Natures wonders: termite mound ventilation system (Introduction)

by David Turell , Sunday, September 06, 2015, 14:21 (3364 days ago) @ David Turell

Using vertical chimneys and a thin outer layer for the mound whiule utilizing temperature change over 24 hours:-http://www.sciencedaily.com/releases/2015/09/150902155635.htm-"The mounds are built around a large central "chimneys," which reach from gallery -- the underground vault where the bulk of the colony lives -- to the top of the mound. While the interior of the mound features larger, structural walls, the exterior is far thinner, with wall that, while impermeable to wind, do allow for the exchange of gases.-"During the day, Mahadevan explained, as sunlight either directly or indirectly warms the mound's outer walls, the air inside warms, causing it to rise.-"'What you get is a convection cell," Mahadevan explained. "The warm air can't move through the walls quickly enough, but it has to go somewhere, and the only possibility is for it to go down into the interior through the central chimney. At night, as the exterior cools, the airflow reverses, and it pulls the air up from the central part of the mound."-"The end result, Mahadevan said, is that while CO2 concentrations during the day can reach up to four or five percent in the center of the mound, the airflow at night pulls the gas to the exterior walls, where it can escape by diffusing through the wall. "But what's remarkable here is how the termites are using transients. The temperature outside the mound is oscillating, and they have developed a method to harness that to ventilate their mounds." Mahadevan said."