Carbon Smart Attributes
A wool fiber is much different than a synthetic fiber
Wool is a natural, rapidly renewable material, whereas synthetic fibers are often chemical derived and then spun into a fiber. At the end useful life, wool can be re-used and/or recycled due to its durability, or composted, thus avoiding landfill. Most wool products on the market are devoid of glues and bonding agents, whereas synthetic fibers require two additional carbon-intensive processes: fiber creation and the subsequent melting into finished product.
Wool sequesters carbon and other chemicals
Much of the carbon in wool comes from the plants that wool sheep eat, though the amino acids in wool are also able to bond with CO2 and other harmful chemicals such as formaldehyde, nitrogen oxide and sulphur dioxide.
Wool has competitive thermal performance
Sheep wool meets or exceeds the r-value per inch measures of most other mediums. Wool batts measure r3.6 per inch and some loose fill products are measured at roughly r4.3 per inch.
Durability – moisture performance
Wool fibers manages moisture – absorbing and desorbing against ~65% relative humidity. The fiber itself has a hydrophobic (water repelling) exterior and a hydrophilic (water loving) interior. The five follicles within the fiber mean it can hold up to a third of its weight in moisture and still feel dry to the touch. This allows the insulation layer to go on insulating during and after inevitable bouts with moisture. Also, wool is a keratin and therefore does not support the growth of mold.
Durability – fire performance
Wool is self-extinguishing. It has a high nitrogen content (~14%) and therefore will not support a flame until 1100F. This means dangerous flame retardants are not necessary in wool insulation though it still conforms to Class A of the building code.
Wool is a natural sound absorber
Wool insulation is an excellent sound absorber, with a noise reduction coefficient of 0.90 to 1.15.