Air coolers, also known as evaporative coolers, are devices that use the evaporation of water to cool the air. They consist of a water tank, a pump to circulate the water, and a set of cooling pads. Air is drawn through the cooling pads, which are kept wet by the circulating water, and as the air passes through it, the water evaporates and cools the air. The cooled air is then blown into the room by a fan.

Air coolers are more energy-efficient than traditional air conditioners, as they use less electricity and do not use refrigerants. They are also more environmentally friendly and produce less greenhouse gas emissions. They are also less expensive to operate and maintain. They are suitable for use in a variety of environments, including homes, offices, and industrial facilities. They are also more efficient in dry and hot climates, as the process of evaporation is more effective in these conditions. They are also relatively easy to install and maintain. However, they need to be filled up with water and the water needs to be changed regularly to prevent mold and bacteria.