Notoriously hot city rediscovers ancient technique to help its residents stay cool: ‘This is not an air-conditioning system’

Rick Kazmer
Mon, September 4, 2023

Thousand-year-old Persian technology could help officials in Seville, Spain, to tackle extreme overheating, if only modern-day politics can stay out of the way.

City leaders are bracing for temperatures that are expected to pass 120 degrees Fahrenheit in the coming years. In response, they are working on a project in the city’s Isla de la Cartuja that uses a “bioclimatic” effort to cool down, according to Urban Innovative Actions.

“This is not an air-conditioning system like the one you may have in your home,” Juan Luis López, an engineer and the project’s supervisor, told Bloomberg Green. “We use natural techniques and materials to reduce temperatures.”

The project, called CartujaQanat, could cost around $5 million or more, funded in part by the European Union. Some of the work is already complete, with the goal of cooling the air down for the busy city.

A Bloomberg report describes architecture that fosters breezes, fresh green spaces, and underground aqueducts that borrow from ancient civilizations. The water flow can cool the nearby environment using air, water, and solar power.

The latter tech is fascinating, yet simple. Water is brought into underground tanks at night, where it cools. During the day, solar-powered pumps send the water through pipes, which travel by fans, creating cooler air.  “Small openings in the floor and steps allow the refreshing current to seep into the square,” all per a Bloomberg description.

And while progress has been made, Bloomberg reports that a change in Spanish political leadership has placed the work in “limbo.” When Bloomberg visited the site in July, the news agency reported that it was not open to the public. There was overgrown vegetation “and piles of dried leaves.” Delayed contract bids, inflation, and other roadblocks are slowing progress as well.

However, Seville’s new mayor, José Luis Sanz, told Bloomberg that he supports the project, noting “[that the] impacts of climate change are more than obvious.”

As planet overheating continues to set records, clean ways to cool populated places without adding to air pollution are vital. This project in Seville, which borrows from the work of ancient Persians, could be a model for other cities.

“The goal is to test the technology, to learn from it, and fine-tune it so we can replicate what works elsewhere,” López told Bloomberg.