14. A converter comprising:a housing;
a plurality of heat generating elements disposed in the housing; and
a pipe disposed in the housing and including an inlet and an outlet,
wherein the pipe is formed in a tube shape with a constant cross-sectional area in a vertical direction from the inlet to the outlet,
wherein the housing includes a fluid channel in which the pipe is disposed,
wherein the pipe is surrounded by the fluid channel except for the inlet and the outlet, and
wherein the pipe and the housing are integrally formed by an insert injection molding method.