- Paris developed a district cooling network using chilled water distributed through underground pipes to buildings, reducing reliance on individual AC units.
- The system uses cold Seine river water to absorb heat from building water via heat exchangers, returning warmer water to the river with minimal ecological impact.
- Initiated in the 1990s by Engie, the network is now operated by Fraîcheur de Paris, with plans to triple its size by 2042 to cover more buildings across the city.
- District cooling improves energy efficiency and reduces urban heat island effects compared to traditional air conditioning, though it requires high initial investment.