Sustainable air conditioning inspired by termites

Tomorrow’s climate-smart buildings could be inspired by termites, thanks to research from Lund University in Sweden.

Termite mounds have a sophisticated ventilation system that enables air circulation throughout the structure, helping maintain and regulate temperature and humidity.

The research showed that by imitating the system used by termites, an energy-efficient air-conditioning system for buildings could be created.

“The digitalisation of design and construction processes creates enormous opportunities for how we shape architecture, and natural and biological systems provide an important model for how we can best utilise these possibilities,” said David Andréen, senior lecturer at the Department of Architecture and Built Environment at Lund University, who wrote an article published in the journal Frontiers in Materials.

The study focused on the interior of termite mounds, which consist of thousands of interconnected channels, tunnels and air chambers and how these capture wind energy to exchange oxygen and carbon dioxide with the surroundings. It explored how the systems work and how similar structures could be integrated in the walls of buildings.

The idea is to create new ways to control the airflow in buildings that will be more energy-efficient than traditional air conditioning, which uses the bulk flow principle, normally driven by fans.

Instead, it is possible to develop systems that are turbulent, dynamic and variable. “These can be controlled by very small equipment and require minor energy provision,” Andréen said.

In the study, the researchers demonstrated how airflows interact with geometry — the parameters in the structure that cause the flows to arise and how they can be selectively regulated. These can be driven without using mechanical components such as fans, valves and similar, as only electronic control is required. 

“This a precondition for a distributed system in which many small sensors and regulating devices are placed in the climate-adaptive building envelope through miniaturisation, durability/sustainability and cost reduction,” Andréen said.

This enables regulation of the building’s indoor climate and the control of factors such as temperature and humidity without relying on large fans and heating and air-conditioning systems. The mechanisms are dependent on being able to create complex internal geometries (on the millimetre to centimetre scale), which is only possible using 3D printing. Through 3D printing, value can be added to the built environment to create sustainable architecture that otherwise would not have been possible.

“It’s fascinating how the termites’ building process manages to create extremely complex well-functioning “engineering masterpieces”, without having the centralised control or drawings to refer to that we would need,” Andréen said.

Image credit: iStock.com/jeridu