Utilizing Natural Ventilation as a Passive Design Strategies to Enhance Energy Efficiency of Low-Income Houses in Erbil City.

Natural ventilation is a sustainable and cost-effective strategy for improving indoor environmental quality and reducing energy consumption, particularly in hot, arid climates. This study investigates the integration of natural ventilation strategies, specifically wind catchers, evaporative cooling, and façade openings, to enhance thermal conditions and energy efficiency in low-income housing in Erbil, Iraq. A mixed-methods approach was employed, including field surveys, IES-VE simulations, and statistical analysis using SPSS. Simulations were conducted under typical summer conditions as well as an extreme heat event, using local climate data and empirical wet-bulb temperature calculations to assess airflow and indoor temperature across varying building orientations, windcatcher geometry, and evaporative effectiveness levels (60%–90%). The results indicate that wetted wind catchers can reduce indoor temperatures by approximately 13.3 °C, with upper horizontal windows performing better than combined horizontal–vertical outlets. Statistical tests confirmed these effects as significant, reinforcing the potential of natural ventilation as a low-cost and sustainable cooling strategy. However, the study acknowledges certain limitations: simulations were restricted to summer and extreme heat conditions, excluding transitional and winter seasons, and evaporative performance was modeled at fixed efficiency levels, which may vary in real-world operation depending on water supply, quality, and maintenance. Overall, the findings demonstrate that combining traditional passive strategies with modern simulation tools offers a practical pathway to improving comfort and reducing energy demand in hot-climate, low-income housing.