Paris Cools Buildings with Seine River Water

Paris is expanding a thirty-year-old district cooling system that uses water from the Seine River to cool thousands of buildings without relying on traditional air conditioning. Fraîcheur de Paris operates 120 kilometers of underground pipes. Cold water is drawn from the Seine, circulated through buildings, and then returned to the river slightly warmer.

The system utilizes heat exchangers to transfer warmth between the river water and the water circulating in buildings, avoiding any mixing of the two. Currently, the Louvre, Grand Palais, hospitals, schools, and office districts are connected.

Paris plans to triple the network’s size by 2042, prioritizing hospitals, schools, and retirement homes. A renewed 20-year contract, valued at €2.4 billion, will fund the expansion. The city hopes this will reduce energy consumption and lessen the urban heat island effect caused by widespread AC use.