The question “Which is better, a centrifugal fan or an impeller fan?” mixes two different ideas. Every fan has an impeller (the rotating wheel), so the term “impeller fan” usually refers to a simple propeller or axial fan where the blades look like a propeller and move air straight through the fan. A centrifugal fan has an impeller that throws air outwards into a scroll casing, changing the direction of flow. Neither type is always better; each is superior in specific applications.
A centrifugal fan is generally better when the system has higher resistance. It can develop more static pressure than a similar-size propeller fan, making it suitable for long or complex duct systems, dust collectors, scrubbers and combustion air or flue gas duties. Radial and backward-curved centrifugal fans handle dusty, abrasive or hot gases well and are widely used in heavy industrial and mining ventilation for local exhaust, dust extraction and process air where the air must turn through 90 degrees into ductwork.
An impeller or propeller fan (axial fan) is usually better when you want very high airflow at low to medium pressure with a straight-through path. These fans move air parallel to the shaft and are efficient for applications such as large hall ventilation, tunnel and shaft airflow, condenser cooling and simple wall or roof exhaust. In main mine ventilation or tunnel ventilation, large axial fans are often used because they can move massive volumes of air through long airways with comparatively low pressure drop per metre.
When deciding which is better for your project, consider airflow, pressure, air quality and layout:
- If you have long ducts, filters, heat exchangers or high-resistance equipment, a centrifugal fan is usually the better choice.
- If you primarily need bulk airflow through relatively straight shafts, drifts or open buildings, an axial or propeller style “impeller fan” is often more efficient.
- If the air is dirty, dusty or abrasive, rugged radial-blade centrifugal fans provide greater reliability than light propeller fans.
In summary, a centrifugal fan is better for higher-pressure, dusty or ducted systems, while a propeller-type impeller fan is better for large volumes of air at lower pressure in open or straight-through ventilation. The best choice depends on the duty, not on a simple label.
