Training large language models (LLMs) requires large GPUs operating for months. With such AI workloads continues to increase, data center cooling system are facing the new challenge. The next-generation data center cooling will be the combination of both liquid cooling and air cooling. Compared to traditional CRAH fan configurations, LONGWELL EC fanwall technology provide the flexibility and part-load efficiency required by data center cooling in the AI era.
LONGWELL LWBE3G EC Plug-fan Platform
LONGWELL’s LWBE3G EC plug-fan platform enables FanWall arrays that cut CRAH fan energy by 38%, reduce noise by 6.5 dB(A), and improve CRAH system PUE contribution from 1.42 to 1.28. The platform covers the full data center airflow chain: LWBE3G for CRAH/CRAC, LWAE3G for condensers and cooling towers.
As AI training racks push heat density from 15-20 kW to 60-100 kW per rack, EC FanWall technology has become the default air-moving solution for new Tier-3 and Tier-4 data centers targeting PUE ≤ 1.3.
How the 38% Energy Reduction Works
The 38% fan energy reduction comes from three compounding improvements over the previous AC motor plus scroll fan configuration: EC motor efficiency, variable-speed control, and FanWall array aerodynamics.
| Improvement Source | Mechanism | Energy Impact |
| EC Motor | Brushless DC motor with integrated drive electronics; efficiency up to 90% vs. 60-70% for AC induction motors at partial load | ~18-22% |
| Variable Speed | 0-10V, PWM, or Modbus signal modulates fan speed to match real-time cooling demand | ~8-12% |
| FanWall Aerodynamics | Backward-curved impeller design with CFD-optimized inlet ring; multiple smaller fans run closer to peak efficiency than one large scroll fan | ~6-8% |
The LWBE3G plug fan uses a backward-curved centrifugal impeller driven by an EC external-rotor motor. The motor and wheel sit in one sealed package, eliminating the shaft seal, coupling, and belt drive losses typical of traditional AC fan assemblies. At the validated duty point (200-300 Pa static pressure, 4,500-16,000 m³/h per fan), the LWBE3G achieves static pressure efficiency of 73-82%.
Case Study: Top-3 Global Precision Cooling OEM
In Q4 2024, a top-3 global precision cooling OEM approached LONGWELL for a new CRAH platform targeting PUE ≤ 1.3. The customer needed to ship product by Q2 2025 to capture the AI training rack cooling market. LONGWELL delivered from spec lock to mass production in 90 days.
90-Day NPI Timeline
| Date | Milestone | Key Actions |
| Day 1 – 14 | Spec Lock + Certification Matrix + Timing | LONGWELL provides operating points, specification, production window, and conference calls |
| Day 15 – 45 | CFD Complete | Full-machine CFD + performance prediction report + technical review |
| Day 46 – 70 | Samples Delivered | 12 engineering samples; customer factory DV started |
| Day 71 – 90 | DV/PV Passed | DV/PV verification; customer technical release signed, mass production |
Validated Outcomes
| Metric | Requirement | Actual |
| CRAH PUE contribution | ≤ 1.30 | 1.28 |
| Fan energy reduction (vs AC + scroll) | ≥ 30% | 38% |
| Noise reduction | ≥ 4 dB(A) | 6.5 dB(A) |
| DV/PV first-time pass rate | ≥ 95% | 100% |
| MTBF (measured Q2 2025 – Q1 2026) | ≥ 50,000h @ 40°C | Zero field failures |
| 2025 full-year deliveries | — | 80,000+ units |
| Framework agreement | — | 2025-2027, 60,000/year min. |
The Four-Layer Data Center Cooling Architecture
LONGWELL covers the full data center airflow chain with two EC fan platforms. The LWBE3G serves Layer 2 (CRAH/CRAC internal fans), and the LWAE3G serves Layers 3 and 4 (outdoor condensers and cooling towers). Together, L2 through L4 account for over 95% of OEM fan procurement scope for data center cooling.
| Layer | Subsystem | LONGWELL Product | Key Specs |
| L1 | Rack-level (server internal + cabinet rear door) | 40-200mm DC axial (separate line) | 12V / 48V DC |
| L2 | CRAH / CRAC precision cooling | LWBE3G Plug Fan + FanWall array | 200-300 Pa · EC + Modbus · N+1 |
| L3 | Outdoor condenser | LWAE3G EC axial (500-710mm) | IP55 std · EMC Class B · -40°C to +60°C |
| L4 | Cooling tower / dry cooler | LWAE3G EC axial (710-1000mm Cube) | 4-16 fan array · 100% humidity rated |
FanWall Technology: N+1 Redundancy
A FanWall array is a matrix of independent EC plug fans installed inside a single CRAH or CRAC cabinet. Instead of one large belt-driven fan, the system uses 4 to 9 smaller direct-drive fans, each with its own motor, controller, and communication channel.
- N+1 redundancy: It means the array is designed with one extra fan beyond what the cooling load requires. If any single fan fails, the remaining fans automatically increase speed to compensate, maintaining total airflow without interruption.
- High Energy Efficiency: EC FanWall systems can adjust the speed instead of continuously operating at full capacity. This can efficiently reduce the fan speed during part-load conditions to reduce energy consumption.
- Lower Maintenance Requirements: EC FanWall generally use direct-driven fan types, so it has no components like belts and pulleys like traditional belt-driven systems. Each fan in FanWall can be serviced independently, which can simplify the maintenance in large AHU projects.
- Improved Airflow Distribution: Multiple fans distributed across the fan section can provide a more uniform airflow pattern than a single large blower if the system is properly designed.
LWBE3G Selection Guide: Matching FanWall Arrays to CRAH Capacity
The LWBE3G platform is available in various impeller sizes and scales from 2×2 to 3×3 FanWall arrays. The following table maps CRAH capacity to the recommended configuration.
| CRAH Capacity | Model | Array Config | Total Airflow | Total Power |
| 30 kW (Tier II) | LWBE3G-400 | 2×2 (4 fans) | 18,000-39,000 m³/h | 3.4-6.6 kW |
| 60 kW (Tier III mid) | LWBE3G-450 | 2×3 N+1 (6 fans) | 34,800-75,000 m³/h | 6.6-13.2 kW |
| 100 kW (Tier III large) | LWBE3G-500 | 2×4 N+1 (8 fans) | 60,000-128,000 m³/h | 12.0-24.0 kW |
| 150 kW (Tier IV critical) | LWBE3G-500 | 3×3 N+1 (9 fans) | 67,500-144,000 m³/h | 13.5-27.0 kW |
Industry Context: Why 60 kW Per Rack Changes Everything
AI compute has redefined data center cooling. In 2020, typical rack heat density was 5-15 kW per rack. By 2024-2026, AI training racks pushed heat density to 60-100 kW per rack. Next-generation Blackwell B200 platforms are expected to exceed 100-200 kW per rack.
At 60+ kW per rack, AC fans with belt-driven scroll configurations cannot maintain PUE ≤ 1.3. The fan stage becomes the limiting factor in whether a PUE target is reachable at all. Since 2024, new Tier-3 and Tier-4 data centers have adopted EC fans at effectively 100% penetration rate.
Global PUE regulations are tightening simultaneously. Hyperscale operators aim for ≤ 1.15. EC fans contribute an average PUE improvement of 0.10-0.18 compared to AC equivalents.
LONGWELL vs. Incumbent European Brands: Cross-Reference
LONGWELL EC fans are designed as drop-in alternatives to incumbent European brands. The following table maps equivalent product lines. Full cross-reference guide available at Cross Reference Guide.
| Application | LONGWELL | ebm-papst | Ziehl-Abegg |
| CRAH Plug Fan (FanWall) | LWBE3G-400/450/500 | K3G Series | RH Series |
| Condenser Axial | LWAE3G-500/560/630/710 | W3G Series | ZAbluefin Series |
| Cooling Tower Axial | LWAE3G-800/910/1000 | W3G Series | ZAvblue and FN Series |
Certification and Compliance Matrix
The LONGWELL EC fan platform carries the certifications required for global data center deployment, including the strictest IT-grade EMC standards.
| Certification | Standard | Scope |
| EMC Class B | EN 55014-1/2 Class B | Full EC platform · strictest IT-level EMC |
| FCC | FCC Part 15 Class B | Full EC platform · US IT EMC |
| UL | UL 507 (fans) + UL 1004-1 (motors) | LWBE3G 6 NA sizes + LWAE3G 4 NA sizes |
| ErP Tier 2 | EU EED Directive | Full EC platform |
| AMCA 210 | AMCA 210-16 | Performance verification equivalent to T3 evidence |
| CE / CCC / RoHS / REACH | — | Full series |
| ISO 9001 / 14001 / 45001 | — | Manufacturing facility certified |
Frequently Asked Questions
What is EC FanWall technology in data center cooling?
EC FanWall technology uses an array of EC (electronically commutated) plug fans—typically backward curved centrifugal blowers with integrated brushless DC motors—arranged in a 2×2 to 3×3 matrix inside a CRAH or CRAC unit.
How much energy does the LONGWELL EC FanWall save compared to AC fans?
In a validated deployment with a top-3 global precision cooling OEM, LONGWELL’s LWBE3G FanWall arrays reduced CRAH fan energy by 38% compared to the previous AC motor plus scroll fan configuration.
What is the LONGWELL 90-day NPI process for data center fans?
LONGWELL’s 90-day New Product Introduction (NPI) process has four stages: S1 (Day 1-14) spec lock including duty point, Tier rating, and production window; S2 (Day 15-45) design with CFD simulation, FanWall layout, and communication mapping; S3 (Day 46-70) sample delivery of 3-12 engineering units with on-site DV support; S4 (Day 71-90) DV/PV completion, mass production archiving, and first batch delivery of 100-1,500 units.
What certifications do LONGWELL data center EC fans carry?
LONGWELL’s EC fan platform carries EMC Class B (EN 55014-1/2), FCC Part 15 Class B, UL 507 (fans) and UL 1004-1 (motors), CE, CCC, RoHS, REACH, ErP Tier 2 compliance, and AMCA 210-16 performance verification. The manufacturing facility holds ISO 9001, ISO 14001, and ISO 45001 certifications.
About LONGWELL
Founded in 1990 in Yuyao, Ningbo, China, LONGWELL (Ningbo Longwell Electric Technology Co., Ltd.) designs and manufactures EC, DC, and AC fans and motors for HVACR and industrial applications. The 40,000+ m² facility exports to more than 30 countries with annual data center fan capacity exceeding 120,000 units. LONGWELL serves Fortune 500 companies and top-tier OEM brands with products spanning centrifugal, axial, cross-flow, plug, and duct fans, all backed by ISO 9001/14001/45001 certified manufacturing.
The full 28-page Data Center Cooling Solution Pack is available at LONGWELL official website.
