With evaporative cooling, a complete air change occurs every one-to-three minute. This offers a greathealth advantage over traditional refrigerated air conditioning, which employs a complicated "closed"system that recirculates the same stale dry air over and over.Constant cool air movement pushes heat out -- along with stale air, smoke, odors and pollution.The high volume of fresh, cool air produced by the evaporative cooler helps your body ventilate naturally .Evaporative cooling helps maintain natural humidity level.