There are several products on the market that use natural substances to remove unwanted humidity from a room through a process called hygroscopy. They offer homeowners a handy solution in areas where an electric-powered dehumidifier is not desirable or practical, such as in a confined space like a closet, crawlspace or storage area – or even a small bathroom that does not have an exhaust fan to remove damp air. Employing measured quantities of calcium chloride or rock salt, they draw moisture from the air, which is then trapped in a container such as a pouch or reservoir that is easily removed and emptied.

It’s a convenient small-scale solution to persistent moisture accumulation, which, if left unattended, often leads to other problems such as mold, mildew and musty odors. However, because most of these products are not intended for large rooms – and do not normally take up a great deal of space – the accumulated water in these containers needs to be emptied regularly. Also, it’s worth noting that the raw material will need to be replenished, which results in an ongoing cost.