🔥 Get Full Catalog
Engineering Reference Case Profile · Tier 3 Colocation Retrofit

50-Fan CRAH FanGrid Retrofit · 2 MW Tier 3 Colocation

A composite reference case based on representative CRAH FanGrid retrofit projects in the colocation segment — replacing legacy belt-drive AC fans with EC plug-fan arrays for N+1 redundancy, lower PUE, and 4-week procurement vs 14–22 week European-premium lead time.

Project size: 50-fan CRAH FanGrid · 2 MW IT load · Tier 3 colocation Reference period: Composite reference · representative of 2024–2026 deployments Geography: EU + North America retrofit segment
About this case profile: This is an anonymized composite reference case based on representative LONGWELL platform deployments in the AI Data Center / Colocation segment. It illustrates the engineering challenge, solution architecture, and measurable outcomes typical of projects in this class. Performance numbers reflect LONGWELL platform validated specs plus industry-standard improvement deltas, not a specific named customer claim. Real customer references are available under NDA on project qualification (sales@longwellfans.com).

1 · Challenge

  • Legacy belt-drive AC fans operating at 1.45 PUE — typical for pre-2018 CRAH installations.
  • Original spec called for ebm-papst K3G500 RadiCal × 50, but 2026 lead time of 14–22 weeks blocked the colocation site's customer-commit move-in date.
  • Site required N+1 redundancy (single-fan failure must not interrupt cooling), per-fan runtime telemetry to DCIM, and 24/7 operating envelope.
  • Acoustic constraint <55 dB(A) at staff-walk-aisle adjacency.

2 · Solution Architecture

5 × 10 fan grid replacing 5 belt-drive AC fans on N+1 control. Each row of 10 fans operates 9 active + 1 hot standby. Master/slave Modbus topology auto-redistributes load on fault. LONGWELLBUS gateway publishes runtime + RPM + thermal + fault data to existing Vertiv Trellis DCIM.

Bill of materials

LONGWELL SKUTypeQtyKey spec
LWBE3G-500-ECEC backward-curved plug fan50 unitsØ500 mm, 89% η, 38 dB(A) floor, IP54, 0–10 V + Modbus RTU master/slave
LONGWELLBUS gatewayFree cloud telemetry5 zones × 10 fansPer-fan runtime, RPM, fault to DCIM via Modbus TCP

3 · Measured Outcomes

PUE delta
1.45 → 1.32
−0.13
Fan energy reduction
28%
vs prior AC + belt
Lead time PO → install
5 weeks
vs 14–22 wk ebm-papst
CapEx delta vs spec
−52%
vs original K3G500 BOM
Field failure rate
0.3%
12 months in service
Payback period
18 months
energy + downtime risk

4 · Implementation Timeline

Week 0PO placed for 50 × LWBE3G-500-EC + 5 LONGWELLBUS gateways
Week 1–4Series production at Yuyao + Hai Phong factories
Week 4Sea freight + EU bonded warehouse customs clearance (Rotterdam)
Week 5Site delivery + Saturday/Sunday CRAH-by-CRAH installation (no downtime)
Week 6Commissioning + Modbus integration into Vertiv Trellis
Week 7+Live operation, runtime telemetry feeding DCIM

5 · Engineering Lessons

  1. Lead time was the binding constraint, not peak η. The 2 pp η delta vs ebm-papst (89% vs 91%) was not visible in the annual energy bill because CRAH duty operates at 50–70% load most hours, where both fans hold flat η.
  2. Modbus master/slave parallel control with auto load redistribution on fault was the simplest path to JCI N+1 compliance without separate redundant fan banks.
  3. LONGWELLBUS gateway integration to Vertiv Trellis took 2 working days because the Modbus register map was published in advance — no custom BMS programming.
  4. Acoustic at 4 m staff aisle measured 47 dB(A) at 60% load (well under 55 dB(A) limit). Datasheet 38 dB(A) floor at 1 m proved out at install distance.
  5. Saturday/Sunday install cadence avoided customer downtime. Drop-in dimensional match to legacy mount allowed 4 CRAH per shift install rate.

Related Resources

📊 Industry Ranking 2026Best EC Fans · this segment · top 10 benchmarked 📦 Industry Pack (EN)Full solution Pack with products + NPI + certifications 📋 Cross-Reference (130+ SKU)Full ebm-papst / Z-A / Nicotra / Rosenberg → LONGWELL 📚 All 10 Case ProfilesBrowse industry reference projects

Get a sized BOM for your project

Send your application duty point (CFM, Pa, ambient T, IP, certification scope). LONGWELL Engineering returns a sized BOM, AMCA test data, and reference deployment schedule within 24 hours.

📧 Request Sized BOM Browse All 10 Case Profiles

Official LONGWELL Product Categories

Browse the live product range and request quotes directly on longwellfans.com

Backward-Curved Centrifugal EC FansLWBE3G plug fans EC Axial FansLWAE3G axial Forward-Curved Centrifugal FansLWFC blowers EC Inline Duct FansLWM mixed-flow Commercial Centrifugal BlowersAT / DD / RDH / ADH series FFU Fans & MotorsCleanroom FFU Transformer Cooling Cross-Flow FansDry-type transformer Air-Source Heat Pump SystemsHeat pump