A model for the global dynamics of a sorption heat pump is presented in this work. It involves a model of a reactor where gas-solid reaction takes place coupled with a model of a two-phase closed thermosyphon cooling exchanger. Simulations of the whole discontinuous cold production process have been performed. The good agreement between experimental and simulation data shows the ability of the present model to accurately represent the dynamics of such systems. An analysis of the physical mechanisms governing the dynamics of each process stage is made. It was shown that mass limitation strongly slowed down the synthesis when the other phases of the process are mainly dependent on the thermal behavior of the transformer. This model can be used as a powerful tool for the optimization of sorption systems and for the intensification of such processes. (c) 2005 Elsevier Ltd. All rights reserved.