The main aim of this intervention is the energetic rescue of a building now employed as a library. Problems connected with the differences between the windowed surface and the opaque partition were so consistent that an accurate analysis was necessary to know the behavior of the shell subjected to the effects induced by the external climate. The fixed target was to improve the energy performance of the structure, in order to guarantee the comfort, reducing energy waste by a more conscious planning, promoting the use of solar energy and -consequently - the reducing atmosphere pollution as well. So it has been thought to realize solar chimneys close to high thermic storage structures, supported by technologies using indirect evaporating cooling systems, capable of softening summer temperatures, resulted extreme by simulations. In winter-on the other side-a collector storage system allowed the contemporary working of thermal storage and heat transferring toward the bordered setting, through natural thermic circulation circuits. In order to give a dimension to the various systems, working only through natural ventilation, the TRNSYS 15 Code has been used, implemented by many sub-routines, describing the air floating process due to the start of convective natural motions. (c) 2006 Elsevier B.V. All rights reserved.