Using simple models of nonisothermal absorption for small and long times, the effect of heat release and heat drain on intensity of vapor absorption by immobile solution layer was analyzed. The models consider the case of moving and steady interface. The experimental results of water vapor absorption by immovable water solution of LiBr are presented. The temperature evolution curves are given for different levels of solution, as well as temperature and concentration profiles. Calculation data was compared with experiment. (C) 2003 Elsevier Ltd. All rights reserved.