In the European project EasyMED an innovative, multi-effect distillation plant for seawater desalination has been developed. The basic elements of each effect are vertical plates. On one side of a plate, seawater is distributed as a falling film, whereas on the other side, the plate is heated by condensing vapour generated in the previous effect. Our Institute is concerned with the heat and mass transfer in a system based on numerical experiments. Good agreement was achieved between a one-dimensional (1D) and a two-dimensional (2D) model capturing the evaporating falling film. Being less computationally expensive and sufficient for practical requirements, a 1D model was adopted for conjugate heat transfer between condensing and evaporating cells.