Atmosphere™ Air Duct Board

Atmosphere™ Air Duct Board

Knauf Insulation Atmosphere™ Air Duct Board with ECOSE® Technology is used to fabricate rectangular or Max10 air duct systems. It comes with two stiffness ratings, EI-475 and EI-800. Both types are available with butt edge or factory molded male-female shiplap edges. The airstream surface of Knauf Insulation Atmosphere Air Duct Board is treated with an EPA registered, anti-microbial agent that prevents growth of mold, fungus or bacteria in accordance with ASTM C1071, G21 and G22.

ECOSE® Technology

ECOSE Technology is a revolutionary binder chemistry that makes Knauf Insulation products even more sustainable. It is based on rapidly renewable bio-based materials rather than non-renewable petroleum-based chemicals traditionally used in fiberglass insulation products. ECOSE Technology reduces binder embodied energy and does not contain phenol, formaldehyde, acrylics or artificial colors.


Knauf Insulation Atmosphere Air Duct Board with ECOSE Technology is designed for commercial and residential air handling installations for cooling, heating or dual-temperature service where good temperature control and noise absorption are required.


  • Low thermal conductivity of 0.23 at 75°F (24°C) mean temperature.
  • Low installed cost insulated duct system.
  • Excellent acoustical characteristics.
  • Non-woven all-glass mat facing on airstream surface.
  • Assured insulation thickness, shiplap joints and FSK vapor retarder.
  • If necessary, can be cleaned in accordance with NAIMA’s “Cleaning Fibrous Glass Insulated Air Duct Systems Recommended Practices.”
  • Knauf Insulation Atmosphere Air Duct Board systems meet the fire and smoke safety regulations of most federal, state and local building codes.
  • Fabrication in shop or on jobsite.
  • Dark black glass mat airstream surface.
  • Certified for indoor air quality as a low emitting product by The GREENGUARD Environmental Institute to both the GREENGUARD Certification ProgramSM and the more stringent GREENGUARD Gold standard.
  • Sustainability
  • Carbon negative: meaning Knauf insulation products used for thermal insulating purposes recover the energy that it took to make them in just hours or a few days, depending on the application. Once installed, the product continues to save energy and reduce carbon generation as long as it is in place.
  • Glass mineral wool insulation with ECOSE Technology contains three primary ingredients:
    • Sand, one of the world’s most abundant resources
    • Post-consumer recycled bottle glass
    • ECOSE Technology which reduces binder embodied energy by up to 70%


  • Fabrication in shop environment lowers field installation time.
  • One craft required to fabricate and install system.
  • Minimum capital investment for fabrication equipment.
  • Portability allows for assembly or fabrication at job site.
  • Mat facing ensures a smoother airstream surface for a cleaner cut and added durability.
  • Lower installation cost than with duct wrap and duct liner with sheet metal.
  • Quiet, efficient air delivery.
  • Reduces noise generated by air turbulence and mechanical equipment.
  • Eliminates “booming” and “cracking” sounds caused by sheet metal duct contraction and expansion.
  • Condensation control.
  • Strong thermal performance.
  • Code compliance.

Specification Compliance

In Canada:

  • CAN/ULC S102-M88
  • CAN/CGSB 51-GP-52M (facing)
  • CAN/CGSB 51.10-92
  • In U.S.:
  • ASTM C 1136; Type II (FSK facing)
  • ASTM G 21, G 22
  • GREENGUARD Indoor Air Quality Certified®
  • California Title 24
  • Corps of Engineers Guide Specifications
  • International Mechanical Code
  • International Building Code
  • NFPA 90A and 90B
  • UL 181; Class 1

Technical Data

Surface Burning Characteristics

  • UL/ULC listed.
  • Does not exceed 25 Flame Spread, 50 Smoke Developed when tested in accordance with ASTM E 84, CAN/ULC S102-M88, NFPA 255 and UL 723.

Flexural Rigidity

  • Available in two stiffness values: EI-475 and EI-800.
  • Flexural rigidity (EI) is the product of Young’s modulus of elasticity (E) and moment of inertia (I) as determined in accordance with NAIMA AHS-100-74.

Service Temperature (ASTM C 411)

  • Up to 250°F (121°C).

Air Velocity (UL 181)

  • Maximum 5000 fpm (1524 mpm).
  • Tested to 12,500 fpm (3810 mpm).

Corrosiveness (ASTM C 665)

  • Does not accelerate corrosion on steel, copper or aluminum.

Corrosion (ASTM C 1617)

  • The corrosion rate in mils/yr will not exceed that of the 1 ppm chloride solution.

Internal Static Pressure (UL 181)

  • Maximuzm ±2” water (498 pascals [Pa]).

Water Vapor Transmission Rate (ASTM E 96)

  • Less than 0.02 perms.

Water Vapor Sorption (ASTM C 1104)

  • Less than 5% by weight.

Microbial Growth (ASTM G 21, G 22, UL 181)

  • Does not promote or support the growth of mold, fungi or bacteria.

Application and Specification Guidelines


  • Protect stored duct board from water damage, construction damage and other abuse.
  • If stored outside, proper protection from weather conditions should be provided.


  • Duct shall be fabricated and installed in strict accordance with NAIMA’s “Fibrous Glass Duct Construction Standard,” “Residential Standard,” “1½" Fabrication Manual” or Knauf Insulation “Air Duct Fabrication Manual” in accordance with the conditions of UL 181 listing. Duct systems shall have all transverse joints, longitudinal seams and duct wall penetrations sealed using 3" (76 mm) wide glass fabric and mastic, 2" (51 mm) minimum width heat sealable tape or 2" (51 mm) minimum width pressure sensitive tape with acrylic adhesive. Rubber-based adhesives are not approved.
  • Only UL 181-A listed and labeled products shall be used for closure systems. A listing of specific approved closure products is available from your local Knauf Insulation sales representative.
    • PRESSURE SENSITIVE TAPES: Only those tapes listed under and imprinted with designation UL 181-A-P and registered with UL.
    • HEAT SEALABLE TAPES: Only those tapes listed under and imprinted with the designation UL 181 A-H and registered with UL.
    • MASTICS: Mastic systems listed and registered with UL and carrying the designation UL 181 A-M used in conjunction with a 3" (76 mm) wide glass fabric.



  • All longitudinal and circumferential joints must be stapled with outward flaring, ½" (13 mm) minimum length staples 2" (51 mm) on centers.
  • If necessary, follow the recommendations of the tape manufacturer for cleaning the surface to be taped.
  • Center tape over staple flap and rub tape firmly in place immediately after application, using a plastic “squeegee” or similar tool, until the scrim reinforcement of the duct board facing can be clearly seen through the tape.
  • A heat-sealing iron must be used to assure a good bond when installed below 50°F (10°C).
  • Tape should not be applied to surface of duct board when temperature is below 32°F (0°C) due to the possibility of entrapping ice crystals which, upon melting, will cause tape to loosen. Heat duct board facing surface first to drive off moisture.


  • All longitudinal and circumferential joints must be stapled with outward flaring, ½" (13 mm) minimum length staples 2" (51 mm) on centers.
  • If necessary, follow the recommendations of the tape manufacturer for cleaning the surface to be taped.
  • Center tape over staple flap and seal down tape end with 500°F (260°C) iron. Do not use heat gun; both heat and pressure are required to effect a seal.
  • Press down entire length of tape with iron using a smearing action to get a good bond. Be sure edges are sealed.
  • Staples may be omitted when an automatic closure machine such as the Glassmaster Closemaster is used. In this case, iron temperature must be set at 650°F (343°C) minimum. Continuous production may require periodic pauses to allow sealing iron temperature to recover to the 650°F (343°C) minimum.
  • Allow joint to cool before stressing.


  • All longitudinal and circumferential joints must be stapled with outward flaring, ½" (13 mm) minimum length staples 2" (51 mm) on centers.
  • Brush approved mastic onto joint and embed 3" (76 mm) wide glass fabric in mastic.
  • Brush second coat of mastic over glass fabric until mesh is completely filled.
  • Follow mastic manufacturer’s instructions on curing the mastic prior to subjecting the joint to stress.


If the closure system used is not one of the approved systems described above and if application is not in accordance with stated procedures, Knauf Insulation assumes no liability for duct system performance. Use of a non-UL registered and listed closure voids the UL 181 Class 1 rating as well as Knauf Insulation’s product performance warranties.


Duct sections shall be additionally reinforced where necessary, according to Knauf Insulation and NAIMA standards. Ductwork shall be supported as required on straight runs, at all turns and at transitions to maintain proper alignment. Hangers and supports shall be in strict accordance with Knauf Insulation and NAIMA standards.

Glass Mineral Wool and Mold

Glass mineral wool insulation will not sustain mold growth. However, mold can grow on almost any material when it becomes wet and contaminated. Carefully inspect any insulation that has been exposed to water. If it shows any sign of mold it must be discarded. If the material is wet but shows no evidence of mold, it should be dried rapidly and thoroughly. If it shows signs of facing degradation from wetting, it should be replaced. Air handling insulation used in the air stream must be discarded if exposed to water.


When used in accordance with NAIMA’s and Knauf Insulation’s application instructions, the closure systems described herein meet UL 181 requirements, and the resulting system carries a Class 1 Air Duct rating. This information is not intended to be a design or fabrication manual. For specific details and recommendations on fabrication, reinforcement, hanging and other details, refer to the latest edition of the NAIMA “Fibrous Glass Duct Construction Standard,” “Residential Standard,” “1½" Fabrication Manual” or Knauf Insulation “Air Duct Fabrication Manual.” Application and installation procedure is at the discretion of and is the responsibility of the Design Engineer to meet specific job requirements.

The chemical and physical properties of Knauf Insulation Atmosphere Air Duct Board with ECOSE® Technology represent typical average values determined in accordance with accepted test methods. The data is subject to normal manufacturing and testing variations. The data is supplied as a technical service and is subject to change without notice. References to numerical flame spread ratings are not intended to reflect hazards presented by these or any other materials under actual fire conditions. Check with your Knauf Insulation sales representative to assure information is current.

Knauf Insulation Atmosphere Air Duct Board with ECOSE Technology products are certified for indoor air quality by The GREENGUARD Environmental Institute™, to both the GREENGUARD Certification ProgramSM and the more stringent GREENGUARD Gold Standard.