I switch the unit on in the evening so that the humidity reaches a good 60% late in the evening and just let it run until the tank is empty. And then in the morning I ventilate it properly.
We have several units. One is in continuous operation. The other is only used a few times. We always change the filters after the winter season. It is important not to leave the water in the switched-off unit for a longer period of time, but to empty it out and let it dry out including the filter.
It is not the most quiet device, but it should not be shaking or very loud. Maybe check to see if there is something caught in the internal fan blades? The one we use is working as expected
The scope of delivery of Oskar little includes a filter and the Silver Cube. This means that Oskar little can be put into operation immediately. The filters in the set of 2 as well as in the set of 4 are compatible for all three Oskar models.