The humidifier works well. The filter can be replaced and it's a good idea to check it often because you don't want it to get moldy. We often bought extra filters to have on hand to replace. During the dry winter months in Alaska we have found that a moderate sized humidifier works well in our bedroom. We turn a humidifier in our bedroom while we sleep. I like to keep humidifier fans on low so that the background noise is moderate and not to loud to make at night. Covering the light on the units will also keep you from waking and this can be done with tape or even a small towel. Adding warm water to the humidifier in the evening seems to work well too.