AC Centrifugal Fan: Backward Curved, 133mm–372mm, 115V to 400V
Proventofan's AC centrifugal fan range uses a backward-curved impeller for higher static-pressure headroom and a non-overloading power curve. Direct AC operation, with single-speed and selected tapped-speed variants: nothing extra to spec into the build or troubleshoot later.
Twelve frame sizes from 133mm to 372mm, also listed as an AC centrifugal blower in some documentation (same product, same specs). Every model uses a backward-curved impeller and connects directly to your AC mains supply; there's no separate control electronics in the build to size or wire in. 115V, 230V and 380V cover most frame sizes. The 315mm and 355mm frames include dual-voltage three-phase options, while the 325mm frame is also available in a 400V version. Several sizes are also available in 2-speed or 3-speed variants, noted on the card where it applies. Full per-model, per-voltage data is in the Specs table below.
Match voltage to what your installation already supplies. For the same model variant at the same frequency, equivalent voltage versions are designed for comparable airflow and pressure. Frequency and speed-tap configuration are what actually change performance, not voltage alone. Then confirm your operating point: maximum airflow and maximum static pressure occur at different points on the fan curve and can't be hit at the same time. Request the performance curve or contact us to confirm your specific point.
Wondering how a speed or voltage change would shift these numbers? Our Fan Laws Calculator works through the airflow, pressure and power relationships behind a change like that.
Published insulation resistance exceeds 200MΩ. IP44 protection against solid objects larger than 1 mm and splashing water, and built-in automatic thermal protection, are available across the listed range. On the FC2A and FC4A series, the fan resumes operation on its own once it cools; no manual reset required.
Peak Performance by Frame Size — 14 Frame/Depth Groups
Each row is a distinct physical frame size and depth. Expand a row to see every published voltage, frequency and speed-tap variant for that size, drawn from Proventofan's verified model data.
Per-voltage, per-frequency figures aren't individually published for this single-speed configuration in Proventofan's spec data. The 56–64W / 2,500–2,900 RPM range shown above is the manufacturer's combined 60Hz peak across all three listed voltages (590 m³/h, 370 Pa). Contact us to confirm the exact figure for a specific voltage.
Per-voltage, per-frequency figures aren't individually published for this single-speed configuration in Proventofan's spec data. The 63–73W / 2,500–2,700 RPM range shown above is the manufacturer's combined 60Hz peak across all three listed voltages (620 m³/h, 420 Pa). Contact us to confirm the exact figure for a specific voltage.
Per-voltage, per-frequency figures aren't individually published for this single-speed configuration in Proventofan's spec data. The 93–122W / 2,600–2,900 RPM range shown above is the manufacturer's combined 60Hz peak across all three listed voltages (980 m³/h, 550 Pa). Contact us to confirm the exact figure for a specific voltage.
Per-voltage, per-frequency figures aren't individually published for this configuration in Proventofan's spec data. The 119–180W / 2,650–2,950 RPM range shown above is the manufacturer's combined 60Hz peak across all three listed voltages (1,340 m³/h, 730 Pa — the highest static pressure in the range). Contact us to confirm the exact figure for a specific voltage.
Per-voltage, per-frequency figures aren't individually published for this configuration in Proventofan's spec data. The 116–173W / 2,650–2,950 RPM range shown above is the manufacturer's combined 60Hz peak across all three listed voltages (1,350 m³/h, 580 Pa). Contact us to confirm the exact figure for a specific voltage.
Per-voltage, per-frequency figures aren't individually published for this configuration in Proventofan's spec data. The 101–170W / 1,380–1,560 RPM range shown above is the manufacturer's combined 60Hz peak across all four listed voltage options (2,380 m³/h, 400 Pa). Contact us to confirm the exact figure for a specific voltage.
Per-voltage, per-frequency figures aren't individually published for this configuration in Proventofan's spec data. The 170–248W / 1,380–1,550 RPM range shown above is the manufacturer's combined 60Hz peak across all listed voltage options (2,900 m³/h, 530 Pa). Contact us to confirm the exact figure for a specific voltage.
φ355 × 13060Hz2301501,5502,900530
Variant
Voltage
Freq
Current (A)
Power (W)
Speed (RPM)
Airflow (m³/h)
Static Pressure (Pa)
Noise (dB)
Capacitor
Single-speed (230V only)
230V
50Hz
0.55
110
1,350
2,550
390
66
3.0/450V
Single-speed (230V only)
230V
60Hz
0.67
150
1,550
2,900
530
69
3.0/450V
φ372 × 190 "-2"50Hz only115 / 2301961,3603,300450
Variant
Voltage
Freq
Current (A)
Power (W)
Speed (RPM)
Airflow (m³/h)
Static Pressure (Pa)
Noise (dB)
Capacitor
Model "-2" (50Hz only)
115V
50Hz
1.81
196
1,360
3,300
450
72
20/250V
Model "-2" (50Hz only)
230V
50Hz
0.91
196
1,360
3,300
450
72
5/450V
φ372 × 190 "-3"60Hz115 / 2302841,5603,810580
Variant
Voltage
Freq
Current (A)
Power (W)
Speed (RPM)
Airflow (m³/h)
Static Pressure (Pa)
Noise (dB)
Capacitor
Model "-3" (50/60Hz)
115V
50Hz
2.00
206
1,380
3,360
450
72
20/250V
Model "-3" (50/60Hz)
115V
60Hz
1.50
284
1,560
3,810
580
75
20/250V
Model "-3" (50/60Hz)
230V
50Hz
0.98
206
1,380
3,360
450
72
6.0/450V
Model "-3" (50/60Hz)
230V
60Hz
1.24
284
1,560
3,810
580
75
6.0/450V
How to Read This Table
Most sizes are available at both 50Hz and 60Hz; the frequency shown above is the peak figure for that row, and every Power/Speed/Airflow/Pressure value in that row comes from that same frequency only.
None of these are 50/60Hz figures blended together.
The φ372×190 "-2" model is 50Hz only, so its number above isn't a 60Hz figure like the rest of the table, which is why it's called out separately.
φ355mm and φ372mm each list two rows because they're two distinct real depths/models at the same diameter, not two data points for one product; see the Products section above for how each is represented on a single card.
Full per-frequency breakdown is in the expandable rows above.
Container & Freight
Order quantity affects your per-unit freight cost: more units per container means a lower landed cost per fan. Exact container fit depends on frame size and packaging, so we confirm it for your specific model and order quantity at quotation rather than publishing one number that wouldn't apply across twelve different frame sizes.
Operating Point
Airflow and static pressure figures are peak values at the frequency and voltage shown. Actual performance at your installation's operating point will be lower than the free-air peak; request the performance curve to confirm.
04 / APPLICATIONS
Where AC Centrifugal Fans Are Used
HVAC Centrifugal Fan for Air Handling Units
AHUs push air through coils, filters and long duct runs before it reaches the room, and that resistance is exactly what a backward-curved impeller is built to hold against. Fixed-airflow, fixed-speed AHU duty is where an AC centrifugal fan earns its keep, since there's no drive electronics in the build to size, wire or troubleshoot. AHUs that need VAV, 0–10V control or BMS-tracked load instead call for an EC centrifugal fan; see our EC centrifugal fan range
For buyers specifying an HVAC centrifugal fan for an air handling unit, 115V, 230V and 380V options cover a range of regional power-supply requirements, including single- and three-phase setups, without a separate conversion stage.
Appliance & Equipment OEM Integration
When an OEM engineering team needs to qualify a second source or cross-reference an existing fan, the match has to hold on airflow and power draw at the real operating point, not just frame size. We've matched a 250mm AC centrifugal fan to a 530–590 CFM target for a major appliance manufacturer's cross-reference brief, and validated a 315mm sample against an equipment manufacturer's mechanical and electrical acceptance criteria before a production order.
Engineering test samples ship ahead of any commitment, so your team can confirm fit before requalifying the rest of the assembly.
High Static Pressure & Ducted Airflow Systems
Within the AC line, static pressure capability varies by frame size. The 225mm model has the highest published maximum static pressure in the range, 730 Pa; actual airflow against your system's resistance comes from the performance curve. That pressure capability is what lets these fans keep moving air through tight enclosures, filtered airstreams or long duct runs where an axial fan's output would fall off fast.
That headroom is why AC centrifugal fans turn up in places most people wouldn't think to look for them, from sub-slab depressurization ductwork to filtered process air. Anywhere the path air has to travel is the harder part of the job, not the open room at the end of it.
The listed AC centrifugal fan range carries CE marking. Certificate of Origin, test reports and Certificate of Conformity can be provided on request; ask at quotation and we'll confirm what applies to your specific model and destination market.
Standard export documentation ships as one package: commercial invoice and CE Declaration of Conformity sent together, prepared before shipment when requested at quotation, rather than chased down from separate desks after your shipment has already left.
Quality control runs three checkpoints: incoming inspection (IQC) on raw materials and purchased components before production; in-process inspection (DUPRO) partway through the run to catch process drift before a full batch is affected; and 100% pre-shipment inspection (PSI) on the finished lot before release.
Quality Control — Three Checkpoints
IQC Incoming Quality InspectionDUPRO Motor WindingDUPRO Dynamic Balancing TestDUPRO Performance Test BenchPSI Outgoing Inspection & Packing
06 / ENGINEERING VALIDATION
Engineering Validation in Practice
01
We Verify Every Symptom Separately, Not Just the Headline Complaint
A returned batch with mixed symptoms (slow-running units, abnormal noise, high vibration, one dead on arrival) gets checked symptom by symptom against its own root cause, not collapsed into one investigation. On one 190mm batch, four symptoms traced to four separate causes: a reversed motor lead, a misaligned terminal-board pillar, shipping-damaged impellers, and a loose connection at the customer's own installation. Two of the three "high vibration" units retested within our 1,000 µm/s limit on our own test bench.
02
We Trace a Fault to Its Actual Source Before Assuming a Manufacturing Defect
When a fan fails after installation, we check whether the cause traces to manufacturing or to what happened after the fan left our factory. An oversized mounting screw or a nicked lead wire during panel-building can produce the same symptoms as a winding fault. On one case, teardown found both causes were installation-stage, not manufacturing, and we still marked safe screw depth directly on the housing so it's easier to avoid next time.
03
We Turn a Flagged Sample Concern Into a Documented Production Spec
A sample that passes mechanical and electrical acceptance can still carry something worth confirming: a slight wobble, a noise level. When a customer flagged that on an otherwise-passing 315mm sample batch, we moved that account's wobble check from sampling to every unit before packing, and added pallet packing for the volume order. That's a specification for the run, not a complaint managed away.
04
We Confirm Certification Coverage and Prepare Documents Before You Have to Chase Them
Which CE declarations apply to your model, and when documents ship, gets confirmed at quotation, not after goods have shipped. On a multi-model order, we stated which CE declarations applied per model and sent the commercial invoice and CE documents together, prepared ahead of the customer needing to ask twice. AC centrifugal models across the range carry the same CE coverage.
07 / ENGINEER'S NOTE
From the Test Bench
Custom engineering build — not a catalogue rating. The data below comes from a 355mm test build developed for a specific customer project. It does not represent the catalogue φ355×162 or φ355×130 models listed in the Specs table above — the numbers here describe that custom build only.
A Motor Rework That Measurably Helped — With a 50Hz Tradeoff
On this 355mm/115V test build, a motor rework that redesigned the winding and increased the start capacitor from 12µF to 40µF brought a real, measured improvement at 60Hz: winding temperature rise dropped from 63°C to 43.1°C in a formal sample inspection, while power eased from 405W to 380W and speed ticked up from 1,670 to 1,690 RPM.
The same rework didn't repeat at 50Hz. Temperature rise there moved from 41.2°C to 47°C, worse rather than better, at slightly higher power for the same 1,440 RPM. If your application runs 50Hz, that tradeoff is part of the real picture, not a footnote we'd rather leave out.
Temp. Rise (°C)
60Hz · Before · 12µF63°C
60Hz · After · 40µF43.1°C
50Hz · Before · 12µF41.2°C
50Hz · After · 40µF47°C
Frequency
Build
Capacitor
Power (W)
Speed (RPM)
Temp. Rise (°C)
60Hz
Before
12µF
405
1,670
63
60Hz
After
40µF
380
1,690
43.1
50Hz
Before
12µF
240
1,440
41.2
50Hz
After
40µF
261
1,440
47
08 / OEM SUPPORT
Custom AC Centrifugal Fans for OEM Buyers
Commercial Terms
We build to your spec. What changes determines the path:
01
Stock fan, your logo
No added fee or lead time on standard models, subject to model and order requirements.
02
Custom impeller colour or spec, on an existing or shared mould
Fee and lead time quoted case by case.
03
A new mould built specifically for your design (private tooling)
30–40 days to build the mould; fee quoted case by case.
Private moulds (tooling built exclusively for your design) are paid for by the customer. For volume orders above 1,000 pcs, tooling can be amortized into the unit price. Standard or shared moulds carry no tooling fee; that cost is on us. Send your voltage, impeller material, speed-tap or private-label requirement and we'll confirm which path applies before quoting.
What voltages are available for AC centrifugal fans?
Most frame sizes ship in 115V, 230V and 380V. The 315mm and 355mm frames add a 230–400V dual-voltage three-phase option, and the 325mm frame is also available in a 400V version. Confirm exact voltage coverage for your frame size at quotation, since not every size covers all voltages.
What's the difference between AC, DC and EC centrifugal fans?
AC centrifugal fans connect directly to an AC mains supply, with no control electronics built in to spec or troubleshoot. DC centrifugal fans connect to a DC bus (24V/48V/85V/110V) with built-in PWM or 0–10V speed control. EC centrifugal fans combine an AC supply with an internal electronically-commutated drive for variable-speed operation and BMS integration. See the full DC centrifugal fan range or EC centrifugal fan range.
Are your AC centrifugal fans backward curved?
Yes. Every frame size in the AC centrifugal range uses a backward-curved impeller, which holds airflow better against static pressure than a forward-curved design and gives the fan a non-overloading power characteristic.
Do your AC centrifugal fans carry CE marking?
Yes. The listed AC centrifugal fan range carries CE marking. Certificate of Origin, test reports and Certificate of Conformity can be provided on request; confirm what your shipment needs at quotation.
Can you supply a custom voltage or frame size?
Yes. Modifications on an existing or shared mould (custom voltage, impeller colour, spec changes) are quoted case by case with no tooling fee. A fully custom frame on a new, private mould takes 30–40 days to tool and is quoted separately.
What's the difference between 115V, 230V and 380V AC centrifugal fans?
For the same model variant at the same frequency, equivalent voltage versions are designed for comparable airflow and pressure. Frequency and speed-tap configuration are what actually change performance. Match the voltage to what your installation already supplies.
What's a Good HVAC Centrifugal Fan for Air Handling Units?
An AC centrifugal fan is the standard choice for fixed-airflow, fixed-speed AHU duty, where a backward-curved impeller holds airflow against the resistance of coils, filters and duct runs. For AHUs needing VAV, 0–10V control or BMS-tracked load, see our EC centrifugal fan range.
What's the sample lead time for AC centrifugal fans?
Standard catalogue samples ship in 3–7 days. Custom builds on an existing or shared mould are quoted case by case; a new private mould adds 30–40 days for tooling before the first sample can run.
Who pays for custom tooling or moulds?
It depends on whether the mould is private or shared. Custom impeller colours or spec changes made on an existing or shared mould carry no tooling fee; that cost is on us. A brand-new mould built specifically for your design is private tooling, and the customer covers that cost; it's quoted case by case alongside the 30–40 day build time.
What documents come with my order, and when?
Commercial invoice and CE Declaration of Conformity ship as one package, prepared before shipment when requested at quotation rather than chased down from separate desks after your shipment has left. Certificate of Origin, test reports and Certificate of Conformity can be added to the package if specified at quotation.
Fig. 01Backward Curvedφ133–372mm115–400V
