Fan Engineering Guides

Video-led explanations of fan operation, selection, testing and system behavior for HVAC and equipment engineers.

Grid of small fans beside a single large centrifugal fan for comparison
By longwell / September 13, 2026 / Fan Engineering Guides

Grid of Small Fans vs One Big Fan: Efficiency Truth

Arrays are often sold as more efficient than a single large fan. On pu...

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Fan factory production line assembling centrifugal blowers
By longwell / September 13, 2026 / Fan Engineering Guides

Inside a Fan Factory: From Coil to Finished Blower

A finished blower passes through roughly a dozen processes, and each o...

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Fan test chamber set up for AMCA 210 airflow measurement
By longwell / September 13, 2026 / Fan Engineering Guides

How We Test Fans (AMCA 210/211 Method)

A fan curve only means something when you know how it was produced. Th...

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Impeller balancing machine correcting a centrifugal fan wheel
By longwell / September 13, 2026 / Fan Engineering Guides

Impeller Balancing & QC on the Line

Balancing is the last chance to catch upstream variation, and the corr...

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Backward-curved impeller being welded in a production fixture
By longwell / September 12, 2026 / Fan Engineering Guides

How a Backward-Curved Impeller Is Made

Follow a backward-curved wheel from flat steel to finished impeller. E...

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Fan P-Q curve with the duty point 8,000 m3/h at 600 Pa marked: grade C1, 22% margin, two higher grades in reserve
By longwell / September 12, 2026 / Fan Engineering Guides

Fan Curve Margin Explained: Why 10–25% Static Pressure Reserve Is the Sweet Spot

What the static-pressure margin on a fan curve measures, why 10–25% is...

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longwell fan selector home duty point
By longwell / September 12, 2026 / Fan Engineering Guides

How to Select a Fan by Duty Point: Airflow, Static Pressure and the 10–25% Margin Rule

The duty-point method for fan selection, step by step on the free LONG...

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Fan undergoing salt spray and vibration life testing in a laboratory
By longwell / September 11, 2026 / Fan Engineering Guides

Salt Spray, Vibration & Life Testing of Fans

Reliability claims mean nothing without a test behind them. This guide...

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OEM fan development prototype samples on an engineering bench
By longwell / September 11, 2026 / Fan Engineering Guides

Custom OEM Fan Development: From Spec to Sample

A custom fan project moves through five stages, and most delays happen...

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Shipping industrial fans: crated units strapped for a sea container
By longwell / September 11, 2026 / Fan Engineering Guides

Packaging & Global Shipping of Industrial Fans

Most fan damage happens in transit rather than in service, and it ofte...

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