Remember that ambient temperature must be 180C or higher in order for the appliance to work. In this operation function, room temperature rises slightly. Air purification The air inside the room (ventilation) is circulated through a filtering system when the appliance is set to this function. The appliance comes with a basic filter (already fitted on the appliance) and a purifying filter (except on models PAM0520) to be fitted by the user-See “Fitting the purifying filter (double active)”- again