This filter system is used for the filtration of plasticizers using electrostatic precipitators. The polluted intake air is drawn in by a fan (Fan 1). The polluted air is mixed with fresh air before it is directed to the precipitator. The fresh air is preheated by a heat exchanger and a heater (temperature regulator). A second fan (Fan 2) is used for this purpose. The actual separation is performed by three electrostatic precipitators, each with two high-voltage units. Each high-voltage unit has two collectors and two ionizers. Each electrostatic precipitator is considered as one stage of the filter unit.