Vane Axial vs. Centrifugal Fans

Selecting the best fan for an application begins with choosing the right fan architecture. The appropriate fan architecture can be determined from the performance requirements or specific SWaP-C metrics. Fan architecture refers to the type of fan, such as vane-axial or centrifugal, and each type has its own advantages and disadvantages. By determining whether an application is better suited for a vane-axial or centrifugal fan solution, an engineer can select a fan solution that satisfies the application’s performance requirements while ensuring good efficiency, installation, and noise characteristics.??

Vane-axial fans are best-suited for high flow and medium to low pressure applications where the incoming and outflowing air moves parallel to?the axis of rotation. This fan architecture is comprised of inlet, impeller, guide-vane, and diffuser sections. The air enters through the inlet section, and after experiencing the speed and pressure rise imparted by the impeller is then directed through a set of guide vanes which straighten out the swirling airflow leaving the impeller. De-swirling the air reduces the absolute velocity and increases the potential energy (pressure) of the airstream. The diffuser section’s geometry then further assists with decelerating the airflow and recovering kinetic energy in the form of static pressure. A vane axial fan should be selected when the application calls for medium to low pressure rise. The engineer must ensure that when installed, the selected fan will operate with sufficient margin to its stall boundary to realize the expected aerodynamic performance. Depending on rotational speeds, production volumes, and other considerations, the impeller may either be a cast or machined component. Vane axial fans generally have a compact space claim while the overall length may vary based on motor selection and diffuser geometry. These fans can be either shaft-driven or motor driven depending on the application.?

Centrifugal fans are best suited for lower flow and high pressure applications or when a change of direction is needed between the incoming and outflowing air. These fans operate using the principle of centrifugal acceleration: the air coming into the fan inlet is accelerated radially outward by the impeller, causing the airflow to move outwards from the impeller hub towards a duct or volute. Centrifugal fans have high efficiency over a broad range and may be designed to have a stall-free characteristic which makes them especially useful for systems with variable back pressure elements like filters or valves. Centrifugal fan designs also offer the inherent advantage of redirecting the flow 90° which can often be a useful variability when considering system arrangement and packaging, however this characteristic is not absolute (axial-flow centrifugal fans do exist). Like vane-axial fans, these fans can be designed to be either shaft or motor driven.?

The above fan architectures described are embodied by Xcelaero’s vane-axial fan series, the Force and Galeforce Fan Series, and centrifugal fan series, the Helios Fan series. When considering all three families, Xcelaero offers fan solutions that extend across a vast range of performance cases. As illustrated in the graph above, Xcelaero fans can provide anywhere between 10’s to 10,000’s CFM of airflow and pressure rise capabilities as great as 45.0 in. WCg. The Force Fan series are fans optimized for manufacturability and low cost. The Galeforce Fan series are fans optimized for low noise, high efficiency, and low weight. The Helios Fan series are optimized for high-pressure applications. Our team is also fully capable of developing a custom fan solution to best fit your application and system needs. To learn more about our fan families or to inquire about a custom fan solution, please submit an email inquiry at [email protected].?