Falling film evaporators and condensers have demonstrated a good performance in air-conditioning and refrigeration. A study of falling film evaporation and condensation models is presented in this document. Two different evaporator models and a condenser model are being developed considering a trade-off between efficiency and accuracy. These models are based on classical Newton's viscosity law and Nusselt falling film theory. Two libraries, with evaporator and condenser components, compatible with Modelica. Fluid, Modelica. Thermal and Modelica. Media have been implemented. The presented simulations have the expected behaviour. These models will be used to complete a model of a heat pump.