Evaluation of old building processes in the housing of Algeria’s arid regions and its improvement by integration of passive downdraught evaporative cooling

•Identification of thermal discomfort in the traditional house of In Saleh by an experimental study.•The adaptation of a passive downdraught evaporative cooling system allows improving the comfort in the habitat of In Saleh during the overheating period.•the decrease of the wind catcher area as well as the increase of the water flow used allows improving the performance of the system and its climatic adaptation to the region of In Saleh. The objective of this study is the thermal evaluation and improvement of summer comfort of a dwelling in the arid climate of the In Saleh region in southern Algeria. An experimental study was conducted to assess the impact of old constructive processes on summer thermal comfort. The experimental tests have shown that a diurnal temperature difference of 8 °C can be reached during the overheating periods. Moreover, summer comfort is not achieved, the need to adapt a passive cooling system is very necessary. This study also aims to improve the hygrothermal comfort of the dwelling under study by adapting passive downdraught cooling system with water spraying to the climatic conditions of the arid region of In Saleh. to this end a theoretical parametric approach was performed using a mathematical model reported in the literature to adapt the passive downdraught cooling system to the climatic context of our region. The results show that a temperature difference of 15 °C and a humidity level of 50 % can be attained during overheating periods. These results confirm that this system can be an adequate solution in the different arid regions of southern Algeria.