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9 Advantages of Wool Insulation

Natural Air-Conditioner
terra lana 9 advantages airconA natural property of wool is it is always striving to stay in balance with the ever changing level of humidity within the atmosphere. When the external temperature drops and the amount of moisture in the air increases, wool absorbs this increase, at the same time releasing heat into the environment (warms up your house).


On a hot day the opposite occurs; wool gives off moisture into the air, at the same time absorbing energy, making the environment cooler (cools down your house). This is why wool is said to “breathe” as it absorbs and evaporates moisture. Inert mineral and synthetic fibres do not have this property and therefore do not act in the same way as a barrier to rapid changes in temperature and moisture. 

Naturally Better

Terra lana 9 advantages naturally betterThe crimp in wool fibres makes them stand apart from each other; as a result little pockets of still air are trapped between the fibres. In addition, most individual wool fibres have hollow spaces or ‘medulla’ which further increase its insulation performance.

These properties, combined with wool’s breathability mean wool significantly outperforms man made fibres for insulation. Testing by the Energy Research and Development Corporation, Wool Research and Development Corporation and CSIRO in Australia determined that maximum daytime temperatures can be reduced by 3°C and minimum night-time temperatures can be increased by 2°C for wool over man-made fibres.  
Naturally Healthy
Wool is a protein fibre similar in structure to human hair so even if wool fibres are ingested or inhaled they readily break down into their base proteins and cause no harm.

Terra Lana wool insulation is non-irritating to the skin and no special procedures or protective clothing are required for regular handling and installation.

Terra Lana wool insulation contains no harmful substances. It is non-irritant, non-allergenic, non-toxic and odourless. It uses pure and recycled wool that has been treated for insect resistance. Bioassay tests undertaken by AgResearch give satisfactory insect resistance to Tineola Bisselliella (common clothes moth).

The wool is blended with polyester melt bond fibre and thermally bonded to form a dimensionally stable structure. Polyester is the second most common clothing material after cotton and poses no health risks.

Terra Lana wool insulation is also naturally resistant to mould.  
Naturally Fire Resistant
With a high wool content Terra Lana natural wool insulation is a safe product to have in your home.

Sheep wool is naturally flame retardant because it has a high ignition temperature (570 -600 °C) and a high limiting oxygen index (25 -26% ). Wool contains high levels of nitrogen and sulphur so requires higher levels of oxygen in the surrounding atmosphere to accelerate combustion. The limiting concentration of oxygen required to support combustion of wool is higher than the ambient oxygen concentration in air (21%) which makes wool difficult to ignite.

Once ignited, the flame speads slowly and is easy to extinguish. This is because wool:
  • Has low heat of combustion and low heat release, meaning a slow fire spread rate
  • Has high nitrogen content (14%), therefore needs high levels of oxygen to keep burning
  • Has a relatively high moisture content
  • Does not melt or drip
  • Forms a self-insulating char that prevents further flame spread

To summarise then, Terra Lana's wool insulation will burn if it comes into direct contact with a flame, but is unlikely to ignite through heat (exposed wires, downlights, chimney flues) or help a fire to spread. Another plus is Terra Lana insulation will not emit toxic gases in a fire.

Naturally Absorbs Noise
terra lana 9 advantages absurbs noiseTerra Lana natural wool insulation absorbs noise from outside the building and within it. The sound molecules bounce between the thousands of fibres, causing them to expend their energy and lose their volume. All Terra Lana insulation reduces unwanted noise and all but one of our thermal insulation products is classified as having high sound flow resistance. For internal or inter tenancy walls see our specialised noise control insulation product Chatterblock.  


Naturally Absorbs Pollutants

Terra Lana natural wool insulation helps prevent sick building syndrome because it permanently traps substances like formaldehyde (a known carcinogen), nitrogen dioxide and sulphur dioxide.

Formaldehyde is commonly used in resin-based wood products, such as chipboard, and is also found in finishes, furnishings and floor coverings. Formaldehyde is slowly released from these products as the resin hydrolyses. The emissions increase with temperature and humidity. Wool molecules bind with the formaldehyde molcules in such a way that the result is irreversible and reemission does not occur. Thus wool is able to effectively and permanently remove formaldehyde from indoor air. Terra Lana natural wool insulation is capable of absorbing close to 100% of the formaldehyde commonly found in most new buildings.

Sulphur dioxide and nitrogen dioxide are by-products of combustion processes using petroleum products and coal, and are produced by gas cookers, open fires and vehicle exhausts. Wool is able to trap these harmful gases in the same way, thereby filtering your breathable air.

Terra Lana natural wool insulation contains no permethrin, pyrethroids or formaldehyde.  
Naturally Durable
The wool fibre is a complex structure, with a natural crimp and resilience, or “springiness” that allows it to be stretched as much as one third and then spring back into place. It also possesses tiny outer scales which prevent the fibres sliding past each other. These two unique characteristics assist Terra Lana natural wool insulation to maintain its loft (height) and therefore its ability to entrap air.  Terra Lana natural wool insulation will last as long as your house.

Environmentally Friendly
The wool in Terra Lana natural wool insulation is either low grade virgin wool or recycled pre-consumer wool from the textile and carpet industries (in both cases a renewable and sustainable resource). Sheep wool is completely biodegradable and can be composted without causing harm to the environment. The melt bond fibre required to hold the insulation together in Terra Lana is polyester and this also decomposes safely without emitting toxic substances. 



Low Embodied Energy
Terra Lana natural wool insulation has low embodied energy (the amount of energy required through out the whole manufacturing process). It has 7 times less embodied energy than fibreglass insulation and 3 times less embodied energy than polyester insulation. This means lower energy use in manufacturing and therefore less greenhouse gas produced by energy companies burning fossil fuels.  



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Phone. (03) 384 9001
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Green Dog House,
Unit 1, 36 Tanya St, Bromley, Christchurch