Flex KM is a thermally insulated, fully lined, UL 181 Class 1 flexible air duct designed for low to medium pressure cooling and heating HVAC systems. It can be used in either supply or return sections and provides economical means for handling misalignment between systems components and ducting around obstacles where fabricated and fitted ducts are difficult and costly to use. It is equally suitable for new jobs or retrofit work and is especially useful when making system extensions or for changing conditioned zones, now or in the future.
Compliance to NFPA Standards allows you to install lengths longer than the 14' limitation applying to connectors. It is a highly efficient part of the total duct system because the smooth liner, the ample insulation and tough outer vapor barrier provide good airflow, thermal insulation and a double air seal
Features and Benefits:
Underwriters Laboratories listed for the US and Canada.
Complies with NFPA Standards 90A and 90B.
Corrosion resistant steel wire helix.
Fully lined for efficient air delivery.
The outer vapor barrier is a jacket of fiberglass scrim reinforced metallized film laminate.
Quality KM installations produce referrals that increase volume and profits.
Available in 4.2, 6.0, and 8.0 thermal application values.
Available in both box and bag packaging.
GreenGuard® Gold Certified which is the industry’s most recognized Indoor Air Quality (IAQ) rating.
Made with Owens Corning™ EcoTouch® formaldehyde-free Insulation. Made with 99% natural materials and highest recycled content. Also, it is the only fiberglass insulation listed in the USDA BioPreferred Catalog.
25 Pounds (lbs)
12 Inches (In)
18.625 Inches (In)
Country of Origin
UPC or Barcode
EPA Cert Required
18.625 Inches (In)
Greenguard, GreenGuard Children & Schools, Greener Product, CHPS Member
UL Listed - USA & CAN
NFPA 90 A and 90 B
Laminated Polyester Film
Complies With Nfpa Standards 90A And 90B. Corrosion Resistant Steel Wire Helix. Fully Lined For Efficient Air Delivery. The Outer Vapor Barrier Is A Jacket Of Fiberglass Scrim Reinforced Metallized Film Laminate.