Fan Efficiency

Fan efficiency should be judged wire-to-air — from electrical input to useful air power — not from motor nameplate alone. Articles cover FEI metrics, part-load behaviour, annual energy calculation and the design factors separating premium EC platforms from commodity fans.

Specific speed chart mapping fan types against duty ranges
By longwell / September 9, 2026 / Fan Engineering Guides

Specific Speed: How Engineers Pick a Fan Type

Specific speed collapses airflow, pressure and rotational speed into o...

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Sound power measurement of a fan in an acoustic test chamber
By longwell / September 9, 2026 / Fan Engineering Guides

Sound Power vs Sound Pressure (dB Deep Dive)

Sound power belongs to the fan. Sound pressure belongs to the room. Co...

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Axial fan tip clearance between blade tips and the venturi ring
By longwell / September 9, 2026 / Fan Engineering Guides

Tip Clearance & Leakage in Fans

Air escaping past the blade tips is pure loss, and the gap causing it ...

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Reynolds number comparison between a small and a large fan impeller
By longwell / September 9, 2026 / Fan Engineering Guides

Reynolds Number: Scaling Fans Small to Large

Two geometrically identical fans of different sizes do not perform ide...

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Fan efficiency grade and FEI values compared on a performance curve
By longwell / September 9, 2026 / Fan Engineering Guides

Fan Efficiency Grade (FEG/FEI) Deep Dive

FEG rated the fan. FEI rates the selection. That single difference exp...

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How-to-Seal-Ducts---Cut-Leakag
By longwell / August 24, 2026 / Fan Engineering Guides

How to Seal Ducts & Cut Leakage

Duct sealing begins by identifying function, not by choosing tape or m...

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longwell-lwca-30290sn-07-proje
By longwell / August 20, 2026 / Engineering Case Studies

Repositioning the Motor on a 230V AC Cooling Unit

We turned the AC motor on a 30mm cross flow blower to clear a tight ch...

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longwell-lwa-600-project-image
By longwell / August 19, 2026 / Engineering Case Studies

Factory Cooling Requirements: 10,000 m3/h 24 Inch Industrial Drum Fan

Learn the engineering behind a 24 inch industrial drum fan. See how pu...

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By longwell / August 17, 2026 / Engineering Case Studies

24V PWM Blower: 365 m3/h Cooling in a 760x80mm Profile

Learn how we engineered a 24V DC cross flow fan with custom PWM speed ...

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IE1 vs IE2 vs IE3 vs IE4 vs IE5
By longwell / August 14, 2026 / Technical Articles

IE Motor Efficiency: IE1 vs IE2 vs IE3 vs IE4 vs IE5 Compared

One of the most important measurement for electric motor is its effici...

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