It really does not work well. I have a very small bathroom. I've tried this dehumidifier with the window open, with the window closed, during hot water showers, colder water showers, every single time, there is still so much condensation on all the walls. I keep the dehumidifier on from before I enter the shower until after the bathroom door has been open for a while after the shower and all the condensation has left the mirrors. Maximum, there are a few drops of water in the dehumidifier.