A lumped-parameter dynamic simulation of a single-effect LiBr-H2O absorption chiller considering the effects of thermal masses of main components is presented in this paper. The continuity of species constituting the LiBr-H2O solution, momentum equations and energy balances are solved simultaneously. Six various cases are considered to evaluate the effect of thermal masses of all and some components on the key parameters of an absorption chiller. To eliminate the numerical errors, thermodynamic properties are taken from the EES software. Since the performance of the cycle should be evaluated in each time step, a link is made between EES and MATLAB softwares. The fourth order Runge-Kutta method is selected to solve the simultaneous differential equations. The results show that the heat transfer rate of high-pressure components (generator and condenser) are highly dependent of thermal mass of the condenser whereas the heat transfer rate of low-pressure components (evaporator and absorber) are hardly affected by thermal masses. Furthermore, the major components except condenser show approximately the same behavior when thermal masses are ignored. (C) 2012 Elsevier B.V. All rights reserved.