Flexible Duct

Flexible duct is the go-to solution for routing air through tight spaces and around obstacles in HVAC systems. Built with a spring-steel wire helix and a durable inner liner, it often includes a fiberglass insulation layer with a foil or PVC jacket to maintain temperature, reduce condensation, and cut noise. Use it to connect supply and return trunks to diffusers, run bathroom and kitchen exhaust, or solve tricky retrofit challenges without extensive sheet metal work.

The benefits are clear: faster installation, fewer fittings, quieter airflow, and improved energy efficiency when properly sized and sealed. You can choose insulated flexible duct for unconditioned areas and uninsulated options for short, conditioned runs. Common diameters range from 4 to 16 inches; size by required CFM and allowable static pressure. Look for UL 181 listings (Class 1 air duct) and match R-value, jacket type, temperature rating, and pressure rating to your project and local code.

For reliable performance:
- Keep runs as short and straight as possible with gentle bends.
- Fully extend the duct without compressing or overstretching.
- Support at least every 4 feet with wide straps to prevent sagging.
- Maintain bend radii of one duct diameter or more to protect airflow.
- Seal all connections with mastic or UL 181 foil tape and secure with clamps or drawbands.
- Avoid crushing, sharp edges, and proximity to heat sources.

Helpful accessories include takeoffs, starting collars, boots, reducers, backdraft dampers, zip ties, and hanging hardware. For better indoor air quality, consider antimicrobial liners and low-VOC materials. Inspect periodically for tears, kinks, or moisture; repair or replace damaged sections to protect system efficiency.

Whether you’re a contractor or DIYer, quality HVAC flexible ducting streamlines air distribution for residential and light commercial work. Search for insulated flexible duct, flexible duct connectors, and duct fittings to match your ventilation, heating, and cooling needs and to optimize airflow, comfort, and noise reduction.