Centrifugal Fans

Centrifugal fans build pressure by accelerating air outward through a rotating impeller, making them the workhorse for HVAC air handlers, cleanrooms, dust collection and process ventilation. Articles under this tag cover working principles, backward vs forward curved impellers, performance-curve reading, selection math and maintenance practice, with LONGWELL AC/DC/EC centrifugal fan data for reference.

Curve showing where centrifugal fans surge, left of the pressure peak
By longwell / September 10, 2026 / Fan Engineering Guides

Why Do Centrifugal Fans Surge? (Stall Explained)

Surge is what happens when a fan is pushed too far left on its curve. ...

Read More »
Airfoil impellers with aerofoil section blades in a centrifugal fan
By longwell / September 10, 2026 / Fan Engineering Guides

Why Airfoil Impellers Are the Most Efficient

Airfoil blades reach the highest static efficiency of any centrifugal ...

Read More »
Volute cutoff clearance shown between the scroll tongue and the wheel
By longwell / September 10, 2026 / Fan Engineering Guides

Volute / Scroll Housing & Cutoff Design

The scroll does half the work in a centrifugal fan, and the cut-off de...

Read More »
Fan inlet cone and venturi ring guiding air into an impeller
By longwell / September 10, 2026 / Fan Engineering Guides

Inlet Cone & Venturi: Small Part, Big Efficiency

The inlet cone is a cheap pressing that decides how cleanly air enters...

Read More »
Axial, mixed-flow and centrifugal fan impellers compared side by side
By longwell / September 5, 2026 / Fan Engineering Guides

Axial vs Mixed-Flow vs Centrifugal

Mixed-flow fans sit between axial and centrifugal, delivering roughly ...

Read More »
Single inlet and double inlet centrifugal fan wheels compared
By longwell / August 21, 2026 / Fan Engineering Guides

Single Inlet vs Double Inlet Centrifugal Fans: What are different?

A double inlet wheel takes air from both sides, roughly doubling airfl...

Read More »
Plenum fan mounted on a bulkhead inside an air handling unit
By longwell / August 21, 2026 / Fan Engineering Guides

Plenum (Plug) Fan vs Housed Fan for AHU

A plenum fan blows into the cabinet rather than into a scroll. That co...

Read More »
longwell dry-type transformer cooling solution
By longwell / August 19, 2026 / Engineering Case Studies

Integrated Fan Cooling for Ultra-High-Power Dry-Type Transformers

Thermal management has become the engineering challenge in dry-type tr...

Read More »
longwell-lwbe3g450-102ps-24-pr
By longwell / August 19, 2026 / Engineering Case Studies

230V EC Centrifugal Fan Project: Modbus V3.0 and Custom Mounting

Read how we adapted a 230V EC centrifugal fan for a commercial unit. W...

Read More »
LONGWELL centrifugal fan
By longwell / August 11, 2026 / Technical Articles

Centrifugal HVAC Fans: Complete Ordering Guide

Centrifugal fans are widely used in AHUs, ventilation equipment, and H...

Read More »