Fan Housing (Volute) Explained | Centrifugal Fan Efficiency

27.05.2025

When discussing the anatomy of an industrial fan, one of the most critical yet often overlooked components is the fan housing, also known as the volute. Whether you're dealing with high-pressure ventilation, fume extraction, or dust control, the design of the fan housing plays a pivotal role in system performance.

What Is a Fan Housing (Volute)?

The fan housing, or volute, is the outer casing that surrounds the impeller in a centrifugal fan. Its primary role is to capture and direct the air expelled from the rotating impeller and guide it toward the outlet efficiently.

Shaped like a spiral (similar to a snail shell or ammonite), the volute gradually increases in area from the point of air entry to the discharge point. This specific design allows it to harness the air's velocity and convert it into useful pressure.

Why the Volute Shape Matters

The volute is not just a protective casing; it’s a precision-engineered aerodynamic structure that:

• Channels airflow with minimal turbulence
• Increases static pressure for improved performance
• Reduces energy loss caused by friction and air leakage
• Enhances efficiency in systems with ductwork or filters

Its design also helps prevent recirculation and vibration, improving system stability and extending the fan’s lifespan.

The Role of Fan Housing in Centrifugal Fans

In centrifugal fans, the volute is essential for directing air at a 90-degree angle away from the impeller’s axis. The controlled airflow path ensures that velocity pressure is converted into static pressure as smoothly as possible, maximising output.

Key characteristics of high-quality fan housings:

• Tight clearance between blade tips and housing for pressure optimisation
• Smooth internal surfaces to reduce resistance
• Reinforced materials for high-temperature or corrosive environments
• Custom discharge positions to suit space and layout constraints

Choosing the Right Fan Housing Design

Depending on your application, fan housings can be customised to:

• Handle high-temperature or abrasive airflows
• Support multiple mounting configurations
• Integrate with duct systems or exhaust piping
• Accommodate inspection or maintenance ports

At Fans and Blowers, we engineer volutes to meet the unique demands of each system, whether you're dealing with food processing, manufacturing, or heavy-duty industrial extraction.

Why Fan Housing Quality Matters

Poorly designed or improperly installed housings can result in:

• Reduced airflow
• Increased system noise
• Higher energy costs
• Premature fan failure

By working with experienced manufacturers, you ensure the volute is optimised for your fan's impeller, motor, and airflow needs.