Measurements have been made of the deposition rates of water droplets, typically 20 mu m in diameter, from an air stream. A number of mass transfer processes can be postulated, including condensation and the turbulent deposition of particles, but in addition we can estimate the influence of thermophoresis and diffusiophoresis on the movement of droplets through boundary layers. We first show rates of particle transport under adiabatic conditions, in which turbulence mechanisms prevail. These are at the upper limit of the wide range of results reported in the previous literature. We believe turbulence may well have been enhanced due to distortions in the test-section shape, necessary for the installation of instrumentation. Deposition rates are increased significantly in the presence of condensation. A phenomenological model, accounting for the influence of thermo- and diffusiophoresis, underpredicts the additional particle deposition. Given observations of dropwise condensation, the associated roughening of the walls is thought to be responsible for the discrepancy, and is identified as an area for further development.