What the OEM was building
A European OEM was building a new line of commercial ventilation products. They needed AC circular duct fans across every size in it.
Their enquiry mixed qualification with buying. In other words they wanted papers to approve us as a supplier, plus prices for pre-production batches.
Three requests in one
- First, drawings and specifications for a batch of a 250mm metal-bladed inline duct fan.
- Second, quotes and technical data for 100mm and 150mm PVC-housed fans, clearly a lower-cost variant in the same family.
- Third, and largest, a spread of metal impeller models from 100mm all the way to 315mm.
Quantities ran from ten to fifty units per model. Clearly that is prototype and first-build territory rather than volume production.
The fixed points
Everything had to run on 230V, 50Hz. Meanwhile all units needed CE certification for market access. Furthermore, the performance data had to stand up against ISO 5801, since their own product carried efficiency claims.
The shape of the request told its own story. An OEM asking for plastic and metal AC circular duct fans together, across five diameters, is building a family. Above all, they want one supplier to cover it.
Mapping the range onto our catalog
This was logged as light development, so the job was papers and prices rather than design. Consequently the engineering work lay in mapping their list onto proven catalog models.
Where plastic belongs
Firstly, the PVC-housed series covers the 100mm and 150mm sizes. Both housing and impeller are ABS, which keeps cost and weight down.
These suit general ventilation where static pressure stays modest. Certainly there is nothing second-rate about that choice, provided the duct run is short.
Where metal earns its price
Meanwhile the metal impeller series answers the harder end. A steel housing with a backward-curved wheel reaches 855 Pa in the 315mm model. Plastic simply cannot do that.
Furthermore it lasts longer in hard installations. That gave the customer a real high-performance option inside the same family.
We considered EC and left it alone
An EC platform came up in house, offering SmartEC speed control and better efficiency.
However, their request named standard AC circular duct fans throughout. That usually means outside speed control is already designed in, or the target market cares more about price. Either way, following the request mattered more than showing off a better motor.
What was delivered
Here the package held datasheets and CAD drawings for seven models, all approved under our ISO 9001 system. Consequently their engineers could qualify us and design the fans in during one pass.
Technical Specifications
Several AC circular duct fans appear below. Compare the power column against the airflow column, since that shows where each one belongs.
| Parameter | LWDA-100S-MBN-15-07 | LWDA-150S-MBN-12-07 | LWDA-200S-MBN-13-07 | LWDA-250(10″)S-MWN-06 | LWDA-315S-MBN-02-07 |
|---|---|---|---|---|---|
| Voltage (V) | 220 | 230 | 230 | 220 | 220 |
| Frequency (Hz) | 50 | 50 | 50 | 50 | 50 |
| Speed (RPM) | 2760 | 2160 | 2540 | 2800 | 2680 |
| Input Power (W) | 75 | 72 | 176 | 100 | 280 |
| Max Airflow (m³/h) | 258 | 457 | 987 | 2100 | 1236 |
| Max Airflow (CFM) | 152 | 272 | 580 | 1236 | 727 |
| Max Static Pressure (Pa) | 359 | 368 | 515 | ~350 (est. from curve) | 855 |
| Noise Level (dBA) | N/A | 61 | 70 | N/A | N/A |
| Impeller Diameter (mm) | 100 | 150 | 200 | 250 | 315 |
| Protection Class | IP44 | IP44 | IP44 | IP44 | IP44 |
| Insulation Class | Class F | Class F | Class F | Class F | Class F |
| Operating Temp (°C) | -25 to +60 | -25 to +60 | -25 to +60 | -25 to +60 | -25 to +60 |
| Life Expectancy (L10) | 40,000h @ 25°C | 40,000h @ 40°C | 40,000h @ 40°C | 40,000h @ 40°C | 40,000h @ 25°C |
| Certifications | CE, FCC | CE, FCC | CE, FCC | CE, FCC | CE, FCC |
Technical Documentation
The approved documents for each AC circular duct fan are listed below. Consequently the customer had drawings and datasheets in one package rather than in a chain of emails.
LWDA-100S-MBN-15-07 Spec Sheet: This datasheet provides the full electrical and aerodynamic performance data for the 100mm metal duct fan, essential for the design engineer.
LWD100(4″)-PWN-10 Drawing: This 2D drawing gives the critical dimensions for the 100mm PVC duct fan, which the procurement manager needs for fit-check and validation.
LWDA-150S-MBN-12-07 Spec Sheet: This file contains the performance curves and nominal data for the 150mm metal duct fan, used by the HVAC engineer to model system performance.
LWD150(6″)-PWN-09 Drawing: This is the dimensional drawing for the 150mm PVC fan variant, required by the mechanical integration team.
LWDA-200S-MBN-13-07 Spec Sheet: Performance data, including the P-Q curve and noise level, for the 200mm metal fan is detailed in this document.
LWDA-250(10″)S-MWN-06 Spec Sheet: The specification sheet for the 10-inch model outlines key parameters like its 2100 m³/h airflow for the system designer.
LWDA-315S-MBN-02-07 Spec Sheet: This document details the specifications for the most powerful fan in the request, capable of 855 Pa, critical for applications with high system resistance.
Why one supplier covered the whole family
Picking one supplier for a whole family of AC circular duct fans is a different decision from buying a single fan.
- One catalog covered everything. Altogether the request spanned seven models, two materials and five diameters. All of it came from our standard range, which spares the customer the work of managing several suppliers for a single product line.
- Documents that were already approved. Spec sheets and drawings went out immediately because they existed and were current. By contrast, the same paperwork from European sources can take weeks to assemble.
- Two price points on purpose. Offering the plastic series alongside the metal one let the OEM address two segments of their market from a single supplier. Making both ourselves is what made carrying two variants practical rather than expensive.
- Compliance in the package. Every datasheet carries the CE mark and references testing to AMCA 210/211 and ISO 5801. Furthermore our China-local TUV NORD relationship shortens the certification cycle for their finished units.
Browse the duct fan range, or the inline duct fan section. Airflow testing follows AMCA 210.
Questions about these fans
What bearings do the metal impeller fans use, and how long do they last?
Deep groove ball bearings throughout, all maintenance-free. Accordingly they are rated for 40,000 hours L10 at 25 to 40C and 15% to 65% relative humidity. In short, that construction is what suits the fit-and-forget installations commercial HVAC relies on.
Can these AC circular duct fans be speed controlled?
Yes. Certainly the single-phase motors work with phase-angle triac controllers or small variable frequency drives. However, for precise built-in control the EC versions are better, since SmartEC models take 0-10V or PWM straight from a building system.
What is the lead time for a mixed pilot run of 100 units?
Typically a batch of that size runs 15 to 25 days from order confirmation to ex-works Ningbo. Some high-volume models come from standing stock instead, which cuts it to 1 to 5 days. Mixing models does not extend the schedule.
How do I decide between the plastic and metal versions?
Work out your system static pressure first. Specifically, below roughly 150 Pa on a short duct run, the plastic series does the job for less. Above that, or where the fan runs all day, the metal AC circular duct fans are worth the difference.
Technical Documentation & Resources
Got a duty point you need matched?
Tell us the airflow, the pressure and the space you have. Then we mark your duty point on a tested curve and send the drawing back. Meanwhile samples and custom spec sheets take up to 90 days. Since 1990 we have supplied OEMs across HVAC, refrigeration and industry.
Browse Related Products:
🏆 ISO 9001 / ISO 14001 / ISO 45001 | CE (TÜV) | UL/ETL | ATEX Zone 21/22 | AMCA 210/211 / ISO 5801 tested
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