In hot and dry climates, fountains of gently dripping water can be effective in cooling courtyards and providing a more comfortable outdoor environment. This is primarily due to two main cooling mechanisms: evaporative cooling and thermal mass.
Evaporative cooling: When water evaporates, it absorbs heat from its surroundings, causing the temperature to drop. In a hot and dry climate, the air has a low relative humidity, which allows for more evaporation to occur. As the water in the fountain evaporates, it takes in heat from the surrounding air, lowering the air temperature. This cooling effect is particularly pronounced in areas with good airflow, as the movement of air helps to disperse the cooler air and increase evaporation.
Thermal mass: Water has a high heat capacity, meaning it can absorb and store a large amount of heat energy without undergoing significant changes in temperature. As the water in the fountain absorbs heat from the surrounding air and surfaces, it helps to keep the courtyard temperature cooler than it would be without the water. The cool water can then release its stored heat energy slowly during the night when temperatures drop, providing a more stable and comfortable outdoor temperature over a 24-hour period.
Additionally, fountains can help create a more pleasant atmosphere in courtyards by providing a visual and auditory focal point. The sight and sound of gently dripping water can be soothing and calming, making the space more enjoyable and inviting.