What is the difference between evaporative coolers and misting systems?

Misting systems spray a shower of water into the air that will collect on people, objects, equipment and floors, no matter how fine. Portacool evaporative coolers do use water, but the process of evaporation produces cooler air without a mist. A small amount of humidity is added to the air, but with proper ventilation it is not noticeable and will not cause rust formation on equipment.