Flexible Ducts

Flexible ducts provide a bendable path for directing air in commercial HVAC, ventilation, portable cooling, portable heating, exhaust, and recirculation applications. Facilities teams, installers, and maintenance crews use them to make air-routing connections where fixed ductwork is not the right fit, including heating and cooling runs, dryer and bathroom applications, temporary blowing or exhaust setups, ceiling connections, and confined-space ventilation work.

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Helpful Buying Guide

Flexible Ducts: Find the Right Fit for Your Air-Routing Job

Flexible ducts bridge the gap between fixed ductwork and the equipment or spaces that need airflow. Whether you're running an HVAC connection, venting a dryer, exhausting fumes, or setting up temporary cooling, the right flexible duct matches your diameter, length, construction, and environment.

Visual Guide

Popular examples in this category

12-Inch Diameter Flexible Duct, 25 Ft., Yellow12-Inch Diameter Flexible Duct, 25 Ft., YellowWBB66432714-Inch Non-Insulated Flexible HVAC Duct14-Inch Non-Insulated Flexible HVAC DuctWBB3569218-Inch Diameter Flexible HVAC Duct18-Inch Diameter Flexible HVAC DuctWBB3563916 in. Diameter x 32 ft. Yellow/Black Flexible PVC Duct16 in. Diameter x 32 ft. Yellow/Black Flexible PVC DuctWBB3168250
What These Products Are For

Where Flexible Ducts Get Used

Flexible ducts handle air routing where rigid ductwork won't work. Common uses include HVAC heating and cooling runs, dryer and bathroom ventilation, portable air conditioner and heater connections, exhaust setups, ceiling drops, and confined-space ventilation where a bendable path is needed.

How To Choose

Matching the Duct to the Job

Start with diameter and length requirements, then consider insulation needs, connection style, and environment. HVAC runs may need insulated or acoustically lined options. Portable equipment needs equipment-matched sizing. Outdoor or exhaust applications call for UV, mold, and mildew resistant constructions.

Common Applications

Applications Across Facilities and Job Sites

Facilities teams use flexible ducts for HVAC trunk connections, bathroom and dryer exhaust, temporary blowing or recirculation setups, ceiling plenum connections, and confined-space air supply. Installers and maintenance crews rely on them for quick, adaptable routing without cutting into fixed duct systems.

Additional Information

Construction Features Worth Knowing

Steel-wire helixes maintain duct shape under airflow pressure. Wearstrips protect against abrasion in high-contact runs. End cuffs simplify connections. Compressible designs save storage space. Insulated options with acoustic inner liners reduce noise in occupied spaces. PVC constructions suit ventilation and exhaust environments.

12" to 20"Diameter Range Available

Flexible ducts in this category span 12-inch through 20-inch diameters to cover portable equipment, HVAC, and industrial ventilation needs.

R-4.2Insulation Rating

The insulated HVAC duct option carries an R-4.2 rating, helping reduce heat loss along longer heating and cooling runs.

Acoustic LinerNoise Reduction Feature

The 14-inch insulated option includes an acoustic inner liner designed to reduce airflow noise in occupied or noise-sensitive spaces.

PVC + Steel HelixVentilation Duct Construction

Ventilation and exhaust ducts use PVC construction reinforced with a steel-wire helix to maintain shape and resist collapse under airflow pressure.

Comparison Guide

Choosing the Right Flexible Duct by Application

Use this table to match your application type to the best duct construction and key features.

ApplicationBest FitWhy It Matters
HVAC heating or cooling run, standard14" or 18" non-insulated flexible ductSized for common HVAC collar diameters with flexible routing in conditioned spaces
HVAC run requiring heat retention or quiet airflow14" insulated R-4.2 with acoustic linerReduces heat loss and dampens airflow noise along longer or noise-sensitive runs
Portable air conditioner connection12" duct matched to equipment specsPortable cooling units require specific diameter matches at the exhaust collar
Portable heater connection20" heater ductingLarger diameter handles higher airflow volumes typical of portable heating equipment
Ventilation, exhaust, or outdoor-facing run16" or 20" PVC with steel-wire helixUV, mold, and mildew resistance plus shape retention suit exhaust and outdoor environments
Planning Guide

Plan the right fit before choosing

Planning Guide

Step 1: Confirm Diameter and Length Before You Order

Diameter is the most critical starting point. Mismatched sizing means the duct won't connect to your equipment or existing ductwork. Measure the collar or port on both ends of the intended run, then select a duct that matches. Available diameters include 12-inch, 14-inch, 16-inch, 18-inch, and 20-inch options depending on application type.

  • HVAC applications: 14-inch and 18-inch non-insulated, plus 14-inch insulated R-4.2
  • Portable cooling and heating: 12-inch and 20-inch options sized to equipment specs
  • Ventilation and exhaust: 16-inch and 20-inch PVC constructions
  • Measure both connection points before selecting length to avoid over-stretching
Planning Guide

Step 2: Match Construction to Environment and Performance Needs

Not all flexible ducts are built for the same conditions. Non-insulated ducts work for basic air routing in conditioned spaces. Insulated options with R-4.2 ratings reduce heat loss and are better for longer HVAC runs. Acoustic inner liners help in noise-sensitive areas. PVC constructions with UV, mold, and mildew resistance are suited for outdoor or exhaust-facing applications.

  • Non-insulated: general HVAC connections in conditioned spaces
  • Insulated R-4.2 with acoustic liner: longer runs or noise-sensitive environments
  • PVC with steel-wire helix: ventilation and exhaust where shape retention matters
  • UV, mold, and mildew resistant: outdoor-facing or high-humidity exhaust paths
Planning Guide

Step 3: Account for Installation Components and Storage

Check whether the duct includes installation components such as end cuffs or connection hardware, or whether those need to be sourced separately. For jobs where storage space is limited, compressible duct designs collapse down when not in use. Wearstrips are worth selecting when the duct will run through areas with contact or abrasion risk.

  • End cuffs included on some models simplify connection to collars and ports
  • Compressible designs are practical for maintenance crews storing multiple duct lengths
  • Wearstrips extend service life in high-contact or dragged-across-floor applications
  • Confirm connection style compatibility with existing equipment before ordering
FAQ

Common questions before buying

How do I know which diameter flexible duct to order?

Measure the collar or port opening on both pieces of equipment or ductwork you're connecting. The flexible duct diameter must match both ends. Available sizes in this category include 12-inch, 14-inch, 16-inch, 18-inch, and 20-inch options depending on application type.

Do I need an insulated flexible duct for my HVAC application?

Insulation matters most on longer runs or in unconditioned spaces where heat loss is a concern. The 14-inch insulated R-4.2 option also includes an acoustic liner, making it a good choice when noise reduction is a priority. Shorter runs in conditioned spaces can typically use non-insulated duct.

Can I use a standard HVAC flexible duct for exhaust or ventilation applications?

Not always. Exhaust and ventilation environments often involve higher humidity, outdoor exposure, or fume contact. PVC constructions with UV, mold, and mildew resistance and steel-wire helixes are specifically built for those conditions and hold up better than standard HVAC duct in those settings.

What does a steel-wire helix do in a flexible duct?

The steel-wire helix runs through the duct wall in a spiral pattern to maintain the duct's round shape under airflow pressure. Without it, the duct can kink or collapse, restricting airflow. It's a key feature in ventilation and exhaust ducts where shape retention under load is important.

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