Johns Manville Releases the First Flexible R-12 Fiberglass Duct Liner

Johns Manville is proud to announce its release of the first ever flexible fiberglass duct liner with an R-12 thermal resistivity rating. This innovative insulation is designed specifically to meet the new code requirements set forth by the IECC in 2015 that mandate the use of R-12 insulation on ducts in unconditioned spaces in climate zones 5-8.

Johns Manville’s HVAC Product Manager, Brennan Hall, explained that this new three-inch liner should be highly valuable to contractors working in those climate zones. “Prior to our new Linacoustic RC product, single-layer, flexible R-12 duct liner was not an available option for the market. As a result, contractors have been forced to use two layers of insulation to meet the R-12 standard. This is costly in terms of materials as well as labor. Our new R-12 duct liner meets the code in just one layer, and offers the same high-quality performance our customers have come to expect from Johns Manville’s Linacoustic product line,” he said.

Johns Manville’s duct liner is known for being easy to work with and fabricate. Their unique flame-attenuated manufacturing technology creates a fiberglass core that can be processed consistently and efficiently on duct fabrication equipment, like a RotoZip machine or a water jet cutter.

Additionally, this thermally robust duct liner has a glass-mat surface coated with Permacote®, an acrylic, antimicrobial coating designed to help protect the airstream surface. This coating serves a three-fold purpose. First, it helps create a more durable airstream surface. Second, the coating helps guard against dust or dirt entering the substrate, minimizing the potential for microbial growth. Third, the reinforced coating surface provides superior resistance to incidental water penetration into the fiberglass wool core.

For more information on Linacoustic RC, three-inch duct liner, please visit

About Johns Manville 

Johns Manville, a Berkshire Hathaway company (NYSE: BRK.A, BRK.B), is a leading manufacturer and marketer of premium-quality building and specialty products. In business since 1858, the Denver-based company has annual sales of $3 billion and holds leadership positions in all of the key markets that it serves. Johns Manville employs 7,500 people and operates 43 manufacturing facilities in North America, Europe and China. Additional information can be found at