Day: September 9, 2026

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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Fan inlet with a bend close to it causing system effect losses
By longwell / September 9, 2026 / Fan Engineering Guides

System Effect: The Hidden Efficiency Killer

A fan tested in a laboratory rarely meets its curve on site, and syste...

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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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Shaded-pole motors compared with PSC and BLDC fan motors
By longwell / September 9, 2026 / Fan Engineering Guides

BLDC vs Shaded-Pole vs PSC Motors

Three motor types cover most small fans, and they differ by a factor o...

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Motor nameplate showing insulation class and temperature rise
By longwell / September 9, 2026 / Fan Engineering Guides

Motor Insulation Class & Temperature Rise (F/H)

Insulation class sets the temperature a winding can survive. Temperatu...

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Fan motor nameplate showing IP ratings for ingress protection
By longwell / September 9, 2026 / Fan Engineering Guides

IP Ratings for Fans Explained (IP54/IP66)

IP ratings look simple until you need one. Here is what each digit act...

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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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Testing a fan run capacitor with a multimeter on the capacitance range
By longwell / September 9, 2026 / Fan Engineering Guides

How to Test & Replace a Fan Run Capacitor

A weak run capacitor causes slow starting, low speed and overheating, ...

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