What is the role of evaporative cooling when implemented in rooftops or internal courtyards?

• A. Water features or mist can augment cooling, but humidity impacts effectiveness; use with ventilation.
• B. Humidity does not affect evaporative cooling.
• C. Evaporative cooling is always the best method in tropical climates.
• D. Water features or mist have no impact on cooling.

Answer: (D)

Evaporative cooling works by water absorbing heat as it changes to vapor, which cools the surrounding air. In rooftops or internal courtyards, water features or mist increase the surface area where evaporation can occur, helping to lower the local air temperature and improve comfort in these outdoor or semi-outdoor spaces. Yet the effectiveness depends on humidity: in a very humid environment, the air is closer to saturation, so evaporation slows and the cooling benefit diminishes. That’s why this cooling approach is most reliable when there’s good ventilation to remove moist air and bring in drier air, allowing continuous evaporation. Water features or mist do influence cooling, but their impact is most pronounced with proper airflow and manageable humidity.