Desert cooler increases humidity in a room. True or False — and why?

Understanding the difference between desert cooler and AC humidity effects is critical. Desert cooler does NOT reduce humidity like an AC. An air conditioner reduces humidity by condensing moisture on cold evaporator coils. A desert cooler works by the completely opposite principle of evaporating water INTO the air which INCREASES humidity. Desert cooler works on evaporation principle: hot dry air is passed through water-soaked pads. Water evaporates from the pads absorbing latent heat of vaporization from the air thus cooling it. The evaporated water becomes water vapor and mixes with the room air INCREASING its humidity. This is why desert coolers are effective only in DRY HOT climates (like Rajasthan) but ineffective in humid climates (like Mumbai) because humid air is already near saturation and further addition of water vapor does not cause effective evaporation. Desert cooler adds water vapor it does not remove it. Desert cooler uses no refrigerant at all. It uses only water and air. The cooling mechanism is purely evaporative (phase change of water) not a refrigeration cycle.