This paper addresses the thermal performances of a zeolite-based open sorption heat storage system to provide thermal energy for space heating needs. The study focuses on the experimentation of a significant scale prototype using zeolite 13X/H2O as the reactive pair, and on the development of a 1D mathematical model used to predict both the charging (desorption) and the discharging (adsorption) processes occurring inside the storage unit. The experimental campaigns and the numerical results lead to some promising conclusions on the thermal performances of such a storage unit. With 40 kg of zeolite, a temperature lift of 38 degrees C on average at the outlet of each zeolite's vessel during 8 h was achieved during the discharging with an airflow inlet at 20 degrees C, 10 g/kg of dry air of specific humidity and a flow rate of 180 m(3)/h. Some discrepancies between the experimental and simulation results were observed during both the charging and discharging tests, and were explained. (C) 2015 Elsevier Ltd. All rights reserved.