Most modern window air conditioners create condensation which drips down to the pan on the bottom of the unit.   There are no drain holes or plugs used to remove the water as was the case with older style window AC units.  When the water builds up it is distributed by the fan sling and thrown up against the condenser.   This helps lower the air conditioner's temperature making it more efficient.   If the amount of water is high the fan may create a sloshing sound as it makes contact with the water.  This is the normal operation.   If the water level gets too high it will drip out the back side of the AC unit.  Make sure the AC unit is install properly, with a slight angle so that the condensation drains towards the rear of the unit.