RATP installed a new cooling unit in its main office building to cool the server rooms and to preheat the building in winter through the recovery of the heat produced by the cooling unit. This cooling unit allowed RATP to stop the supply of ice water, which was costly and energy-consuming.The real savings have been calculated by using the IPMVP protocol, which defines the methodology for calculating the energy use before and after the implementation of an energy-saving investment. In this case, the energy savings are based on the following calculation:
Energy savings for not supplying ice water
+ Energy savings from heating recovery
– Energy consumption of the cooling unit
Measurements of energy consumption were taken before and after the implementation and then compared. The project showed an energy use reduction of around 24%. Financial savings correspond to the volume of ice water that is no longer supplied plus the savings in terms of heating minus the energy costs of the cooling unit. They amount around €100,000 for one winter period.Investment sheet: RATP Cooling Office Building