Having purchased one on Ebay recently (no instruction leaflet :-( ), there doesn't seem to be any water going into the bottle, it's certainly working because the coils are cold and wet, and no blockage in the drain pipe to the container. There is a filter door air inlet on the back of the unit which is perforated and has a fine mesh (1/2mm) inside the door but there isn't a foam filter behind that although there is approx a quarter of an inch gap between it and a large holed plastic frame located between the door and the cooling coils. It looks as if it could hold a foam filter in between. I wondered if anyone has one of these dehumidifier units and could tell me if there should be a foam filter there. The introduction of a foam filter would slow the air velocity over the coils maybe increasing the efficiency of the dehumidification process?, I haven't measured the on coil/off coil air temperature as yet so cannot verify. However, the air velocity seems quite high (educated guess) and the cooling coil is only approx 1" deep as far as I can see without dismantling the whole thing.
Any advice please
Regards Don