Considering the low osmotic evaporation fluxes reported in the literature as well as the lack of information about the hydrodynamic aspect of this technique, a new laboratory scale OE module was developed. A series of experiments was carried out with pure water and CaCl2 solutions varying the flowrate and the concentration of the brine. The OE fluxes obtained in this work showed a significant improvement towards the results published by various authors. In spite of important concentration polarisation in the brine, the relative high fluxes can be attributed to high mass transfer coefficients achievable in the new lab-scale OE module