Fan Engineering Guides

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

Soft starter and VFD panel controlling a large industrial fan
By longwell / September 8, 2026 / Fan Engineering Guides

Soft Starter vs VFD vs DOL for Big Fans

Large fan wheels have serious inertia, so how you start them matters. ...

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Ball bearings and sleeve bearings from fan motors compared
By longwell / September 8, 2026 / Fan Engineering Guides

Ball vs Sleeve Bearings: When to Replace

Sleeve bearings are quiet and cheap until they dry out. Ball bearings ...

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Thermal overload protector inside a fan motor winding
By longwell / September 8, 2026 / Fan Engineering Guides

Fan Thermal Overload Protection Explained

A tripping thermal protector is doing its job, and it is also telling ...

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Fan motor nameplate showing voltage, current and insulation class
By longwell / September 8, 2026 / Fan Engineering Guides

How to Read a Fan / Motor Nameplate

A nameplate contains everything you need to order a replacement and di...

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How to reverse a fan motor by swapping two supply leads at the terminal
By longwell / September 8, 2026 / Fan Engineering Guides

How to Reverse a Fan Motor’s Direction

Reversing rotation is straightforward on some motors and impossible on...

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EMC for EC fans: earthing and screened control cable at a fan terminal box
By longwell / September 8, 2026 / Fan Engineering Guides

Grounding & EMC for EC Fans

An EC fan is a switching converter bolted to an impeller. That makes e...

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Modbus RTU RS-485 wiring connecting a network of EC fans
By longwell / September 8, 2026 / Fan Engineering Guides

Modbus RTU for Fan Networks — Basics

Modbus turns an array of fans into a set of visible, individually cont...

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EC fan with built-in electronics visible behind the motor housing
By longwell / September 7, 2026 / Fan Engineering Guides

Why EC Fans Have Built-in Electronics

A brushless motor cannot run without electronics, so the only question...

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Buyer checking a batch before agreeing to buy industrial fans from a factory
By longwell / September 7, 2026 / Fan Engineering Guides

How to Buy Industrial Fans from China Safely

Sourcing from China works well when the process is structured. Verify ...

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OEM vs ODM fan samples with private label branding options
By longwell / September 7, 2026 / Fan Engineering Guides

OEM vs ODM vs Private Label Fans

The three routes differ in who owns the design and who carries the ris...

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