The fennec fox has adapted extremely well to survive in the high and low temperature extremes of the Sahara desert. When considering applications for biomimetic design, the fennec fox offers insight on two important functions for thermoregulation: non-evaporative cooling, and thermal lag. The fennec fox achieves non-evaporative cooling by pumping heated blood to its large ears, where a dense system of capillaries brings blood close to the skin surface to create a heat exchange before pumping the blood back to the fox’s core. Architecture ally, this biological adaptation translates into a hybrid system for passive cooling that integrates a trombe wall, a solar chimney, and earthen air tubes. This system harnesses the extreme heat of the desert sun, focusing solar gains within the upper cavity of the solar chimney. This stratum of heated air creates a stacking effect that pulls air through the earthen tube, where a heat exchange cools the air before it reaches the interior dwelling spaces. Similar to how the fennec fox maximizes the surface area of its ears, the solar chimney maximizes its surface area that is available to sun exposure, allowing for a consistent pull of air independent of outside wind speeds.
Thermal lag plays an important role for the fennec fox when it makes its retreat into the underground burrows. Here the fennec fox takes advantage of stable underground temperatures that do not experience the same extreme temperature swings at the surface level. During the day, the fennec fox uses its burrows to retreat from the harsh desert sun, taking advantage of cooler underground temperatures to effectively dissipate excess body heat. Architecturally, this behavioral adaptation translates into a dwelling that encourages migration between spaces used during the day and spaces used during the night.