Fan Engineering Guides

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

Static Pressure Calculation for Duct Systems
By longwell / September 18, 2026 / Fan Engineering Guides

Static Pressure Calculation for Duct Systems

Calculate duct static pressure as a traceable loss ledger—not a guess....

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EC fan for AHU retrofit installed in place of a belt driven centrifugal fan
By longwell / September 18, 2026 / Fan Engineering Guides

How to Choose an EC Fan for AHU Retrofit

Retrofitting an old belt-driven AHU fan with EC technology is one of t...

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Fan Motor Sizing: HP, Voltage & Full Load Amps
By longwell / September 18, 2026 / Fan Engineering Guides

Fan Motor Sizing: HP, Voltage & Full Load Amps

Size a fan motor from the real duty point—not from CFM alone. This wor...

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How Many Fans for a Fan Wall? N+1 Redundancy Explained
By longwell / September 18, 2026 / Fan Engineering Guides

How Many Fans for a Fan Wall? N+1 Redundancy Explained

Calculate fan-wall quantity with a real one-fan-unavailable check—not ...

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Airflow Unit Conversion: CFM ↔ m³/h ↔ L/s
By longwell / September 18, 2026 / Fan Engineering Guides

Airflow Unit Conversion: CFM ↔ m³/h ↔ L/s

Convert airflow without losing a factor of 60. This visual engineering...

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Selecting a Blower for Combustion / Burner Air
By longwell / September 18, 2026 / Fan Engineering Guides

Selecting a Blower for Combustion / Burner Air

A combustion blower cannot be selected from burner kilowatts alone. Th...

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Cleanroom Fan Filter Unit (FFU) Fan Selection
By longwell / September 17, 2026 / Fan Engineering Guides

Cleanroom Fan Filter Unit (FFU) Fan Selection

Selecting an FFU fan by open-air maximum flow can fail as soon as the ...

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How to Replace an Undersized Blower Without Redesign
By longwell / September 17, 2026 / Fan Engineering Guides

How to Replace an Undersized Blower Without Redesign

A stronger blower is only “drop-in” if the duty point, mechanical enve...

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How to Replace an AC Blower Motor (Full Guide)
By longwell / September 17, 2026 / Fan Engineering Guides

How to Replace an AC Blower Motor (Full Guide)

Replace an indoor AC blower motor by proving the fault, matching the e...

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HVAC Blower Motor Replacement — Cost & Steps
By longwell / September 17, 2026 / Fan Engineering Guides

HVAC Blower Motor Replacement — Cost & Steps

Compare HVAC blower motor replacement quotes by architecture, replacem...

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