EcoFill™ Wx Blowing Wool Insulation

EcoFill™ Wx Blowing Wool Insulation

Knauf Insulation EcoFill™ Wx Blowing Wool Insulation is an unbonded, virgin fibrous glass blowing insulation having a high degree of post-consumer recycled content, designed for weatherizing and retrofitting existing housing.


EcoFill™ Wx Blowing Wool Insulation is used to dense-pack sidewalls using the drill and fill technique common in retrofitting homes or in home weatherization activities. EcoFill Wx is also excellent for doing open blows in attics. This means that only one product is needed to complete an insulation retrofit/weatherization project.

Features and Benefits:

  • Fills all gaps and voids in wall cavities, creating a thermal barrier against outside air and better temperature control.
  • Has greater resistance to air infiltration than cellulosic materials.
  • Resists heatflow with an R-value of R-15 in 2 X 4 construction.
  • Resists heatflow with an R-value of R-23 in 2 X 6 construction.
  • Absolutely will not settle in walls.

And Attics:

  • Will not change from its intended R-value over its lifetime.

Saves Warehouse Space:

  • EcoFill Wx requires about one-half of the warehouse space of competing cellulosic products.
  • Twice as many jobs can be loaded on a truck when EcoFill Wx is used instead of cellulosic products.

Better Coverage than Cellulose:

  • More than 2x the coverage per bag.


  • Over 61.9% post-consumer recycled content.
  • Each bag contains the equivalent of 30 recycled bottles.

Improves Crew Productivity:

  • With EcoFill Wx, installers spend less time handling bags.
  • In a 2000 square foot home, about 46 bags ofEcoFill Wx are required, compared to 145 bags of cellulosic material.
  • Installs cleaner than cellulose, virtually dust-free. Blows clean and smooth and does not require stabilizing.

Strong Poly Bag Packaging:

  • EcoFill Wx is packaged in a very strong poly bag that prevents bag breakage and jobsite spillage.
  • The bags stack well and have a coefficient of friction sufficient to reduce slippage.

Indoor Air Quality:

  • GREENGUARD™ Gold Certified to meet the toughest indoor air quality standards in the industry.


  • Glass mineral wool is naturally non-combustible and remains so for the life of the product. Unlike cellulose EcoFill Wx requires no additional fireretardant chemical treatments. Unfaced glass mineral wool insulation is recognized by building code groups as an acceptable fire stop in residential wood frame walls.

Resists Microbial Growth:

  • Does not promote the growth of fungi or bacteria.
  • Will not rot or sustain vermin, rodents or insects.

Specification Compliance:

  • ASTM C 764; Type I
  • HH-I-1030B; Class B
  • Greenguard Indoor Air Quality Certified®
  • GREENGUARD Gold Certified
  • Knauf EcoFill Wx glass mineral wool blowing insulation is manufactured with a minimum of 40% post consumer recycled glass.
  • Meets the Quality Standards of the State of California.

Technical Data

Air Infiltration Resistance:

  • When tested against three cellulose products using ASTM C 522, EcoFill Wx showed 20 to 100% better air flow resistance than three leading brands.

Noise Reduction:

  • Improves Sound Transmission Class (STC) ratings by 4 to 10 points.
  • A 3 point STC change is a noticeable improvement.

Surface Burning Characteristics:

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

Critical Radiant Flux (ASTM E 970):

  • Greater than 0.12 W/cm2.

Moisture Vapor Sorption (ASTM C 1104):

  • 5% maximum by weight.

Corrosion (ASTM C 764):

  • No greater than sterile cotton.
  • Will not accelerate corrosion of aluminum, steel or copper.

Microbial Growth (ASTM C 1338):

  • Does not support microbial growth.

Non-Combustibility (ASTM E 136):

  • No temperature rise above 54º F (30º C).

Thermal Performance:

The stated thermal performance of EcoFill Wx Blowing Insulation requires installation in accordance with the manufacturer’s instructions. Failure to install the material properly will impact the performance of this product.

Equipment Required:

To achieve labeled R-value, this product must be applied with a pneumatic blowing machine and a corrugated hose with a minimum ¼” internal corrugation, a minimum length of 150’. Coils in the hose should not be less than 36” in diameter. Acceptable material feed rate is 5-35 lbs./minute. The recommended feed rate is 15-35 lbs./minute.

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.


The chemical and physical properties of Knauf EcoFill Wx Blowing Insulation represent typical average values determined in accordance with accepted test methods. The data is subject to normal manufacturing 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.