An air cooler, often called a swamp cooler, is an eco-friendly cooling device that uses the natural process of **evaporation** to lower air temperature. Unlike traditional air conditioners that rely on chemical refrigerants and compressors, an air cooler draws warm ambient air through water-saturated pads. As the water evaporates, it absorbs heat, and a powerful fan circulates the now-chilled, humidified air throughout the room. They are most effective in **hot, dry climates** where they can significantly drop temperatures while consuming a fraction of the electricity required by standard HVAC systems.