The introduction of a new propulsion system for electric vehicles and therefore a completely different source of energy from the previous ones, brings with it the need for new systems for the management of these resources. The ESS (Energy Storage System) installed inside the vehicle, which stores the amount of energy needed to power the electric motor, must be kept at a constant temperature to allow proper operation, without loss of efficiency. For this purpose, a fluid conditioning system has been developed that allow to heat or cool, depending on the environmental conditions in which the vehicle is located and, at the same time, allows the temperature inside the passenger cabin to be regulated as the user desires; this system is called ACU (Active Cooling System).