Notes that evaporative cooling equipment and systems are available for residential, agricultural and industrial markets. In recent years the development of highly effective coolers has broadened the applications for evaporative cooling. Discusses the characteristics and advantages of evaporative cooling applications. Goes on to discuss factors involved the design of evaporative coolers, concerns about air quality, water quality, chemical water treatment, humidification and maintenance. Concludes that a clean water system is the most important aspect for maintaining an evaporative cooling system. Good housekeeping practices, along with recommended annual/periodic maintenance will produce a well-operating evaporative cooling system without biological, air quality or water quality problems.