It’s a well-known fact that the areas around fountains and waterfalls are cooler in the summer, due to water evaporation. Water evaporation consumes a large amount of heat, which reduces the temperature of the air (evaporative cooling).
Evaporative cooling is very effective when the relative humidity is low (70% or less), and we can use devices (evaporative coolers) to produce it, but also pools, ponds and other water features.
Using Pools, Ponds, Water Bodies on Shaded Patios
Carefully located water features – close to the house and its windows - can provide very effective cooling breezes and fresh air. The most common involve pools, ponds and water bodies, on shaded patios, or in some very harsh climates, water roof ponds and roof sprinklers.
These methods require significant amounts of water, which can be a problem in the hot dry climates where they are most useful.
On the other hand, though not technically hard to implement, they are not also a ready-made solution; and they require shade to be effective, and are part of a wider system that has to be designed to draw the fresh air into the house, in order to ventilate it.
The easiest way to benefit from evaporative cooling is by using evaporative coolers.
Evaporative coolers are designed to capture and to force outdoor air through water-soaked pads, which filter and cool the air, before driving it into the house…
They are a lot cheaper than air conditioners, and consume 1/3 to 1/4 of the power of air conditioners. They can be very effective in hot dry climates.