Philips Respironics has you covered when it comes to replacing your Humidifier Dry Box for the DreamStation. As a replacement assembly, the main purpose is to prevent internal water damage to the DreamStation Heated Humidifier and the DreamStation CPAP machine itself. It will also act as the path traveled for the humidified air to flow between the machine and humidifier.
Taking a page out of the PR System One, Respironics brought back the Dry Box technology as it was successful in preventing water leakage between the water chamber and the device. Should the water spill from the water chamber it will be caught by the dry box and kept from spreading throughout the humidifier thus keeping everything safe.
Though this piece is meant to prevent any accidental water spills that may occur, it is not 100% fool proof as it is a one direct valve. It is best to handle your humidifier with the utmost care during the time it is having water filled into it. Located on the interior of the humidifier is the small inlet seal just as there is also a small seal placed on the exterior of the device where machine meets humidifier. Keep in mind that the only piece that is supposed to be replaced is the interior piece. In the event that the exterior peice comes off or is damaged then it will require a new assembly to be purchased.