Evaporative coolers (also called swamp, desert, or air coolers) are devices that cool air through the simple evaporation of water. They differ from refrigeration or absorptionn air conditioning, which use the vapor-compression or absorption refrigeration cycles.In moderate humidity locations there are many cost-effective uses for evaporative cooling, in addition to their widespread use in dry climates.
For example, industrial plants, commercial kitchens, laundries, dry cleaners, greenhouses, spot cooling (loading docks, warehouses, factories, construction sites, athletic events, workshops, garages, and kennels) and confinement farming (poultry ranches, hog, and dairy) all often employ evaporative cooling.
In highly humid climates, evaporative cooling may have little thermal comfort benefit beyond the increased ventilation and air movement it provides.
As you can see in the photo, that is a medium size Evaporative Air-cooler (or Ventilation Fan) suitable for shop lots or outdoor events.
