Green Building Techniques Inspired By Insects

The air conditioning system of the Eastgate Centre in Harare, Zimbabwe, was inspired by termites’ nests. Credit David Brazier, via Wikimedia Commons

It’s been quite some time since we posted about biomimicry. Thanks as always to JoAnna Klein for this illuminating story:

What Termites Can Teach Us About Cooling Our Buildings

“We think humans are the best designers, but this is not really true,” a researcher said.

In the capital of Zimbabwe, a building called Eastgate Centre holds nearly 350,000 square-feet of office space and shops. It uses 90 percent less energy than a similar sized building next door.

What’s Eastgate Centre’s secret? Termites.

merlin_152612904_38aa91c7-eec0-456c-ae7a-09920b6f5ed5-jumbo.jpg

Three views of a termites’ nest, including from left, a photo of the nest, a tomography of the the nest’s interior and the networks of galleries and paths in it. Credit G. Theraulaz, CRCA, CBI, CNRS, Toulouse

In the 1990s, Mick Pearce, the building’s architect, took his inspiration from mounds built by fungus-farming termites he saw on a nature show. The insects created their own air conditioning systems that circulated hot and cool air between the mound and the outside.

As architects and builders seek new and improved ways to cool buildings without using more energy in a warming world, a study of another type of termite mound suggests that Mr. Pearce won’t be the last human to take design tips from these cockroach cousins.

We think humans are the best designers, but this is not really true,” said Kamaljit Singh, an engineer at Imperial College London and an author on the study, published Friday in the journal Science Advances. “We can learn from small animals.”

Dr. Singh and his colleagues used high-resolution scanning technology and computer and physical simulations to examine the microscopic structure of the external walls of African termite nests. In slabs that look solid to the naked eye, the team found a network of tiny, interconnected pores. Through principles of basic physics, these pores regulate ventilation, humidity and possibly temperature, within the mound and nest. These natural structures may offer inspiration for engineers and builders, emphasizing how comfort can be achieved through structure alone.

There are around 2,600 species of termites, and only about two dozen infest and destroy buildings. Many more are highly social builders aiming to protect their queens and ensure the survival of their colonies.

Carbon dioxide must exit so they don’t suffocate in their underground nests, and oxygen must enter. The mounds termites build above nests are the lungs that make this breathing possible.

But there are different types of mounds. Termites that farm fungus build structures with chimneys and openings that work like windows. The structures of non-farming termites, like the ones the researchers collected in Senegal and Guinea, have no apparent openings. To the naked eye, “everything looks blocked,” said Dr. Singh…

Read the whole story here.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s