Termites show humans how to keep their cool

A termite mound in Namibia: Packed with lessons for human architects. Image: By Lothar Herzog from Kassel, Germany, via Wikimedia Commons

Scientists are studying the architectural skills developed by termites so we can keep cool, dry and well-ventilated in tall buildings without using fossil fuels.

LONDON, 2 April, 2019 − When humans were still living in caves termites were constructing tower blocks and tackling the difficult problems of keeping cool and dry in an adverse climate.

Now that humans, in a warming world, have the task of keeping skyscrapers comfortable and well-ventilated without the use of fossil fuels, scientists are turning to termites for advice. It appears that their architectural skills will help us solve our climate problems.

Termites live in colonies numbering thousands in inhospitable terrain in towers up to seven metres high. Inside the blocks is a complex social system of kings, queens, soldiers and worker ants living in a system of tunnels and passages, all self-ventilating, self-cooling and self-draining.

“There is a lot more to learn from Mother Nature when it comes to solving even the most important 21st century problems”

Using three-dimensional X-ray images, a group of engineers, biologists, chemists and mathematicians report in the journal Science Advances that they studied the mounds, as they are known, and found the secret lay in small holes or pores in the walls of the termite nests.

A network of smaller and larger pores helped an exchange of carbon dioxide from inside the nest to the outside. The ability of the pores to do this changed depending on the wind-speed outside, with the smaller pores sometimes taking over from the larger ones to keep the ventilation efficient. They worked regardless of the weather outside.

Lead author Dr Kamaljit Singh, from Imperial College London’s department of earth science & engineering,  said: “Termite nests are a unique example of architectural perfection by insects.

No mechanical aids

“The way they’re designed offers fascinating self-sustaining temperature- and ventilation-controlling properties throughout the year without using any mechanical or electronic appliances.”

The nests are usually found in hotter regions and the ones studied came from two West African countries, Senegal and Guinea. In the climate of these countries the mounds must be kept cool for the termites to survive. The pores also played a crucial role in this, the larger ones filling with air and reducing the heat entering the nest, a bit like the air in a double-glazed window can keep heat inside.

Remarkably the pores also had a role when it rained. Instead of getting blocked by rainwater and ruining the system the smaller pores, using capillary action, drained the larger ones, enabling the ventilation system to keep functioning.

Energy-efficiency too?

Dr Singh said: “Not only do these remarkable structures self-ventilate and regulate their own temperatures – they also have inbuilt drainage systems.”

The scientists say the newly found architecture within termite nests could help us improve ventilation, temperature control, and drainage systems in buildings – and hopefully make them more energy-efficient.

One co-author, Professor Pierre Degond from Imperial’s Department of Mathematics, said: “The findings greatly improve our understanding of how architectural design can help control ventilation, heat regulation, and drainage of structures – maybe even in human dwellings.

Nature knows best

“They also provide a new direction for future research, and will eventually bring us one step closer to understanding mechanisms that could be useful in designing energy-efficient self-sustaining buildings.”

Another of those involved in the project, Dr Bagus Muljadi from the University of Nottingham, said: “We know that nature holds the secrets to survival. To unlock them, we need to encourage global, interdisciplinary research.

“This study shows that there is a lot more to learn from Mother Nature when it comes to solving even the most important 21st century problems.” − Climate News Network