Heater element for heating vehicle cabin, heater unit, heater system, and heater element for purifying vehicle cabin

A heater element for purifying a vehicle cabin, comprising:

• a honeycomb structure comprising:
• an outer peripheral wall;
• and partition walls disposed on an inner side of the outer peripheral wall, the partition walls defining a plurality of cells each forming a flow path from a first end face to a second end face, the outer peripheral wall and the partition walls comprising a material having a PTC property;
• a pair of electrode layers provided on a surface of the outer peripheral wall;
• and
• a functional material-containing layer provided on surfaces of the partition walls,
• wherein the honeycomb structure has a shape having a long axis and a short axis in a cross section orthogonal to a central axis,
• wherein the pair of electrode layers are formed in a band shape extending parallel to the central axis, and are arranged on the surface of the outer peripheral wall so as to face each other across the long axis passing through a center of gravity of the honeycomb structure in the cross section orthogonal to the central axis, and
• wherein the heater element further comprises a plate-shaped external connecting member disposed on an end portion side of each of the electrode layers, the plate-shaped external connecting member being in plane contact with each of the electrode layers.