Engineering Reference Case Profile · Air Curtain OEM
Air Curtain OEM Programme · Cross-Flow Barrels, Impellers and the EC Axial Upgrade Path
Compiled from LONGWELL’s real correspondence with air-curtain manufacturers in Turkey, Russia, Ukraine and the UAE. Air-curtain builders buy in two directions at once: long, quiet cross-flow barrels for the standard product line, and higher-airflow EC axial or centrifugal fans as their premium models move to variable speed — usually on the same delivery.
About this case profile: This profile is compiled from real LONGWELL project correspondence in this segment. Customer names, commercial terms and pricing are withheld; company names and branding have been removed from the photographs. Model numbers, electrical ratings and dimensions are quoted from LONGWELL controlled datasheets, product nameplates and customer-approved drawings. Where a figure is a typical range rather than a measured project result it is labelled as such. Named references are available under NDA on project qualification (sales@longwellfans.com).
1 · Challenge
- Air curtains need an even discharge across the full door width. That means long cross-flow barrels — 647 mm and 871 mm in one Turkish programme — in both left- and right-hand rotation, matched in pairs on wide doors.
- Impeller material is a live decision: ABS versus aluminium changes stiffness, temperature tolerance, noise and cost, and drives a different bearing and hub specification.
- As premium models move to variable speed, the same customer needs an EC axial or EC centrifugal option with 0–10 V or PWM control, protection functions, and a defined sample programme — without holding the bulk barrel shipment.
- Control interface is not a free choice. On the current controller, 0–10 V / PWM and Modbus RS-485 are mutually exclusive; the customer has to decide before the board is built, not after.
- Nameplate and document accuracy matters more than it looks: one batch shipped with a transposed model suffix on the label, and the correction had to be made after the goods were already palletised and crated.
- Long cross-flow barrels are light and tall on a pallet. They are easily crushed in transit, and surface protection has to survive humid sea freight and long storage before installation.
2 · Solution architecture
For this segment LONGWELL supplies at three levels: bare impellers and barrels to builders who wind and assemble their own motors; complete cross-flow fan assemblies with motor, bracket and grill; and EC axial / centrifugal fans for the higher-airflow premium models. Sampling for a new EC model runs in parallel with bulk barrel production, and the two are either consolidated or split according to the customer’s line schedule.
Typical selections in this segment
| Model / item | Key ratings | Control & protection | Role in the machine |
|---|---|---|---|
| Aluminium cross-flow barrel 150 × 647 mm | Ø150 mm, LH and RH rotation | — | Standard-width air curtain discharge |
| Aluminium cross-flow barrel 150 × 871 mm | Ø150 mm, LH and RH rotation | — | Wide-door air curtain discharge |
| ABS / aluminium cross-flow impellers | Multiple diameters and lengths | — | Material choice by noise, stiffness and temperature |
| LWAE3G450SS-5MEW-09 (EC axial) | 230 VAC (176–264 V), 50/60 Hz, 1,670 rpm, 264 W, 1.16 A | 0–10 V / PWM; over-temperature, over-current, locked-rotor and under-voltage protection | High-airflow premium air-curtain models |
| LWBA2E280-092NS-03F (AC centrifugal) | 230 VAC (200–240 V), 50 Hz, 2,570 rpm ±5%, 203 W ±10%, 0.88 A ±10%, 1,800 m³/h max | Fixed speed | Ducted and cabinet air-curtain variants |
| LWBE3G series (EC centrifugal) | Backward-curved EC plug fans | 0–10 V / PWM or Modbus RS-485 — not both on one controller | Variable-speed premium models |
| LWCD 12 / 24 V DC cross-flow | Single, double and triple impeller sections on one shaft | 0–10 V | Low-voltage and vehicle-mounted air curtains |
3 · Verified figures
Fan performance figures are quoted from LONGWELL controlled datasheets and product nameplates and are tested per AMCA 210/211 methods; third-party reports available on request. EC versus AC energy saving is approximately 30%, higher under strongly varying load — confirm against your own load profile. Final selection must be confirmed against the actual duty point (airflow, static pressure, ambient temperature, certification scope) of your machine.
Barrel sizes in production
150 × 647 / 150 × 871 mm
Aluminium, supplied in both left- and right-hand rotation
EC axial upgrade
1,670 rpm · 264 W · 1.16 A
LWAE3G450SS-5MEW-09 at 230 VAC, range 176–264 V
AC centrifugal option
2,570 rpm · 203 W
LWBA2E280-092NS-03F, 1,800 m³/h max airflow, 0.88 A
Control interface rule
0–10 V / PWM or RS-485
Mutually exclusive on the current controller — decided before board build
EC sample lead time
15 days
Typical for a new EC axial model; runs in parallel with bulk barrel production
Certification on despatch
CE + EAC
Marked on the carton and shipping label for the EAEU route
4 · How these programmes run
EnquiryDoor width and discharge requirement fix barrel diameter, length and rotation. Left/right pairing is confirmed at this point, not at packing.
Material decisionABS or aluminium is settled against noise, stiffness, operating temperature and the customer’s own assembly method, together with the matching bearing and hub.
Sample roundBarrels and, where a new EC model is involved, a sample fan are built. Sample lead time for a new EC axial is typically 15 days.
Control alignmentBefore the EC board is built the customer confirms 0–10 V / PWM or Modbus RS-485, and the lead definitions are marked on the drawing.
Bulk production & labellingNameplates are proofed against the datasheet before palletising — the one time this was missed, the label correction had to be handled after crating.
Consolidation or split despatchSample and bulk are either consolidated or shipped separately depending on the customer’s line schedule; pros and cons are put in writing before booking.
5 · Engineering lessons carried forward
- Settle the control protocol before the board is built. 0–10 V / PWM and Modbus RS-485 cannot coexist on the current controller — confirming this at the technical alignment stage, and marking lead definitions on the drawing, avoids a rework cycle after the order is placed.
- Proof the nameplate before packing. A transposed suffix on a label turned into datasheet reissues, an invoice amendment and photographic evidence for customs — all after the goods were crated. A pre-packing nameplate check is far cheaper.
- When sample and bulk lead times conflict, put the trade-off to the customer in writing. Split despatch costs more freight; a combined shipment risks their production date. That is their call, and it needs to be made before booking.
- Air-curtain customers are a natural upsell path. A builder buying barrels in volume is usually also specifying an axial or centrifugal fan for their premium line — the EC range should be introduced during the bulk delivery, not at the next enquiry.
- Long cross-flow barrels are light but easily crushed. Palletising and stacking guidance goes out in writing with the shipment; surface protection is specified for humid sea freight and extended storage before installation.
6 · Project evidence
Every item below is a real project thread from LONGWELL’s own correspondence. Each carries an anonymised case reference, the counterparty described by industry and buying role only, an evidence grade, the actual dates from first contact to close, the length of the email thread and, where an invoice is on file, the order value band. Customer names, domains, prices and commercial terms are withheld — including from the photographs. Evidence grade A means controlled documents or test reports are on file for that thread; grade B means a structured enquiry and specification are on file. Order value bands are read from the proforma or commercial invoice held on file for that thread and are rounded to a band; the invoice currency is shown as invoiced. A band is only given where the invoice currency is unambiguous — 20 of the threads on these pages carry one. Unit prices are never published.
Bulk aluminium barrels plus a new EC axial sample, on one programme
- Delivered 150 × 647 mm and 150 × 871 mm aluminium cross-flow barrels in both rotations for the customer’s standard air-curtain line, with telex-released documents.
- In parallel, sampled LWAE3G450SS-5MEW-09 EC axial (230 VAC, 176–264 V, 50/60 Hz, 1,670 rpm, 264 W, 1.16 A) with 0–10 V / PWM speed control and over-temperature, over-current, locked-rotor and under-voltage protection, for their next-generation unit.
- The 15-day sample lead time conflicted with the bulk despatch date; the split-versus-combined trade-off was put to the customer in writing before booking.
Nameplate correction and an EC control-protocol decision
- LWBA2E280-092NS-03F AC centrifugal: 230 VAC (200–240 V), 50 Hz, 2,570 rpm ±5%, 0.88 A ±10%, 203 W ±10%, 1,800 m³/h maximum airflow.
- A batch shipped with a transposed model suffix on the nameplate. Corrected datasheets, an amended invoice and photographs of the actual nameplate were issued; customs clearance and warehouse receipt completed without a hold. The nameplate photograph below is from that verification.
- For the follow-on LWBE3G EC selection, the customer’s engineer was told directly that 0–10 V / PWM and Modbus RS-485 cannot both be active on the current controller, and chose before the board was built.
ABS versus aluminium impellers, with matched bearing selection
- Structural comparison of ABS and aluminium cross-flow impellers across several diameters and lengths, with the corresponding bearing and hub specification for each.
- The photograph below shows the plastic cross-flow impeller range as supplied — multiple diameters, lengths and materials from the same tooling family.
Multi-size impeller customisation for terminal assembly
- Cross-flow impellers customised across several sizes so they match the customer’s existing housings and assembly fixtures, avoiding a housing redesign.
Surface protection rework and local handling
- Surface corrosion protection on cross-flow fan components was improved after field feedback, with affected units reworked locally rather than returned — the practical answer when freight time exceeds rework time.
- The warehouse photographs below are from that programme: LONGWELL cartons palletised and stretch-wrapped with CE and EAC marks, and crated long cross-flow assemblies ready for the customer’s line.
Fan performance figures are quoted from LONGWELL controlled datasheets and product nameplates and are tested per AMCA 210/211 methods; third-party reports available on request. EC versus AC energy saving is approximately 30%, higher under strongly varying load — confirm against your own load profile. Final selection must be confirmed against the actual duty point (airflow, static pressure, ambient temperature, certification scope) of your machine.
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