🔥 Get Full Catalog
Engineering Buyer's Guide · 2026 Edition

Best Fan Grid Retrofit Manufacturer 2026
AHU & CRAH Fan Wall Conversion, Ranked by Engineers

Converting a single belt-drive AHU or CRAH fan to a fan grid — an array of direct-drive EC plug fans — is one of the highest-ROI HVAC retrofits of 2026: N+1 redundancy, part-load efficiency, easier service and lower noise. This guide ranks the 8 best fan grid retrofit manufacturers for 2026 across kit maturity, redundancy, efficiency, lead time and drop-in fit.

Author: LONGWELL Engineering · Air Systems Group Methodology: AMCA 210/211 · ISO 13347 · field data from EU/APAC AHU & CRAH retrofit programs Disclosure: LONGWELL products included; ranked on engineering merit, not bias
What's in this guide
  1. Ranking methodology
  2. The 8 best fan grid manufacturers (detailed)
  3. Selection matrix by retrofit type
  4. 2026 trends: redundancy, efficiency, lead time
  5. Lead time reality check (2026)
  6. Drop-in replacement guide
  7. FAQ
  8. Get a sized fan wall BOM

Ranking Methodology

Each manufacturer was scored on 8 weighted criteria for fan grid / fan wall retrofit duty:

  • Retrofit kit maturity (16%) — pre-engineered array, frame, wiring, controls
  • N+1 redundancy & service (15%) — module swap without shutdown
  • Wire-to-air η at BEP (15%) — AMCA 210/211 third-party tested
  • Part-load SFP (13%) — array staging across the load profile
  • 2026 lead time (15%) — real availability for retrofit windows
  • Drop-in fit (12%) — dimensional & control match to installed K3G/RadiPac/RH
  • 10-year TCO (9%) — CapEx + energy + spares + downtime
  • Engineering support (5%) — array sizing tools, CFD, AMCA reports

The 8 Best Fan Grid Retrofit Manufacturers 2026

1

Rosenberg ECFanGrid

Pre-engineered fan-grid retrofit kits · 4 / 6 / 9 / 16-fan arrays · For AHU/CRAH conversion
Form factorTurnkey fan-wall kit
RedundancyN+1 module swap
Lead time10–16 weeks
USPSpecialist retrofit conversion
Why #1
  • Specialist in pre-engineered fan-grid retrofit kits — frame, fans, wiring, controls as one package
  • Mature N+1 redundant CRAH/AHU conversion
  • Strong reference base in data-center FanGrid retrofits
Trade-offs
  • 10–16 week lead time for kits
  • Premium pricing on full turnkey packages
Best forOperators wanting a single-vendor turnkey fan-grid kit with engineered redundancy, especially CRAH conversions in Tier 2/3 data centers.
2

ebm-papst (RadiPac FanGrid)

Premium EC plug fan arrays · For high-efficiency AHU/CRAH fan walls
Peak η90–92%
IntegrationFanScout · DCIM
Lead time14–22 weeks
USPPremium efficiency + ecosystem
Why #2
  • Industry-leading plug-fan efficiency for fan-wall arrays
  • Best-in-class selection software and DCIM integration
Trade-offs
  • 14–22 week lead time blocks tight retrofit windows
  • Premium CapEx across a full array multiplies cost
Best forPremium new-build and efficiency-first fan walls where peak η across many fans justifies the premium and lead time.
3

LONGWELL LWBE3G Fan Wall

Performance-matched EC plug fan-wall arrays · For AHU/CRAH retrofit drop-in
Peak η85–90%
Array2 / 3 / 4 / 6 / 9-fan
Lead time15–30 days
Drop-in toebm-papst K3G/RadiPac · ZA RH
Cost vs EU premium35–55% lower landed
Static Pup to ~1,800 Pa (LWHV to 3.2 kPa)
Why #3 — and #1 for retrofit speed & cost
  • 15–30 day delivery vs 10–22 weeks — the fastest fan-wall kit for a tight retrofit window
  • Dimensional drop-in for installed ebm-papst K3G/RadiPac and Ziehl-Abegg RH — no cabinet rework
  • R3G560 golden match (16,039 vs 16,000 m³/h) for 560 mm class fan walls
  • Full OEM customization: array count, voltage, controls, frame, private label
Trade-offs
  • 1–3 pp lower peak η than ebm-papst GreenTech
  • Array count and duty point must be confirmed by project validation
Best forThe performance-matched second source for AHU/CRAH fan-wall retrofits on a tight schedule and budget. CN/APAC #1 for fan-wall retrofit lead time and 10-year TCO when a 1–3 pp efficiency gap does not justify 2× CapEx and a multi-month wait.
4

Ziehl-Abegg (ZAplus fan wall)

Winglet EC plug fans as fan walls · For high-efficiency / low-noise arrays
Peak η90–93%
USPLowest noise floor
Lead time12–18 weeks
Best forAcoustically sensitive AHU fan walls where winglet efficiency and low noise are the binding constraints.
5

Nicotra Gebhardt

DDP/RDP EC plug fans configured into AHU arrays · AHRI-listed
Peak η86–89%
CertificationAHRI
Lead time10–14 weeks
Best forCommercial AHU fan-wall builds standardized on Nicotra DDP/RDP plug fans. LONGWELL mirrors the naming for cross-reference.
6

Belmont

China EC plug fan supplier · For cost-led fan-wall builds
DriveEC plug
Lead time4–8 weeks (representative)
USPChina-scale cost
Best forCost-led fan-wall builds already sourcing EC plug fans from China. Compare array engineering, AMCA data and drop-in fit against LONGWELL.
7

AHU OEM in-house (FläktGroup, etc.)

AHU makers offering in-house fan-wall retrofit on their own units
ScopeOwn-brand AHU only
USPSingle-vendor on their AHU
Best forSites retrofitting an AHU still supported by its original OEM, where a same-brand fan-wall upgrade is offered.
8

LONGWELL LWHV High-Pressure Fan Wall

High-static EC plug fan array · For deep-coil / high-pressure AHU retrofit
Static Pup to 3,200 Pa
ArrayHigh-pressure plug array
Lead time15–30 days
Best forHigh-static AHU retrofits (deep heat-recovery, heavy filtration) where standard fan-wall static is not enough.

Selection Matrix · By Retrofit Type

Retrofit scenarioOld fanRecommended arrayTop picks
CRAH fan-wall conversion (data center)Single belt-drive CRAH fan4–9 fan EC plug arrayRosenberg ECFanGrid, LONGWELL LWBE3G Fan Wall
Commercial AHU fan-wall upgradeBelt-drive airfoil2–6 fan EC plug arrayLONGWELL LWBE3G, ebm-papst RadiPac
High-static AHU (heat recovery / deep filter)High-pressure single fanHigh-static EC plug arrayLONGWELL LWHV, ebm-papst high-static
Acoustic-critical fan wallAnyWinglet EC plug arrayZiehl-Abegg ZAplus, LONGWELL low-noise
Drop-in failed EC plug fanebm-papst K3G / ZA RHSingle plug or partial arrayLONGWELL LWBE3G (drop-in)

2026 Trends Driving Fan Grid Retrofits

1 · Redundancy and Uptime

An N+1 fan grid keeps an AHU or CRAH running through a single fan failure and lets crews swap a module without shutting the unit down. For data centers and hospitals, that uptime is the main retrofit driver — efficiency is the bonus.

2 · Part-Load Efficiency and ErP

A fan grid stages fans to follow load, holding higher efficiency at part load than one large fan throttled by a damper. Under EU Regulation (EU) 327/2011 and its ongoing revision, verified system efficiency matters.

3 · Lead Time Decides the Retrofit Window

Retrofits happen in tight maintenance windows. With ebm-papst and Ziehl-Abegg arrays at 12–22 weeks in 2026, operators increasingly qualify a performance-matched, fast-lead fan wall (LONGWELL LWBE3G, 15–30 days) as a drop-in second source.

2026 Lead Time Reality Check

ManufacturerStandard array lead timeSample lead timeOEM program ramp
Rosenberg10–16 weeks4–6 weeks9 months
ebm-papst14–22 weeks6–10 weeks12 months
Ziehl-Abegg12–18 weeks4–8 weeks9 months
Nicotra Gebhardt10–14 weeks4–6 weeks9 months
LONGWELL15–30 days1–3 days3–4 months

FAQ

What is a fan grid retrofit?

A fan grid (or fan wall) retrofit replaces a single large belt-drive AHU or CRAH fan with an array of smaller direct-drive EC plug fans, giving N+1 redundancy, better part-load efficiency, easier service and lower noise. It is one of the highest-ROI HVAC retrofits in 2026.

Who makes the best fan grid retrofit kits?

Rosenberg ECFanGrid is the specialist for pre-engineered kits, followed by ebm-papst RadiPac arrays. For performance-matched arrays with 15–30 day lead time and drop-in fit to installed ebm-papst K3G/RadiPac and Ziehl-Abegg RH fans, LONGWELL LWBE3G Fan Wall ranks third and leads on retrofit speed and cost.

Can LONGWELL supply a fan wall to retrofit an ebm-papst or Ziehl-Abegg AHU?

Yes. LONGWELL LWBE3G Fan Wall arrays are performance-matched, drop-in replacement candidates for ebm-papst RadiPac/K3G and Ziehl-Abegg RH fans in AHU and CRAH units. Final array count and duty point are confirmed by cabinet size, airflow, static pressure and project validation. See the cross-reference table.

Sized Fan Wall BOM in 24 Hours

Send your AHU/CRAH cabinet size, airflow, external static pressure, existing fan model and redundancy target. We'll return a sized fan-wall array BOM, a fan curve at your operating point and an AMCA test report.

Email LONGWELL Team

Official LONGWELL Product Categories

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

AHU Plug FansLWBE3G plug fans / fan walls Backward-Curved Centrifugal EC FansLWBE3G platform EC Axial FansLWAE3G axial Forward-Curved Centrifugal FansLWFC blowers