Abstract The study of passive ventilation aims at studying the processes of heat dissipation that occur naturally with or without the minimal use of mechanical instruments. The recovery of natural cooling techniques can be, in most cases, sufficient to restore the conditions of comfort inside buildings in our latitudes. For this reason we have pursued the goal of optimizing natural ventilation by installing a duct, which exploits the principle of the stack effect, inside a historic building in Poggio Picenze (Aq) dating from the fifteenth century. The goal is to obtain the best performance balancing environmental comfort and minimal energy consumption through the acquisition of an in-depth knowledge of the system operation.