send us the spec and we respond within 1 business day.
Yes. White-label packaging, custom labeling and NDA agreements are available for OEM orders. We supply to HVAC manufacturers and system integrators in 25+ countries. If you need a specific label, box design or documentation set, let us know at the quoting stage.
An EC fan uses a brushless motor with integrated electronics that control motor commutation and speed. In AC-input models, the onboard electronics convert the incoming power before driving the motor. Depending on the model, speed can be controlled through 0-10V or PWM as standard, Modbus for two-way digital communication, or 4-20mA as a custom option for specific projects. Because the drive electronics are integrated into the fan, a separate VFD is normally not required.