KoolDuct Lined Metal Ductwork

HVAC Duct Liner Insulation for Indoor or Outdoor Use

Sheet Metal Connectors now offers KoolDuct® lined metal ductwork, which is easier to install and simpler to handle than traditional 3” doublewall insulated sheet metal. This HVAC duct liner comes pre-insulated and is suitable for indoor and outdoor applications. Used as a liner in ductwork, this product has higher R values and closed-cell insulation. KoolDuct lined duct is available in R-8, R-12, R-16, and R-20 to meet your specification.

Phenolic Duct Insulation That’s Convenient and Efficient

KoolDuct lined metal ductwork weighs less than doublewall insulated sheet metal and achieves a higher R-Value in less space. R-12 KoolDuct is only 1.75” thick compared to 3” for R-12 fiberglass liner. With its high R values, virtually no air leakage, lightweight convenience, and shorter installation time, KoolDuct is a good choice for a range of indoor and outdoor air distribution applications, especially budget-minded rooftop ductwork. KoolDuct phenolic duct is suitable for new and retrofit commercial, light industrial and institutional projects.

KoolDuct reduces air-leakage rates to a fraction of standard rectangular sheet metal ductwork and is significant in three key areas: cutting costs, slashing energy use and trimming operational carbon dioxide emissions.

HVAC Duct Liner Insulation With High R Values

With the highest R-value-to-size ratio in-market, KoolDuct panels are available in the following thicknesses and installed R-values:

  • R-8.1 (1x 1 3/16″ Panel)
  • R-12 (1 x 1 3/4″ Panel)
  • R-16.2 (2 x 1 3/16″ Panel)
  • R-20 (1 x 1 3/4″ Panel, 1 x 1 3/16″ Panel)
  • R-24 (2 x 1 3/4 Panel)

KoolDuct phenolic duct insulation benefits include:

  • Installs faster than other duct liner insulation, saving time and money
  • Saves energy by reducing air leakage in comparison to standard insulated metal
  • Can be easily modified and adjusted to deal with onsite design changes
  • Fiber-free insulation core to minimize loose fibers entering the airstream


Ductwork that’s fabricated using KoolDuct will meet and exceed 2020 SMACNA duct construction standards and requirements. This duct liner insulation, which is UL listed as a Class 1 Air Duct Standard for Safety UL 181, also complies with NFPA Standards 90A and 90B.

All SMC custom sheet metal products, including KoolDuct phenolic lined metal ductwork, are designed and manufactured in our yellow-label union shop.