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RATP cools through adiabatic ventilation (March 2011)

Early 2011, the Parisian public transport company RATP presented a new technique in air refreshing in its metro station Bastille. Through an innovative adiabatic cooling, RATP can decrease the temperatures and obtain a real benefit on dust level in technical rooms, while saving energy. A European premiere.

Simple and ingenious
The system consists of a traditional ventilation system that evaporates water into the air, thus increasing air humidity by 20%. This will drop temperatures by 5 to 10 degrees Celsius. The water passes through paper filters and then evaporates when it gets in contact with the air. The filters block dust, thus also decreasing the amount of distributed particles in the air.

Lots of advantages
In contrast with traditional cooling systems, this ventilation doesn’t use any freezing agents, which are bad for the environment with high levels of green house gases emissions. Furthermore, RATP can prove a decrease in needed electricity by 80%. The tank containing the residue water is often leered avoiding any sanitary problem.

Many possibilities
If this experiment proves to be effective, RATP will introduce it systematically into its engineering. The technique can be combined with traditional cooling systems. It may be used in technical rooms such as data-centres or in large public rooms.

Want to know even more?
Download the technical PDF (in French) >

RATP lowers the set point temperatures (November 2010)

From January 2008 to February 2009 RATP lowered the set point temperature in its regional trains. The standard temperature in the trains was decreased from 18 degrees Celsius to 15 degrees. RATP estimates this has led to a reduction in the energy consumption of 40,000 kWh per train element per year. That’s the annual equivalent of 1720 kilo CO2 per train that won’t be released into the atmosphere.

2400 euro per train
Every month the consumption of energy was measured. A tricky business as the evaluation depended upon climatic conditions and upon the number of passengers into the train. Nevertheless, RATP estimates that the cutting of its energy consumption will save them approximately 2400 euro per train per year.

Importance of maintenance
The lowering of the set point temperature gave RATP the opportunity to replace all defective temperature sensors thus levelling all rolling equipment. This project made RATP fully aware of the importance of preventive maintenance in order to save energy.