Helps prevent mildew staining and damp walls combats odours and corrosion prevents damage caused by damp removes the possibility for mould and bacteria to grow the room dehumidifier removes all excess humidity down to the normal level of 50 the granules dissolve and the accumulated liquid is stored in the lower part of the device and then simply poured away for rooms of approx 50 60 m does not require a power source hence inexpensive to use long term effect ideal for storing it