The life span of an evaporative cooling system depends on a variety of factors, including the quality of the system, the environment in which it is installed, and the amount of maintenance it receives. Generally, evaporative cooling systems can last anywhere from 10 to 20 years. However, with proper maintenance and regular servicing, the life span of an evaporative cooling system can be extended significantly. Regular maintenance should include cleaning the evaporator coils, replacing the filter, and checking the water level in the reservoir. Additionally, it is important to ensure that the system is not exposed to extreme temperatures or humidity levels, as this can reduce its life span.