Two duty tiers and a deliberate first batch
An industrial OEM developing a heat exchange system ordered two AC axial fan variants, and structured the purchase around a pilot production run: exactly 50 units for field validation before any volume commitment.
The two tiers split by duty: 7468 m3/h for the primary condensers, and 6515 m3/h for a secondary loop.
The fixed conditions
- First, a cylindrical space exactly 565mm across and no deeper than 192mm.
- Next, 220 VAC single-phase at 50 Hz, outdoors from -30C to +60C.
- Meanwhile 70 dB(A) maximum on the high-power unit.
- Finally, CE with EN 60335-1, ISO 5801 testing, and 30,000 hours L10 at 40C, maintenance-free.
Why fifty, and why now
Samples prove a design. However, they do not prove a production process, a supply chain, or a fan bolted into real gear in real weather.
Fifty units is large enough to work all three, yet small enough to change course cheaply. That is the whole art of sizing a pilot production run.
What a pilot production run proves
Here the design decisions were settled before the pilot, which is the correct order. A pilot production run validates decisions; it does not make them.
The decisions the pilot inherits
First, we weighed EC motors and set them aside. The customer control board is hardwired for direct 220 VAC mains, and a redesign would break their 90-day schedule for a gain this fixed-duty system cannot use.
Likewise, the impeller went to cold-rolled steel over glass-fiber plastic, since -30C plus nonstop 1380 RPM is exactly the mix where polymers turn brittle. Both were sample-stage calls, made and closed.
What the fifty units actually test
Process, first. One sample gets built by careful hands, while fifty units flow through tooling, fixtures and second shifts. Consequently the pilot shows the variation: balance scatter, seam drift, torque spread on fasteners.
Fleet behavior, second. Fifty fans in real heat exchangers meet real rain, real grid sag and real installer habits. So a single field season with fifty units surfaces the failure modes no test chamber schedule predicts.
What must be recorded, or the pilot is wasted
Every pilot unit needs an identity: a serial number, a build date, measured balance and resistance at dispatch. Otherwise, field returns without baseline data are anecdotes.
With baselines, the same returns become engineering: this unit shifted this much in this condition. In fact, that difference is the entire yield of the batch.
The gate on the other side
The volume order releases only against the pilot findings, with the pass criteria agreed before the batch ships rather than haggled after.
Meanwhile, aerodynamic verification for both tiers follows ISO 5801 methods, and the pilot units carry the same test basis the volume units will.
Technical Specifications
Every figure below was met by the samples. The pilot batch exists to prove the fiftieth unit meets them too.
| Parameter | LWAA4E500S-5MYB-19-00 | LWAA4E500S-5MYB-16-00 |
|---|---|---|
| Nominal Voltage | 220 VAC (198~242 VAC) | 220 VAC (198~242 VAC) |
| Frequency | 50 Hz | 50 Hz |
| Speed | 1380 RPM | 1380 RPM |
| Current | 2.1 A | 1.6 A |
| Power input | 450 W | 370 W |
| Air flow (Max) | 7468 m³/h (4393 CFM) | 6515 m³/h (3832 CFM) |
| Capacitor | 15 μF | 8 μF |
| Noise level (LpA) | 70 dB(A) | 69 dB(A) |
| Operating Temperature | -30°C to +60°C | -30°C to +60°C |
| Insulation Class | Class F | Class F |
| Protection Type | IP54 | IP54 |
| Life Expectance | 30,000 Hours (L10) | 30,000 Hours (L10) |
| Certifications | CE, RoHS, REACH | CE, RoHS, REACH |
Technical Documentation
The visual illustrates the specific housing and mounting flange structure required for the 565mm installation space.
Download Technical Specification Sheet
Procurement managers can review the complete electrical characteristics and P-Q performance curves for both the 450W and 370W models in this document.
Download Engineering Drawings and Standards
Mechanical engineers will need this file to verify the 192mm depth constraints and confirm CE compliance standards.
Open project requirement summary 1
Here the document contains the original project request outlining the initial 50-unit pilot run and model targets.
View project requirement summary 2
The technical team uses this file to cross-reference the client’s requested part numbers against the final Longwell BOM.
Running a pilot batch properly
A pilot production run repays exactly the discipline you invest in it. Four practices carry most of the value.
- Freeze the design before the pilot, and hold the freeze. A pilot production run that absorbs design changes mid-batch validates nothing, because no two units share a configuration. Changes wait for the gate unless they are safety-critical.
- Agree the pass criteria before the batch ships. Define what field validation must show: failure count, performance drift, installer feedback. Criteria set afterwards bend toward whatever happened.
- Serialize and baseline every unit. Measured data at dispatch turns every field return into a comparison instead of a mystery. The cost is minutes per unit; the alternative is arguing about what the fan was like when it left.
- Spread the fifty across real conditions. Fifty units at one friendly site is one data point wearing fifty costumes. Coastal, inland, hot roof, cold yard: the spread is what makes the number mean something.
See our axial fans range, the industrial axial fans section, or AC axial fans.
Questions about pilot batches
How big should a pilot batch be?
Big enough to work the production process and cover several sites, yet small enough that a redesign does not strand serious money. Fifty sits in the sweet spot for equipment of this class; complex or costly assemblies often pilot smaller.
What is the difference between samples and a pilot run?
Samples prove the design, and they often get built with outsized care. A pilot production run proves the process: ordinary tooling, ordinary operators, ordinary pace. That distinction is exactly why passing samples does not guarantee a clean pilot.
How long should field validation last?
Long enough to cross the conditions the datasheet claims. For outdoor fans rated -30C to +60C, that really means spanning a season change. After all, a window that never sees the cold end validates half the datasheet.
What happens if the pilot finds a problem?
That is the pilot succeeding, not failing. A fault found across fifty units costs a fix and a delay. The same fault across five thousand costs a recall. So the gate exists precisely to surface problems on the cheap side of it.
Technical Documentation & Resources
Need the same thing for your own unit?
Give us the numbers and the envelope, and you get a shortlist rather than a catalog. Meanwhile custom spec sheets and samples run to 90 days. Since 1990 Longwell has supplied EC fans and blowers to OEMs in HVAC, cold chain, data center and industrial markets.
Browse Related Products:
🏆 ISO 9001 / ISO 14001 / ISO 45001 | CE (TÜV) | UL/ETL | ATEX Zone 21/22 | AMCA 210/211 / ISO 5801 tested
Choose the right axial fan
Longwell manufactures 1,067 axial fans in-house. Send airflow, static pressure and voltage — an engineer replies with a matching model, performance curve and price within one working day.
