杏吧原创

An Indian religious settlement built 1000 years ago had an early form of air conditioning created using natural resources and strategic design. The settlement contained Jain temples and dormitories, and was part of a small village called Artipura in what is now the southern state Karnataka in India, a region frequently affected by droughts both now and in the past.

The predominant feature of the settlement was a large granite-skirted natural reservoir storing rainwater, around which temples and dormitories were strategically built. The entire settlement was situated on a hillock, where winds blew because of the elevation.

at the Vellore Institute of Technology in India and his colleagues used satellite data to analyse wind patterns in the region and found that they blew from south-west to north-east, meaning they would have gusted over the reservoir before reaching the temple and dormitories.

The team used satellite images of the settlement along with an AI based on a watershed algorithm to determine the boundaries and the depth of the ancient reservoir. They found that as the air moved over the reservoir, it would have increased evaporation, which can help reduce heat. These winds would also have cooled as they blew over the reservoir, creating an air conditioning effect.

Temples at the site were made with granite and brick, and dormitories with limestone and brick; both types of walls had engineered air gaps. The researchers analysed the ancient bricks and found that although they were denser than modern ones, their use in this arrangement with air gaps reduced heat transmission.

鈥淭he settlers planned their living according to what nature offered them,鈥� says Ghosh. 鈥淎 large body of water, staggered buildings oriented towards the water resource and use of indigenous building [materials] with ample ventilation decreased the heat load.鈥�

鈥淭his paper adds evidence to the understanding that local natural water sources can help to mitigate heat-induced stress through evaporation,鈥� says at the University of Reading in the UK.

Sign up to Our Human Story, a free monthly newsletter on the revolution in archaeology and human evolution