North American terms: fabric ducts, duct sox, air socks

In the United States and Canada, “fabric ducts” and “fabric air ducts” are the common professional terms, while “duct sox” and “air socks” are the everyday shorthand you’ll hear on job sites and in casual conversation. The “sock” and “sox” names caught on because the fabric tube’s soft, suspended appearance resembles a sock — and, over time, an early brand name in the space helped push “sox” into general use. Today American engineers, contractors, and facility managers use these terms more or less interchangeably.

European terms: textile ducts

Across much of Europe, the same systems are usually called textile ducts or textile air ducts. The emphasis on “textile” reflects a more technical, material-focused naming convention common in European HVAC specification. If you’re reading a European product sheet or standard, “textile duct” and “fabric air duct” mean exactly the same thing.

Which term should you use?

For clarity in specifications and documentation, “fabric air ducts” is the safest choice — it’s descriptive, widely understood on both sides of the Atlantic, and not tied to any single brand. In everyday conversation, “duct socks” and “air socks” are perfectly clear to most North American professionals. What matters is recognizing that none of these names signals a different product, performance level, or manufacturer — they’re all the same engineered fabric air dispersion system.

The bottom line

The terminology varies by region and habit, but the technology is one and the same. When you’re comparing options, focus on the fabric specification, flow model, and manufacturer’s track record rather than the label on the datasheet. For a full overview of the product, applications, and how the systems are built, see our duct socks overview.

Grey fabric air duct in a swimming pool facility, US

FAQ

Fabric ducts, duct socks, and air socks generally refer to the same type of technology: a textile-based air distribution system used as an alternative to conventional metal ductwork. The terminology varies by region, industry, and context, but the basic principle is the same — air is distributed through engineered fabric rather than through metal ductwork and separate diffusers.

Related terms: duct socks and air socks, fabric air ducts, fabric air dispersion, textile ductwork

In the U.S., “fabric ducts” and “fabric air ducts” are common technical terms, while “duct socks” and “air socks” are widely used informal alternatives. Other terms, such as material ducting or textile ducting, may also appear depending on the industry or project.

Related terms: duct socks, fabric air ducts, material ducting, air socks, textile ducting

The nickname comes from the lightweight, flexible shape of the fabric duct, which resembles a long textile sleeve or sock when it is not pressurized. The terminology became common on job sites and is now widely recognized across the HVAC industry.

Related terms: air socks, fabric duct terminology, flexible ducting, textile air distribution, material ducting

The terms are often used interchangeably, but project specifications should still clearly define the required system, materials, airflow performance, suspension, and other components. Using precise terminology helps engineers, contractors, and manufacturers understand exactly what is being specified.

Related terms:
project specification, fabric air duct components, duct profiles, flow models, fabric air dispersion

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