Patent ID: 7931074

Claim:
A heating heat exchanger for heating air, the heat exchanger comprising: a plurality of tubes which are arranged in parallel and through which a thermal fluid for heating air flows; a plurality of fins which are joined to the tubes and form heat transfer surfaces in contact with the air, wherein the tubes and the fins are arranged to form at least three heating parts in which the air is heated; a plurality of bypass passages each of which is provided between adjacent heating parts, through which the air passes without exchanging heat with the thermal fluid; first and second tank parts, for distributing the thermal fluid to the tubes and for collecting the thermal fluid from the tubes, which are arranged at two longitudinal ends of the tubes and extend to across an area where the bypass passages and the heating parts are provided; and a thermal insulating portion arranged at a boundary area between each bypass passage and an adjacent heating part, the thermal insulating portion extending along the bypass passage and the adjacent heating part in an air flow direction; wherein the bypass passages and the heating parts are arranged in an arrangement direction perpendicular to an air flow direction.