For the dehumidifier to work properly you should place the dehumidifier in the room that is the most humid such as basement, bathroom or even laundry room.
Basically any room in your house that is the most humid is where the dehumidifier should be placed.
Also it's best to place the dehumidifier into the center of the room if possible or if that's not possible place the dehumidifier at least 6 to 12 inches away from walls and furniture for optimal performance of the dehumidifier.