Design of finned-tube heat exchangers or coils, and in particular their refrigerant circuits, depends primarily on experimental data and the associated development cost is in general rather high. Taking into consideration the high number of possible refrigerant circuits, the input of each circuit into a particular design computational tool would be a very time-consuming operation. In the present work, we present a model to automatically generate refrigerant circuits for finned-tube heat exchangers based on a recursive algorithm. The model assumes that a tube is only connected to those that are in its neighbourhood. In this way the total number of connecting bend tubes is a minimum and, as a consequence, material usage is at its lowest level. In addition, a finned-tube heat exchanger performance simulation model is developed to evaluate the performance of a finned-tube heat exchanger with the automatically generated circuit. This simulation model can handle arbitrary refrigerant circuits and it is sufficiently user-friendly to allow the easy inclusion of new features. In addition, it can simulate coil performance by analyzing the coil into uneven length elements and by considering non-uniform air distribution at minimal computational cost. The simulation results of the model have a maximum +/- 10 % error compared with experimental data, most within +/- 5 % deviation of the experimental data. The automatically generated circuits are evaluated on the basis of the heat exchanger performance simulation results. This combined feature has the potential of being a powerful tool in designing finned-tube heat exchangers.