Research on the Diversity of Shapes in Fabric Ducts

        Fabric ducts, as an innovative alternative to traditional metal ducts, are revolutionizing the HVAC industry with their unique material properties and design flexibility. They offer silent, energy-efficient, and uniform air distribution solutions. This paper systematically studies various shapes of fabric ducts, analyzing their aerodynamic characteristics, application scenarios, and market promotion strategies, revealing the decisive impact of shape diversity on the performance and application scope of fabric ducts. The research shows that different shaped fabric ducts can provide optimal solutions for specific applications, while scientific marketing strategies are key to promoting this innovative technology.

            I. Fabric Ducts: From Single Form to Multiple Designs

       1.1 Development History

       Fabric ducts (also known as cloth ducts or SoxAir ducts) originated in Europe in the 1970s, initially designed to solve condensation and hygiene issues caused by traditional metal ducts in food processing plants. Early products were mostly simple circular structures with limited functionality and application scope. With advancements in materials science, aerodynamics, and textile technology, fabric ducts have evolved from single circular forms into diversified shape systems capable of meeting various air distribution needs from industrial plants to high-end commercial spaces.

       1.2 Drivers of Shape Diversification

Shape diversification is a core trend in the development of fabric duct technology, driven mainly by:

• Spatial Adaptation Needs: Modern architectural spaces vary greatly, requiring flexible duct systems.
• Aerodynamic Optimization: Different shapes significantly affect airflow organization, resistance loss, and air delivery distance.
• Visual Aesthetics: Ducts are transitioning from hidden equipment to visible decorative elements.
• Functional Specialization: Specific applications require customized air delivery modes.
• Installation Convenience: Adapting to various installation conditions and construction limitations.

             II. Study on the Shape System and Characteristics of Fabric Ducts

       2.1 Traditional Circular Ducts

Structural Features: Fully circular cross-section, the most basic and widely used shape.

Aerodynamic Characteristics:

• Uniform airflow distribution, minimal internal friction resistance.
• Symmetrical static pressure distribution, facilitating uniform placement of various types of air outlets.
• Typical diameter range: 200-1500mm.
• Friction coefficient: 0.024-0.032 (lower than traditional metal ducts' 0.019, but through static pressure recovery effect, total system resistance is lower).

Application Scenarios: Large stadiums, industrial plants, warehouses, and other open spaces with heights ≥4m.

Market Share: Approximately 65% of the fabric duct market, currently the mainstream shape.

       2.2 Semi-Circular Ducts

Structural Features: Semi-circular cross-section, typically installed along walls or ceilings.

Aerodynamic Characteristics:

• Utilizes Coanda effect to allow airflow to adhere to flat surfaces.
• Effective air delivery distance increases by 15-20% compared to full circles.
• Airflow coverage is more concentrated in the lower area.
• Uneven static pressure distribution requires targeted design of outlet positions.

Application Scenarios: Commercial spaces along walls, meeting rooms, restaurants, and retail stores with limited height (2.8-4m).

Innovative Application: In a high-end shopping mall's atrium, semi-circular ducts are installed along glass curtain walls, achieving unobtrusive air delivery while maintaining visual transparency.

        2.3 Custom-Shaped Ducts

Structural Features: Non-standard shapes customized based on building space and functional needs, such as triangular, polygonal, irregular curved shapes, etc.

Aerodynamic Characteristics:

• Requires CFD simulation optimization of internal flow fields.
• Highly customized design of air outlets.
• Complex static pressure distribution, requiring segmented calculations.
• Resistance characteristics are difficult to predict, often requiring prototype testing.

Application Scenarios: Iconic buildings, creative commercial spaces, special industrial equipment, stage art installations, etc.

              III. Scientific Basis for Shape Selection

       3.1 Key Decision Parameters

Choosing the right shape of fabric duct involves comprehensive consideration of the following parameters:

• Spatial geometric characteristics: Ceiling height, floor plan shape, obstacle distribution.
• Air delivery requirements: Delivery distance, coverage area, temperature uniformity.
• Airflow organization: Vertical/horizontal air delivery, displacement ventilation/mixed ventilation.
• Installation conditions: Suspension space, load-bearing capacity, maintenance channels.
• Aesthetic requirements: Visible/hidden installation, color, shape integration.
• Economic considerations: Material costs, installation costs, operational energy consumption.

              IV. Conclusion

      The diversity of shapes in fabric ducts is not only a technological advancement but also a revolutionary innovation in traditional ventilation concepts. From simple circles to complex custom shapes, each form represents a response to specific spaces and needs. As materials science, computational fluid dynamics, and intelligent manufacturing technologies develop, fabric ducts will break through morphological limitations to become key elements in architectural spaces that combine functionality and aesthetics. Promoting this innovative technology requires joint efforts from all sectors of the industry: manufacturers need to continuously innovate materials and processes; design institutes need to embrace new concepts, transforming ducts from "hidden equipment" to "visible design elements"; owners need to evaluate value from a lifecycle perspective; industry organizations need to improve standards and establish quality assurance systems. When a duct is no longer just a conduit for air but becomes a smart entity capable of sensing the environment, adapting to needs, integrating aesthetics, and even expressing emotions, what we change is not only the method of air delivery but also the interactive relationship between people and architectural spaces. The shape revolution of fabric ducts vividly embodies this transformation.