Engineering Reference Case Profile · Kitchen Appliances
Range Hoods, Ovens and Fan Coil Terminals · EC Fans Judged on Noise, Certification and the Lowest Speed
Compiled from LONGWELL’s real correspondence with kitchen-appliance groups and range-hood manufacturers in Spain, Germany, Turkey, Italy and Egypt. Appliance buyers do not select on maximum airflow. They select on how quiet the machine is at its lowest setting, whether it passes their certification regime, whether the fan physically clears the hood casing — and whether the supplier can survive their factory audit.
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
- The lowest speed is the certification point. A fan-coil manufacturer needed exactly 150 rpm at the minimum control voltage for Eurovent testing — a minimum speed that is too high pushes airflow and noise outside the certification tolerance.
- AC fans are frequency-sensitive. A range-hood fan rated at 230 V 60 Hz behaves differently on a 50 Hz market supply. Shipping the default stock variant to a 50 Hz test lab wastes the sample round.
- Chemicals compliance gates the whole programme. European kitchen brands require formal REACH declarations (with RoHS 3 and SVHC notification) before technical evaluation proceeds.
- Fit is checked in CAD before anything is built. Hood cavities are tight; 2D and 3D drawings for interference checking are part of the first response, not a follow-up.
- Appliance controls are stepped, fans are continuous. Kitchen products use 3- or 4-step push-button speed selection, so the EC fan’s continuous 0–10 V or PWM input has to be mapped onto discrete steps by the appliance main board.
- Connectors are a hard interface. On an oven programme the terminal connector had to match the customer’s new part — a detail that can block a project as effectively as a performance shortfall.
- Group buyers audit before they buy. Large appliance groups run supplier qualification through their own quality organisation; third-party factory audit reports shorten it.
2 · Solution architecture
For appliance customers LONGWELL works backwards from the certification and control regime. Minimum speed at minimum control voltage is established first, then the electrical variant is built to the destination market’s supply frequency, then 2D/3D geometry is issued for interference checking, and the compliance pack (REACH/RoHS, third-party factory audit) is prepared alongside the sample. Where the control board cannot meet a low-speed target in stock form, a two-stage response is used: firmware/voltage adjustment for the test sample, and a redesigned board for series.
Selections supplied into kitchen and appliance programmes
| Model | Ratings | Control / compliance | Application |
|---|---|---|---|
| LWBA2E-220-092NS-02 | 230 V, 112 W, 0.51 A, 2,640 rpm, 960 m³/h, 70 dBA | Built as a 50 Hz variant for the destination market; SGS factory audit report supplied | Kitchen extraction and ventilation equipment |
| LWBE3G225-072NS-07 / LWBE3G225-092NS-12 | EC backward-curved, Ø225 mm | PWM / 0–10 V; REACH, RoHS 3 and SVHC declarations on file | Premium range hood replacement selection |
| LWFE3G160-072NS-01 | EC forward-curved, Ø160 mm | PWM stepless control | Compact hood and terminal positions |
| LWFE3G-160-092NS-01 | 230 V (200–277 V), 1.28 A, 177 W, 2,160 rpm, 670 m³/h, 378 Pa, 70 dBA, IP44 | PWM stepless control | Compact hood and terminal positions |
| LWBE3G250-072 | 1,420 m³/h, 85 W, 2,800 rpm, 70 dBA | 0–10 V / PWM, mapped to 4-step selection by the appliance board; 2D drawings issued for interference check | Range hood main extraction fan |
| LWCA-60180SN-24 / -22 | Cross-flow, 180 mm impeller, 28 W and 13 W variants | Terminal connector adapted to the customer’s drawing without new tooling | Oven cooling |
| LWFC-200 / 400 / 600 / 800 series | EC forward-curved fan-coil range | 150 rpm minimum speed; 2–10 V DC control curve for Eurovent testing | Fan coil units (FCU) |
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.
Minimum speed achieved
150 rpm
Required for Eurovent certification testing of the fan coil range
Sample-stage control point
0.5 V = 150 rpm
Firmware and voltage adjustment so the lab test was not delayed
Series control point
2 V DC = 150 rpm
Achieved by redesigning the EC control board after sample approval
Frequency variant built
50 Hz to order
Rather than shipping the 230 V/60 Hz default into a 50 Hz market
Range hood duty
1,420 m³/h at 85 W
LWBE3G250-072 at 2,800 rpm, 70 dBA
Oven cooling variants
28 W and 13 W
LWCA-60180SN series on a 180 mm impeller
Compliance pack
REACH · RoHS 3 · SVHC
Issued before technical evaluation on European kitchen programmes
Audit evidence
SGS factory audit report
Used to clear a group quality organisation’s supplier qualification
4 · How these programmes run
Certification regime establishedWhich scheme applies (Eurovent, GS, CE), and what it constrains — usually minimum speed, airflow tolerance and noise.
Minimum speed and control mappingThe lowest required speed and the control voltage that must produce it are fixed, together with how the appliance board will map continuous control to push-button steps.
Electrical variant builtThe fan is built to the destination market’s supply frequency and voltage rather than shipped from default stock.
Geometry issued2D and 3D drawings go out with the first technical response so the customer’s R&D team can check interference inside the hood or oven cavity.
Compliance pack preparedREACH, RoHS 3 and SVHC declarations, plus third-party factory audit reports for group supplier qualification.
Sample and series splitWhere a low-speed target cannot be met in stock form, the sample is adjusted in firmware to keep the lab test on schedule and the control board is redesigned for series production.
5 · Engineering lessons carried forward
- Ask for the minimum control voltage and the minimum speed before anything else. On certified appliances the low end decides whether the machine passes, and a fan that will not hold 150 rpm cannot be fixed later in the duct.
- Never ship the default frequency variant to a market with a different supply. AC fan performance moves with frequency; build the 50 Hz or 60 Hz variant to order and confirm it before production is scheduled.
- Put REACH, RoHS and SVHC declarations on the table early. European kitchen brands treat these as a gate before technical evaluation, and a missing declaration stalls the project at management level rather than at engineering level.
- Send 2D and 3D geometry with the first response. Hood and oven cavities are tight, and the customer’s R&D team cannot start without a model to check interference against.
- Explain how a continuous EC input becomes stepped control. Appliance products use 3- or 4-step buttons; showing how the main board maps that onto 0–10 V or PWM removes a common objection.
- Have the connector reviewed by an engineer early. Offering a terminal adaptation without new tooling is often what lowers the customer’s evaluation threshold on an oven or hood programme.
- Where a low-speed target needs hardware change, split the response: adjust firmware for the certification sample so the lab date holds, then redesign the board for series. It buys development time without losing the project.
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, brand artwork, 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 and rounded to a band, in the currency as invoiced; many threads on this page are sampling or qualification stages, where the recorded value is a sample order rather than the series volume. Unit prices are never published.
Fan coil range — 150 rpm for Eurovent certification
- Requirement: every model in the LWFC-200 to LWFC-800 range had to deliver exactly 150 rpm at the minimum control voltage, with a matched speed curve from 2 V to 10 V DC. Too high a minimum speed would push airflow and noise outside the Eurovent tolerance.
- Two-stage response: for the certification samples, firmware and circuit parameters were adjusted so that 0.5 V produced 150 rpm, keeping the customer’s laboratory schedule intact.
- For series production the EC control board was redesigned and re-verified so that the standard 2 V DC control point produces 150 rpm on a linear speed curve.
Premium range hood — European fan replacement with REACH pack
- Replacement selections for two incumbent European fans: LWBE3G225-072NS-07 and LWBE3G225-092NS-12 EC backward-curved for the larger duty, and LWFE3G160-072NS-01 EC forward-curved for the smaller.
- LWFE3G-160-092NS-01 published duty: 230 V (200–277 V), 1.28 A, 177 W, 2,160 rpm, 670 m³/h, 378 Pa, 70 dBA, IP44.
- Formal REACH declarations including RoHS 3 and SVHC notification were issued by the compliance team before technical evaluation continued. Where a published curve had been revised, the correction was disclosed to the customer rather than left in place, with PWM stepless control used to match the working point in the customer’s own duct.
Kitchen appliance group — 50 Hz variant and factory audit
- LWBA2E-220-092NS-02 at 230 V, 112 W, 0.51 A, 2,640 rpm, 960 m³/h, 70 dBA.
- The default specification is 60 Hz, but the end market runs at 50 Hz. Engineering raised this before the sample was scheduled and built a 50 Hz variant with re-confirmed speed and power, so the customer’s laboratory measured the right thing.
- A third-party SGS factory audit report was supplied to clear the group quality organisation’s supplier qualification.
Range hood fan — CAD interference check and 4-step control
- Duty: 1,420 m³/h, 85 W, 2,800 rpm, 70 dBA, with 0–10 V speed control, fitting inside the hood casing.
- LWBE3G250-072 EC backward-curved was proposed with 2D drawings so the customer’s R&D team could check interference in the hood cavity before committing.
- The customer asked whether 4-step speed selection was possible; the answer was to keep the fan on continuous 0–10 V/PWM and let the appliance main board map it onto four preset steps.
Oven cooling — connector adapted without new tooling
- Oven cooling cross-flow fans on a 180 mm impeller: LWCA-60180SN-24 for the 28 W duty and LWCA-60180SN-22 for 13 W, with dimensions and power matched to the customer’s existing structure.
- The controlling constraint was the terminal connector, which had to match the customer’s new part. Engineering reviewed their drawing and confirmed the terminal could be adapted without new tooling, then issued complete drawings for sample testing.
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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