An Air cooler is a device that is used to lower the temperature of the air in a room. Air coolers work by drawing in warm air which then passes over a cooling element and then releasing the cooled air back into the room. There are several different types of air coolers available, but one popular type is the evaporative cooler.

Evaporative coolers, also known as swamp coolers, work by using the natural process of evaporation to cool the air. These coolers contain a water reservoir, a pump, and a cooling pad commonly made of cellulose. The pump circulates water from the reservoir to the cooling pad which becomes saturated with water. Warm air is then drawn through the pad causing the water to evaporate and cool the air. The cooled air is then blown back into the room through a fan.

Evaporative coolers are extremely effective in hot, dry climates, as they add moisture to the air while also cooling it. They are also energy-efficient and can be less expensive to operate than traditional air conditioning units. However, as they add moisture to the air they may not be as effective in humid climates and will require regular maintenance to prevent the growth of bacteria and other microorganisms in the water reservoir and cooling pad.