In the present study, the effect of MWCNT/Fe coatings on steel substrate was investigated using R134a vapor. Specifically, CNT and $Fe_2O_3$ powder were used as components in mechanically alloyed powder composites, which were used to fabricate surface coatings. There were two types of coatings used in the tests. The first one was pure Fe coating and the second one was the MWCNT/Fe composite coating. The powders were coated on a plain carbon steel plate by electrostatic spraying. This was followed by sintering at $900^{circ}C$. Results showed that the condensation heat transfer can be enhanced by MWCNT/Fe composite coatings, while a pure Fe coating can diminish the enhancement in comparison to the plain carbon steel plate.