install plastic "water walls", which have transparent containers in them, filled with water.

Thermal mass for cooling

If you live in a hot, desert climate (or similar), thermal mass can also be used for cooling. During the day, it absorbs heat from the air in the home, keeping the living space cooler and more comfortable. At night, the heat is released and allowed to escape through open windows. Externally-installed thermal mass is particularly important for this job.