Fur as Insulator
When comparing humans and polar bears on an infrared camera the differences are hard to miss. Even with the humans decked out in well-designed cold weather gear, polar bears are able to retain much more body heat. Even when temperatures fall well below 0, polar bear fur lets out an incredibly low amount heat. In the world of insulation, it seems that you can’t get much better than polar bear fur.
In 2014, researchers from the University of Namur in Belgium published a paper challenging the understanding of how such fur is able to retain heat so well. It was previously thought that air pockets withing the fur are what slowed the escape of heat. Insulation through conduction. The research challenges this theory, suggesting that radiation plays a much more important role.
They propose that each individual strand of fur acts as a “radiant shield”, absorbing a portion of the body heat from within. Once absorbed, the fur radiates some of the heat outward and some of the heat back towards the source. The heat is decreased and radiated back inward as it travels through the layers of fur. The effect is called “backscattering”. Researchers found that 1″ of material that uses this backscattering technique may be as efficient as several inches of contemporary insulation used on buildings today. The research remains theoretical at this point as prototypes have yet to be tested, but the possibilities seem promising. Who wouldn’t love 1″ thick super-insulation?