A surface coating layer, in contact with a surface of a base material of a heat exchanger, comprises a plurality of composite layers comprising a first layer contacting a surface of the base material, the first layer comprising a first matrix and a first nanobody, and a second layer contacting a surface of the first layer and having an interface with the air, where the first layer and the second layer each include a different amount by volume of the first nanobody and the second nanobody, respectively.