In geographical zones with a continental Mediterranean climate, the convenience of passive systems becomes doubtful, when one takes into account real thermal performance throughout the different seasons of the year. It is assumed that these systems stay shut down during summer thus avoiding undesirable solar gains. This study contributes answers to some questions about this topic by means of a comparative experimental analysis on the thermal performance of three passive systems (Massive/Trombe Wall, Direct Gain and Sunspace) and two traditional constructive systems (with/without low energy measures) for various situations (with/without night/day protection and ventilation) and climatic seasons (winter, summer and one neutral-times of spring and autumn). The measured variables are solar irradiance, outdoor temperature and indoor temperature taken from different points of the physical models. The applied procedures, technics and instruments are explained and some conclusions are drawn based on the obtained results.