For example, the warmth of sunrays makes its way to Earth despite the vast distance between them. Thermal convection is manifested in boiling water, where hot water moves up and cooler water flows down.
Finally, thermal conduction depends on direct contact between bodies. For example, when you touch a glass cup containing hot liquid, you instantly feel the heat; yet, if the cup is metal, the experienced heat will be stronger. In conclusion, different substances are either good or bad conductors of heat.
Clothes are bad conductors of heat. As such, they keep the air surrounding the body warm and prevent the loss of body heat. Consequently, we do not feel cold.
It is worth mentioning that the number of pieces we wear is more significant than their thickness. Our skin is cooled primarily by convection currents in the air. Clothing, especially wool, traps air in small pockets, which reduces or eliminates convection. There can still be conductive cooling through the cloth, but cloth is a good insulator.
Home insulation, like styrofoam panels, fibreglass or blown-in cellulose act like clothing in reducing heat transmission by convection. Home insulation is rated by its R value of resistance to energy transfer.
Air pockets within snow and ice function as excellent insulators. Many small mammals build snow dens to keep themselves warm, thereby taking advantage of the insulating properties of the snow. The price you pay for all of this is that wool does take slightly longer to dry than other fabrics. Even if you do get completely soaked through, it will still breath and keep you warm. In fact, science has yet to produce a fibre with so many unique qualities. All from the humble sheep. There really is something to be said for sticking to the fibres nature has given us.
Using felted wool he devised the world famous Swanndri bushshirt. Proof that time and technology have not forgotten tried and true wool for warmth. What we do best is take that natural knowhow and add our own to create comfortable, practical garments that last. You take the only other fibre on the planet known to have the same characteristic as polar bear fur, and blend it together.
What kind of fibre would give you the same properties of a polar bear fur? That would be the pesky common brushtail possum. New Zealand's very own seriously invasive pest. The pest that is killing ecosystems.
The possum is listed as a major agricultural and conservation pest in New Zealand. While this little blighter may look cute, they carry bovine TB which is the major agricultural threat. They also eat the plants nectar and berries that the native birds need to survive. We use the fur fibres of the possum to make wool even better.
Possum fur will not freeze, even when exposed to periods of prolonged cold. It is also incredibly soft, hugging the skin without itching or irritating it in any way. Combine lovely merino and silky possum, and you have a sustainable and environmentally beneficial super garment!
One that feels lovely on, looks great for ages, and has properties that science has not been able to replicate. Luxurious base layers , sat next to your skin all day.
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