In a new study in Frontiers in Materials, researchers showed how termite mounds can teach us to create comfortable interior climates for our buildings that don't have the carbon footprint of air conditioning.

"Here we show that the 'egress complex,' an intricate network of interconnected tunnels found in termite mounds, can be used to promote flows of air, heat, and moisture in novel ways in human architecture," said Dr. David Andréen, a senior lecturer at the bioDigital Matter research group of Lund University, and the study's first author.

Termites from Namibia

Andréen and co-author Dr. Rupert Soar, an associate professor at the School of Architecture, Design and the Built Environment at Nottingham Trent University, studied mounds of Macrotermes michaelseni termites from Namibia. Colonies of this species can consist of more than a million individuals. At the heart of the mounds lie the symbiotic fungus gardens, farmed by the termites for food.

The researchers focused on the egress complex: a dense, lattice-like network of tunnels, between 3mm and 5mm wide, which connects wider conduits inside with the exterior. During the rainy season (November through April) when the mound is growing, this extends over its north-facing surface, directly exposed to the midday sun. Outside this season, termite workers keep the egress tunnels blocked. The complex is thought to allow evaporation of excess moisture, while maintaining adequate ventilation. But how does it work?