The unit has simple controls on the top panel, select the relative humidity you want from four options 40, 50, 60%, or continuous. On reaching the desired humidity it should switch off. My unit is still running after a week of daytime running but a damp room can take up to a week or more to dry out. I must have emptied out around a good 10 litres. The improvement in the room conditions is very noticeable , much reduced mouldy smell and minimal condensation on the window.
For value for money I think this is a winner and providing it does switch off eventually I will know I am sleeping in a much more healthy environment.