Acoustic Duct Liner

SilentFiber™ Acoustic Duct Liner provides acoustic fiberglass insulation for circular metal ducts. Duct Liner can be used in both commercial and residential acoustical construction projects.


SilentFiber™ Acoustic Duct Liner insulation is designed to be applied to interior surfaces of sheet metal duct work for HVAC systems in residential and commercial applications. This productcCan also be used for insulation of appliances. Manufactured from fiberglass wool combined with a thermo-resistant resin with an interior coating that is reinforced with fiberglass.

To create a water-resistant and damage-resistant cure, apply Foster® 40-23 Duct Liner Insulation Sealer to the SilentFiber™ Acoustic Duct Liner after installation with a brush or airless sprayer.

Product can be applied inside the sheet metal duct work for air systems operating at temperatures from 5°C (40°F) and 121°C (250°F), with the facing exposed to the airflow. The insulation shall be secured to the sheet metal duct work using mechanical fasteners (impact-driven or weld secured) or an appropriate supporting tool.


  • NRC: 0.7 (1 inch) and 0.8 (2 inches)
  • Pounds per cubic foot: 1.5t
  • R-Value: 4.1 (1 inch) and 7.7 (2 inches)
  • Maximum air temperature: 121°C (250°F)
  • Thermo-resistance: R=4.3 (H.°F ft²/BTU)

Approved Standards:

  • ASTM C1338-00
  • ASTM CM411-05
  • ASTM C665
  • ASTM C795
  • ASTM 1304
  • UL723
  • ASTM C916
  • ASTM E84
  • ASTM C177
  • ASTM C423
  • ASTM C167

This product will require transportation via LTL carrier. Please contact us for shipping options at 1-877-399-9697.

Weight N/A
Dimensions N/A

1 inch, 2 inches


100 feet x 4 feet, 50 feet x 4 feet