## 4 Discussion  
The results highlight significant reductions in internal air temperatures due to natural ventilation. This finding aligns with Edition [64], which states that temperature control by natural ventilation is often the only means of providing a level of cooling when mechanical air conditioning is unavailable. The issue is exacerbated in densely populated urban centers, where tall buildings can obstruct wind flow. While obstacles like buildings can reduce cooling energy needs by providing shade, they may also limit wind action in the summer, undermining the effectiveness of natural ventilation, the most important cooling solution. Therefore, among potential obstacles, investing in trees is more advisable. Trees provide shade and mitigate urban heat island effects, benefiting entire neighborhoods. As illustrated by VOX [65], vegetative cover in a city can significantly impact thermal comfort compared to concrete-dominated areas. Trees also reduce stress and health problems related to heat, decrease energy needs, and help retain water [65]. Green roofs offer similar benefits but may increase water usage. Furthermore, considerations regarding regional air quality must be taken into account when evaluating the feasibility of natural ventilation as a passive cooling strategy. For example, in Teresina, where natural ventilation has shown a considerable impact on reducing indoor air temperatures, annual air quality is moderate. This limitation may restrict the effective use of natural ventilation throughout the year, potentially compromising indoor thermal conditions. Similarly, in Sanlurfa, air quality poses additional challenges. Particles from nearby deserts could hinder the use of natural ventilation, especially during periods of high pollution, as prolonged exposure to outdoor air could negatively impact indoor air quality and occupant health. These findings indicate that while natural ventilation can be a highly effective passive cooling strategy, its implementation must be tailored to the specific environmental and air quality conditions of each region. High-pollution areas may require supplementary or alternative cooling strategies to maintain both thermal comfort and indoor air quality standards, ensuring the health and well-being of occupants. The results also show that all proposed improvements effectively reduce air temperatures and energy needs, enhancing the thermal environment of occupants. Thermal insulation, when combined with natural ventilation, significantly reduces air temperatures, a benefit not observed without ventilation. The proposed passive design solutions demonstrated positive outcomes across all three study locations, indicating their versatility and effectiveness in diverse hot climates. Implementing measures such as optimized shading, insulation, glazing adjustments, and controlled natural ventilation proved beneficial in reducing the need for active cooling systems. In scenarios where active systems might otherwise be required to achieve the thermal environment, these passive strategies significantly reduced potential energy consumption,  
Figure 15: Effect of combined passive solutions on energy needs and indoor air temperature for house with inclined roof and gypsum board of Sanlurfa, Turkey. (**a**) Annual energy. (**b**) Annual indoor air temperature distribution. undersoring their value in energy savings. By decreasing reliance on air conditioning or heating systems, these interventions not only enhance the thermal environment but also contribute to sustainability goals, highlighting their efficiency for broader application in similar climatic conditions. Despite improvements in all cooling indicators, many hours remain outside the defined comfort zones, especially for Teresina. Although the acceptable thermal comfort range for naturally ventilated buildings is significantly broader than for buildings with standard mechanical HVAC systems [66], it would be beneficial to design systems that passively enhance natural ventilation to further improve the thermal environment.