Inline Duct Fans

Inline Duct Fans — selection guide

Inline Duct Fans: 125 models, impellers Ø98–400 mm, maximum airflow 140–7,100 m³/h, static pressure to 1,030 Pa, AC, EC and DC motors, across 31 series. 49 of them carry a measured P-Q curve and 125 a dimensional drawing.

Inline duct fans install in the run of a round duct from Ø100 to Ø400 mm and are sized by duct diameter first. The range splits into four constructions: metal-cased fans (LWDD / LWDA / LWDE, up to 1,030 Pa) for long or hot runs, plastic-cased fans (LWDA, LWDE3G) for light residential systems, ultra-silent fans with an insulated casing for bedrooms and offices, and mixed flow fans whose diagonal impeller adds centrifugal pressure to axial airflow.

Motor platforms follow the same letters as the rest of the catalogue: LWDA for AC, LWDE for EC and LWDD for 12 / 24 / 48 V DC. Many models are offered as voltage pairs — 110–120 V and 220–240 V — so the same fan can be quoted for 60 Hz and 50 Hz markets.

How to select from this range

1. Match the nominal size to the duct (100, 125, 150, 160, 200, 250, 315, 355, 400 mm) and then check the duty point — the pressure of the whole run including filters, silencers and grilles.
2. Long runs, several bends or fine filters call for mixed flow or metal-cased models; short residential runs are fine with plastic-cased fans.
3. Compare sound levels at the same airflow in the data table rather than by nameplate; a larger fan at lower speed is quieter.
4. For demand-controlled ventilation choose the EC version (LWDE) with a 0–10 V controller; it runs at the airflow actually needed and cuts consumption by about 30% compared with a fixed-speed fan.
5. Check the flange type and mounting orientation on the drawing; some metal-cased models are horizontal-only.

Where these fans are used

• Residential fresh-air and heat-recovery systems
• Bathroom and kitchen exhaust
• Office and hotel ventilation
• Booster duty in long duct runs
• Grow rooms and small workshops

Every figure above is measured on our own test rigs per AMCA 210 / ISO 5801 methods — see the test labs and certificates. Final selection is confirmed at the duty point and by project validation.

FAQ — Inline Duct Fans

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