How the Seine River Keeps the Louvre Cool During the Summer

As Paris braces for a heatwave this weekend, a little-known network of underground pipes will cool the Louvre museum and other historic monuments using water from the River Seine.

Since 1991, river water has been used to cool more than 800 buildings through a humble but efficient system that is still relatively little used around the world.

The City of Light has the largest urban cooling network in Europe: 110 kilometers of underground pipes, which help reduce the use of energy-hungry air conditioning systems.

“It’s like in ‘Batman’!” exclaims a pedestrian in Paris’s posh and touristy eighth arrondissement, as a spiral staircase leading to an underground cooling network emerges from the ground.

The technology is not new. The United Nations headquarters in New York has been using water from the East River for cooling since the 1950s.

But it takes a lot of planning and construction, so these efficient and sustainable cooling systems are still relatively uncommon.

In Paris, however, the network has grown considerably in recent years to cope with more intense and frequent heat waves. The first of the summer (north) is expected as early as this coming weekend.

The process works in a similar way to a district heating network, but in reverse: heat is transferred from the air to cold water that is pumped through pipes to city buildings.

But unlike conventional air conditioning, it does not release hot air into the streets, according to Fraîcheur de Paris, which manages the Seine cooling network and others in Barcelona, ​​Singapore and Dubai.

The company, co-owned by French energy company Engie, says it also offers significant savings on electricity consumption, chemical use and carbon dioxide emissions.

Heatwaves could raise summer temperatures to 50°C by 2050 in Paris, says Raphaëlle Nayral, general secretary of Fraîcheur de Paris.

For Nayral, the city needs a more sustainable solution than air conditioning, which carries with it a high demand for heat and energy. “Otherwise, we will make this city completely uninhabitable,” he says.

Studies have shown that extensive use of air conditioning systems can increase heat in urban centers by up to 0.5ºC, a value that increases as more units are installed.

This type of air conditioning also accounts for 7% of global greenhouse gas emissions, the UN estimates. This is partly due to energy use and refrigerant gases that tend to leak.

In the Paris network, 12 cooling stations pump chilled water from the Seine to 867 locations across the city, including the National Assembly building, where deputies debate laws.

Even in winter, the river can be useful for cooling server rooms and shopping malls.

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