What is a portable air cooler?
A portable air cooler is a device that utilizes evaporative cooling to provide an air stream that is cooler than the surrounding air. Air coolers, often called evaporative or swamp cooler, have a few main parts: the water tank holds water to be used in the cooling process, the wick absorbs water from the water tank and allows it to evaporate when air is blown over it, and the fan blows air over the wick and the water held in the wick.

To operate an air cooler, you must first fill the water tank with water. The bottom of the wick is immersed in the water and it "sucks" water from the tank and pulls up into itself. A fan is located behind the wick. It blows air over the wick and out of the machine into your room. As the air is blown over the wick, the water in the wick evaporates. Evaporation is an endothermic reaction (it absorbs heat) so the air that is blown over the wick and out into your room has had some of the heat absorbed out of it. Of course, the water that evaporated and absorbed heat from the air is carried out into your room as water vapor.

Air coolers work best in dry climates, and they are not very effective in climates with a high humidity, since they relay on water evaporating to produce cooling. Also, you should note that they do humidify the air, and as such are never a good option for cooling servers or electrical equipment.

Is this an air conditioner?
No, this is only an air cooler. Air coolers are often confused with air conditioners, but they have no compressor, refrigerant, or sealed system. A better way to envision them is as souped-up fans; they will cool the air they blow (by up to 12ºF), but they will not cool a whole room. They can not lower the ambient temperature in the room in which they are operating as an air conditioner would. The air stream that it provides is cooler than the ambient temperature, but once you step outside the air stream, you will no longer feel the cooling effects. However, an air cooler does not require a vent as an air conditioner would, and you do not need to empty any condensation bucket.

Does an air cooler add humidity to the air?
Yes, an air cooler does. It cools through the endothermic process of evaporation, and because of this, it adds some humidity to the air.

Do I have to fill it with water?
Yes, you do have to fill the air cooler with water to achieve maximum cooling.

How can I lower the temperature of the air stream?
Try putting ice in the water reservoir.

How long does the water last?
A full tank of water should last at least several hours of use on "High."