48% of the fleet is equipped with refrigerated ventilation (lines 1, 2, 5, 9, 11, and 14) and part of the fleet on metro line 4 (31 trains).
The rest of the fleet uses natural or forced ventilation with fans to create air movement. These systems, installed on older metro trains, are no longer considered satisfactory in the face of increasing heatwaves.
All future equipment (MF19), which will be deployed across the entire network between 2025 and 2036, will be equipped with refrigerated ventilation.
RER



93% of the fleet is equipped with refrigerated ventilation;
On the RER A line: the MI09 and MI2N trains are equipped with refrigerated ventilation;
On the RER B line: all renovated MI79 and MI84 trains (84% of the fleet) are equipped with refrigerated ventilation. The MI84 trains are being equipped with refrigerated ventilation as they are renovated.
The future equipment (MI20), which will be deployed on line B between 2027 and 2032, will also be equipped with refrigerated ventilation.
Tramway










The tram lines T1, T2, T3a, T3b, T5, T6, T7, T8, and T10 operated by the RATP for Île-de-France Mobilités are equipped with refrigerated ventilation.
Bus
The air conditioning of bus equipment has seen a significant acceleration in recent years, driven by Île-de-France Mobilités, with the gradual renewal of the RATP fleet to decarbonize it (for more information, see our article on the Bus2025 plan).
For example:
- In 2020, 5% of RATP buses were equipped with air conditioning;
- In 2022, 24% of RATP buses were air-conditioned;
- In 2023, 32% of buses are air-conditioned (1,485 buses or nearly 1/3 of the fleet);
- In 2024, 40% of buses are air-conditioned (1,861 buses or more than 1/3 of the fleet);
- By 2026, nearly 75% of buses are expected to be air-conditioned;
- By 2035, 100% of the fleet currently operated by the RATP for IDFM is expected to be equipped with air conditioning.