"Air Coolers are also a medium of cooling the rooms when the temperature outside is hot and humid. The basic principle behind the working of air coolers is that they use the hot air and water to cool the rooms within the house. There are different kinds of air coolers like the evaporative coolers, desert coolers, and the portable coolers. These air coolers also vary in size. For example, the portable air coolers are obviously much smaller in size while the desert coolers have a larger size requiring more space, water, and power. Hence, in order to get the most effective cooling, certain factors need to be considered. They are the following:Climate: Air coolers are not a very good option for regions which have a high humidity because when there is moisture already present in the air, it might be quite difficult for further evaporation to take place.The type: If you have a larger area to cool then it is recommended to opt for a desert air cooler while in case of a smaller area, a portable air cooler will suffice.The features: While buying an air cooler, you should look for certain features like the thickness of the cooling pads, speed controller, automatic water level controller, shut-off dampers and a remote control.The running cost: It is a good idea to buy an air cooler with an inverter technology because that will help in saving electricity."