Sunpentown Portable AC units are equipped with an advanced condensation removal system: Self-Evaporating Technology (except WA-9000E, WA-1000E & WA-1205E). When running AC mode, this technology recycles the water condensation to cool off the cooling coils, then evaporates the water out with the exhaust air. This results in increased energy efficiency, cooling performance and reduces the need to empty the water tank. Under extreme humid conditions, the water condensation may collect faster than the unit can recycle. Should the built-in water tank becomes full, the compressor will automatically shut-off and water full indicator will blink. At this time, water should be emptied, which is a simple process.