Ziehl-Abegg RH31C Alternative — LONGWELL LWBE3G-310-EC

Looking for an alternative for Ziehl-Abegg RH31C-VDK? The LONGWELL LWBE3G-310-EC is the dimensionally interchangeable equivalent — same mounting, same control protocol, AMCA 210/211 third-party-tested performance — at 40–55% lower landed cost with 15-day delivery vs 12–18 weeks ex-works Ziehl-Abegg. Widely deployed across Commercial AHU, cold chain condensing unit, hybrid heat pump.

Replaces: Ziehl-Abegg RH31C-VDK Diameter: Ø315 mm Family: RH series → LONGWELL LWBE3G / LWAE3G / LWHV / LWFC Sample: 1–3 days
Replacing
Ziehl-Abegg
RH31C
RH series · EC backward-curved centrifugal plug fan · Ø315 mm
→
With
LONGWELL
LWBE3G-310-EC
Drop-in dimensional match · Same control · 15-day delivery

Specification Comparison

SpecificationZiehl-Abegg RH31CLONGWELL LWBE3G-310-EC
Fan typeEC backward-curved centrifugal plug fanEC backward-curved centrifugal plug fan
Impeller diameterØ315 mmØ315 mm Drop-in
Airflow range650–3,200 m³/h650–3,200 m³/h
Static pressure (max)1000 Pa1000 Pa
Motor power (max)650 W650 W
Wire-to-air η peak (AMCA 210)89%86%
Noise floor (Lw)65 dB(A)68 dB(A)
Voltage200–240 V 1Φ200–240 V 1Φ
Control input0–10 V / PWM / Modbus / EC-Control0–10 V / PWM / Modbus RTU / Modbus TCP Compatible
IP ratingIP54 / IP55IP54 std · IP55 / IP67 option
CertificationsCE · UL · VDE · EACCE · UL · cUL · TÜV · ATEX · VDE · EAC · RoHS · REACH
Sample lead time4–10 weeks1–3 days
Series lead time (≤500 units)12–18 weeks15–30 days
Landed cost index (LONGWELL = 100)175–200100 (baseline)

Why Engineers Switch from RH31C to LWBE3G-310-EC

4–8× Faster Delivery

15–30 days
vs 12–18 weeks ex-works for Ziehl-Abegg in 2026 (active allocation). Sample units 1–3 days from stock vs 4–10 weeks.

40–55% Lower Landed Cost

−€600 to −€2,400
per unit at equivalent spec, depending on size and quantity. On a 50-unit FanGrid retrofit, typical CapEx delta is €30k–€120k.

True Drop-In Compatibility

±0.5 mm
mounting hole tolerance + identical control protocol. Installation time same as same-brand replacement.

Drop-In Compatibility Details

Mechanical match

The LONGWELL LWBE3G-310-EC matches the Ziehl-Abegg RH31C mounting pattern (M-mount, ISO 9001 plenum-fan footprint) within ±0.5 mm tolerance. Inlet ring diameter, motor shaft height, and electrical termination box position are identical. Drop-in retrofit requires no AHU rework, no plate modification, and no plenum hole resizing.

Electrical & control match

The LWBE3G-310-EC accepts the same 0–10 V analog speed reference, PWM (1 kHz), and Modbus RTU (RS485) control signals as Ziehl-Abegg RH31C. Default Modbus register map is compatible with the Ziehl-Abegg ecosystem; LONGWELL provides a free Modbus map cross-reference for BMS integration. Ziehl-Abegg-specific proprietary protocols (EC-Control bus / ZA-control) are bridged via a free MODBUS gateway available from LONGWELL Engineering — no BMS reprogramming required.

Performance match

The PQ curve of LONGWELL LWBE3G-310-EC sits within 2–3% of the Ziehl-Abegg RH31C curve across the full operating envelope (verified by third-party AMCA 210/211 testing at TÜV and Intertek labs). Wire-to-air efficiency at BEP is 86% vs 89% for Ziehl-Abegg (3 pp delta at peak). In typical part-load HVAC duty, the gap narrows to within 1 pp.

Typical Applications

The LWBE3G-310-EC is widely deployed across Commercial AHU, cold chain condensing unit, hybrid heat pump. Common application categories include:

  • AHU
  • Cold chain condensing unit
  • Hybrid heat pump

Particularly suited for cold chain condensing units and hybrid heat pump split sections.

FAQ

Is LONGWELL LWBE3G-310-EC a true drop-in replacement for Ziehl-Abegg RH31C?
Yes. The LWBE3G-310-EC matches the RH31C dimensionally (mounting hole pattern, inlet ring diameter, motor shaft height) within ±0.5 mm tolerance, accepts the same 0–10 V analog / PWM / Modbus RTU control signals, and operates from the same 200–240 V 1Φ supply. Installation time and AHU integration are identical to a same-brand replacement.
How does LWBE3G-310-EC compare on efficiency to RH31C?
Ziehl-Abegg RH31C delivers 89% peak wire-to-air efficiency at BEP. LONGWELL LWBE3G-310-EC measures 86% in AMCA 210/211 third-party testing — a 3 pp difference at peak. In typical part-load HVAC duty (30–80% of design airflow), the gap narrows to within 1 pp because both platforms hold flat η curves across their operating range.
What’s the 2026 lead time difference?
As of May 2026: Ziehl-Abegg RH31C requires 12–18 weeks ex-works due to ongoing allocation. LONGWELL LWBE3G-310-EC ships in 15–30 days for orders up to 500 units and 6–10 weeks for 1,000+ unit OEM programs. Sample units ship in 1–3 days from stocked Ø315 mm inventory.
What’s the cost delta?
At equivalent specification (same Ø, same airflow/Pa, same IP, same control), LONGWELL LWBE3G-310-EC typically lands at 40–55% below Ziehl-Abegg RH31C ex-works pricing. Final pricing depends on quantity, voltage, IP rating, and control protocol options.
What applications is LWBE3G-310-EC typically used for?
LWBE3G-310-EC is widely deployed across Commercial AHU, cold chain condensing unit, hybrid heat pump. Particularly suited for cold chain condensing units and hybrid heat pump split sections.

Replace your RH31C in 5 days

Send a quick request — model + quantity + delivery address. Sample unit ships in 1–3 days for field validation. Series production at 15-day lead time after PO.

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Official Product Page
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Ziehl-Abegg® is a registered trademark of its owner. This page is published by LONGWELL, an independent manufacturer and is not affiliated with, endorsed by, or sponsored by Ziehl-Abegg. All performance data sourced from publicly available datasheets.