A standard portable air conditioner unit requires no filling of any kind. To the contrary, it requires drainage to sustain a cooling effect. An evaporative portable air conditioner, on the other hand, requires filling and refilling of the water tank and icebox to function at all.
Evaporative Unit Vs. Standard Unit
An evaporative or humidifying portable air conditioner doesn't require window installation. A regular portable air conditioner comes with a hose attachment that connects from the unit to the window to exhaust impure air from the room to the outside air. An evaporative unit requires no hose. A regular portable AC draws moisture from the air whereas an evaporative unit uses moisture to cool the room. An evaporative unit's internal tank must be filled with water as opposed to a regular portable air conditioner's internal tank, which must be emptied to properly function.
The water tank on an evaporative air conditioner unit is located beneath the vents on the front and back of the unit. A water volume index marks most tanks so that you can see how much water is inside. The tank should always contain water or the unit fails to run. An ice and water inlet, where ice and water can be poured, folds out on the side of the unit. Ice and water are used when filling the water tank.
An extra icebox component is located on top of the unit above the front and back grilles. The icebox can be filled and refilled with ice to enhance the cool air function of the evaporative air conditioner. Ice packs can be loaded into the icebox component instead of ice cubes. While the icebox component works in conjunction with the ice and water tank, filling the icebox isn't necessary.
When you fill the water tank or icebox, the power to the evaporative air conditioner unit should be off as a safety measure. Water and ice pour into the open water and ice inlet on the side of the unit until the water volume index indicates that the tank is full. The index must be at least above "Empty" for the unit to run but shouldn't be filled above its maximum setting. Sunpentown recommends filling the tank with one part ice and two parts water. The icebox lid lifts off to allow easy insertion of ice or ice packs.