The aims of this work was to study the thermal behavior of a space refreshed by the system of capillary mats in the region of «Oued-Souf» located in southeast of Algeria and known for its scorching climate. The simulation of the house with living room equipped by mats capillary was developed with the TRNSYS software simulation. The comparison with the work of T. Catalina gave satisfactory results. Cooling by capillary mats made it possible to obtain indoor temperatures at least 10 ℃ lower than outdoor temperatures close to 47 ℃ and indoor temperatures without cooling, which sometimes reached 40 ℃. The study showed that water inlet temperature had more impact on the indoor temperature of the space than flow rate, noting that the water inlet temperature of 14 ℃ provided the best indoor temperatures that could be described as pleasant. This system also influences the indoor temperature of an adjacent, uncooled space and reduce its temperature.