Fan Engineering Guides

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

How a Squirrel Cage Blower Works
By longwell / September 20, 2026 / Fan Engineering Guides

How a Squirrel Cage Blower Works

A squirrel-cage blower does not move air straight through the wheel. T...

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Total vs Static vs Velocity Pressure (Fan Curves 101)
By longwell / September 20, 2026 / Fan Engineering Guides

Total vs Static vs Velocity Pressure (Fan Curves 101)

Why can two fan curves show the same airflow but different pressure? T...

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What Is Fan Efficiency (FEI) and Why It Matters
By longwell / September 20, 2026 / Fan Engineering Guides

What Is Fan Efficiency (FEI) and Why It Matters

An FEI of 1.25 does not mean 125% efficiency. This engineering walkthr...

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Blower vs Fan — What's the Difference?
By longwell / September 20, 2026 / Fan Engineering Guides

Blower vs Fan — What’s the Difference?

Fan, blower, and compressor are not separated by one universal pressur...

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EC vs AC Motor Fans: Energy Savings & Payback
By longwell / September 20, 2026 / Fan Engineering Guides

EC vs AC Motor Fans: Energy Savings & Payback

An EC fan can save energy compared with an AC fan—but there is no hone...

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Forward-curved and backward-curved centrifugal wheels ready for selection
By longwell / September 20, 2026 / Fan Engineering Guides

Backward-Curved vs Forward-Curved: Which to Choose

Both wheels turn in a scroll and both move air outward, yet they suit ...

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Centrifugal vs Axial Fan: Pick the Right One
By longwell / September 19, 2026 / Fan Engineering Guides

Centrifugal vs Axial Fan: Pick the Right One

Axial and centrifugal fans are not selected by shape alone. This video...

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Plug fan without scroll housing next to a traditional housed centrifugal fan
By longwell / September 19, 2026 / Fan Engineering Guides

Plug Fan vs Housed Fan (Scroll) Comparison

A plug fan drops the scroll and blows straight into the plenum. That c...

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Fan Wall vs Single Large Fan for AHU
By longwell / September 19, 2026 / Fan Engineering Guides

Fan Wall vs Single Large Fan for AHU

One large fan is simple. A fan wall adds modules, control options and ...

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Metal vs Plastic Impeller: Durability & Cost
By longwell / September 19, 2026 / Fan Engineering Guides

Metal vs Plastic Impeller: Durability & Cost

Metal is not automatically durable, and plastic is not automatically c...

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