“Air des Carrières“ (air from the quarries) is the name of the project that aims to alleviate the summer heat in the city at certain points

One of the peculiarities of Paris is the numerous vaults under the city, some of them large, connected by an extensive system of passages. Some of the passages’ ceilings run close to the street, and all of them have a constant interior temperature of 14 degrees, regardless of the weather above ground. Citizens and tourists, however, often experience the entire city as a heat island with sweltering temperatures in the summer. So couldn’t we tap into the cold underground and implement some kind of cooling in the streets and squares?

No sooner thought than done. “Air des Carrières“ (air from the quarries) is the name of the project. It is a bench made of Pierre de Bourgogne limestone. It is composed of individual elements.

The cool air is brought up from underground by blowers and blown out of the “climate bench“ through slits.

Mind you, that is: it is only a ventilation that gives people some relief selectively, not an air conditioning system that is supposed to lower the temperatures in general.

The prototype was installed on Place Jeanne d’Arc in the 13th arrondissement. The concept is by Emma Lelong (designer and scenographer), Rémi Nguyen (designer), Frédéric Blaise and Guillaume Duranel (architects at Studio Alt), Julia Lenoir (architect and urbanist). The idea was born as part of a call for proposals from the Faire project, which is looking for innovative design ideas. Support came from the Pavillon de l’Arsenal and the city of Paris, as the French magazine Pierre Actual reports.

Various companies were involved in the realization, clarifying the issues of electrics, metal and air conditioning. The natural stone was supplied by the company Rocamat.

On the one hand, the stone gives the elements of the air-conditioning bench the necessary mass to be stable, and on the other hand, it gives the seating areas a refreshing coolness.

If the cool air from the depths were only blown with fans, such a system would be broken by vandalism or people might get hurt.

Technically, the process has been in use elsewhere for a long time. In the so-called Provençal or Canadian well (puits provançal, puits canadien), the air from a house is pumped through a system of pipes underground. Usually, even without large cavities, temperatures in the ground are constant and range between 10 and 15 degrees.

The cavities under Paris, partly famous as the site of the catacombs, are due to a geological peculiarity: under the city, the building materials for the settlement lie above. Already in Roman times, limestone for the masonry of the buildings was extracted partly in underground quarries, partly at that time still in front of the gates of the city. Chalk was also extracted in large quantities and used to make gypsum.

In the following centuries, the settlement grew beyond the previous surrounding area. The underground pits were often filled in only in a makeshift manner.

In December 1774, an adit collapsed under what is now Avenue Denfert-Rochereau, sweeping away houses and people. Louis XVI commissioned the architect Axel Guillaumot to map and secure the passages and caves.

Today, there is a separate authority for the management of the underground, the Inspection Générale des Carrières de Paris. It looks after homeowners and citizens when the ground has once again started to move. One of its services is a collection of 454 maps at a scale of 1:1000 documenting the former quarries in Paris and the surrounding area. The initiators of “Air des Carrières“ naturally had to obtain the approval of the authorities for their project.

A final investigation has shown that the „climate bench“ meets its goals and is suitable for the harsh city life. The Studio can be downloaded in French. The initiators are looking for partners to continue the project, including abroad.

Download the study: Emma Lelong (Mail)

Agence Alt (French)

Inspection Générale des Carrières de Paris (French)

Brochure of the Inspection Générale des Carrières de Paris (French)

Fotos: privat

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(18.09.2023, USA: 09.18.2023)