Distributed dynamic models of a simple coaxial-type evaporator are implemented in the simulation tool Sinda/Fluint. In order to obtain data for model validation an experimental set-up is built, where dynamic responses to changes in inflow and/or outflow of refrigerant are recorded. Model validation shows that the dynamic response of the homogeneous model is too fast whereas the simulation results based on the slip-flow model agrees very well with the experimental results. Another difference in the results from the two types of models is the estimation of charge. The charge calculated by the use of the homogeneous model is approximately a factor 3 less than the charge calculated using the slip-flow model.The overall conclusion is that when one wants to investigate the dynamic behaviour due to the movement and amount of the refrigerant in the evaporator, then it is needed to use a slip-flow two-phase model as the homogenous model produce a too fast response.