We have investigated the thermodynamic properties of a simple model representing the thermal folding/unfolding transition of two-stranded coiled-coils. The transition temperature and the energy change for the process are analyzed in terms of the peptide concentration, using the standard properties and calculations involved in experimental work. The integration of the heat capacity curves provides realistic and correct results for the model, as it does the variation of the transition temperature with concentration. On the other hand, the van't Hoff analysis of the equilibrium constant for the unfolding process produces apparently odd results. They can only be rationalized through a careful analysis of the reaction stoichiometry, according to the reference state defined for the very simple model interactions, and the definition of the unfolded state. This point is extensively discussed, for its possible implications in the correct analysis of this and other simulation models.