Abstract: The paper reviews progress in dropwise condensation research from 1930 to the present. An experimental investigation has been performed in which promotion of dropwise condensation of water vapors is achieved by coating a bare iron tube with polytetyrafluoroethylene (Teflon). Experimental Overall heat transfer coefficients are presented for the dropwise condensation of water vapors on the Teflon coated tube and for filmwise condensation on the bare iron tube. The overall heat transfer coefficients obtained for dropwise condensation on Teflon coated tube is approximately 20 to 60 percent more for water than those for filmwise condensation on bare tube.

Keywords: Dropwise condensation, filmwise condensation, Teflon, Overall heat transfer coefficient.