Solar energy utilization for covering the heating loads of buildings is an innovative and clean way which leads to lower electricity consumption. Passive heating systems are low-cost and simple technologies which are able to cover a great part of the space heating demand. Trombe wall is the most mature technology for capturing solar irradiation and transferring it inside the building in order to cover a part of the heating loads, especially the hours after the noon. In this study, an innovative Trombe wall with an extra window in the massive wall is suggested. This wall is compared with the conventional Trombe wall and the usual insulated wall in order to make a complete investigation. The examined walls are located in south direction, in order to maximize the impact of solar irradiation. According to the final results, the new Trombe wall is the most appropriate technology, creating warmer indoor profile than the other cases, especially the hours between noon and afternoon. The analysis in performed with the commercial software Solidworks Flow Simulation and the examined building is located in Athens, Greece. (C) 2016 Elsevier B.V. All rights reserved.