A windcatcher is a wind-driven natural ventilation system that catches the prevailing wind to bring fresh airflow into the building and remove existing stale air. This technology recently regained attention and is increasingly being employed in buildings for passive ventilation and cooling. The combination of windcatchers and evaporative cooling has the potential to reduce the amount of energy required to ventilate and cool a greenhouse in warm and hot climates. This study examined a greenhouse incorporated with a passive downdraught evaporative cooling windcatcher (PDEC-WC) system using Computational Fluid Dynamics (CFD), validated with experimental data. Different hot ambient conditions of temperature (30–45 °C) and relative humidity (15–45%) were considered. The study explored the influence of different spray heights, layouts, cone angles and mass flow rates on indoor temperature and humidity. The average error between measurements and simulated results was 5.4% for the greenhouse model and 4.6% for the evaporative spray model. Based on the results and set conditions, the system was able to reduce the air temperature by up to 13.3 °C and to increase relative humidity by 54%. The study also assessed the influence of neighbouring structures or other greenhouses that influence the flow distribution at the ventilation openings. The study showed that the windcatcher ventilation system provided higher airflow rates as compared to cross-flow ventilation when other structures surrounded the greenhouse.

Natural ventilation is an energy-efficient way to provide fresh air and enhance indoor comfort levels. The wind-driven natural ventilation in courtyards has been investigated by many researchers, particularly the influence of the spatial configuration and environmental parameters on the ventilation and thermal comfort performance. However, previous research has mainly focused on the courtyard region instead of the indoor spaces surrounding it. Additionally, as a microclimate regulator, courtyards are rarely assessed in terms of the impact of vegetation, including its impact on energy consumption and thermal comfort. Evapotranspiration from vegetation can help lower air temperature in the surrounding environment and, therefore, its influence on the ventilation and thermal comfort in buildings with courtyards should be evaluated. The present study investigates the impact of vegetation on the aero-thermal comfort conditions in a courtyard and surrounding buildings in hot climates. Computational fluid dynamics was employed to evaluate the aero-thermal comfort conditions of the courtyard and surrounding buildings with different configurations of vegetation. The modeling was validated using previous works’ experimental data, and good agreement was observed. Thermal comfort indices were used to assess thermal performance. The study also evaluated the cover, height and planting area of vegetation in the courtyard. The results of this study can help develop tools that can assist the addition of vegetation in courtyards to maximize their effects. Future works will focus on looking at the influence of the strategies on different designs and layouts of courtyards.