When designing fabric ductwork, several key parameters and considerations need attention:

Airflow and Velocity:

1. Airflow: Determine the required air volume, typically measured in cubic meters per hour (m³/h) or cubic feet per minute (CFM).

2. Air Velocity: Calculate air velocity based on airflow and the cross-sectional area of the fabric duct. Maintain suitable air velocity to minimize pressure loss and noise.

Pressure Loss:

1. Duct Resistance: Calculate the resistance of each duct segment to ensure pressure loss at design airflow remains within permissible limits. Pressure loss directly impacts system energy efficiency and operational costs.

Duct Size and Shape:

1. Cross-sectional Shape and Size: Select appropriate shapes (e.g., round, rectangular) and sizes of fabric ducts to meet airflow and velocity requirements, considering installation space and layout constraints.

Material and Fire Performance:

1. Duct Material: Choose materials compliant with safety and fire standards, such as fiberglass or polyester fibers, to ensure safe operation.

2. Fire Performance: Pay particular attention to the fire performance of duct materials, selecting appropriate fire ratings according to local building codes and safety standards.

Fabric Connections and Sealing:

1. Connectors and Seals: Use high-quality connectors and seals to ensure proper sealing at duct joints, reducing air leakage and energy losses.

Noise Control:

1. Sound Absorption: Incorporate sound absorption materials where necessary, especially at bends or joints, to minimize noise generated by the system.

System Integration and Maintenance:

1. Overall System Integration: Ensure fabric ducts integrate well with other components of HVAC systems (e.g., air handling units, diffusers), maintaining overall efficiency and stability.

2. Maintenance Requirements: Consider maintenance needs during design to facilitate cleaning and upkeep, prolonging system lifespan and performance.

In summary, designing fabric ductwork requires careful consideration of airflow, pressure loss, duct size and shape, material selection, fire performance, connections and sealing, noise control, system integration, and maintenance requirements to ensure safe, efficient operation over the long term.