During wet roof cooling, which factor enhances its effectiveness?

During wet roof cooling, low humidity significantly enhances its effectiveness. This is because the principle behind wet roof cooling is evaporation, which relies on the moisture in the air being able to absorb more water vapor. When humidity levels are low, the air can hold more moisture, allowing for more efficient evaporation from the wet surface of the roof. This evaporation process cools the surface and, consequently, the air surrounding it, leading to a more effective cooling strategy.

In conditions of high humidity, the air is already saturated with moisture, which limits its ability to absorb additional water vapor and diminishes the cooling effect. Therefore, low humidity conditions create an optimal environment for wet roof cooling to effectively reduce temperatures.