The vapor-absorption refrigeration cycle is an old and well-established technique, particularly with ammonia/water and water/LiBr systems. New types of refrigerant-absorbent pairs are also being actively studied. Modeling the cycle performance requires thermodynamic properties, which have been largely based on empirical correlation equations fitted to a large amount of experimental data such as solubility at various temperatures, pressures, and compositions. In this report, we have demonstrated, for the first time, a thermodynamically consistent model based on the equations of state for refrigerant-absorbent mixtures. Various commonly known binary-pairs for the absorption cycle are used as examples. Cycle performances and some new insights on understanding the cycle process are shown. (c) 2004 Elsevier Ltd. All rights reserved.