Dehumidifier works

A dehumidifier is generally a household appliance which reduces the level of humidity in the air, usually for health or comfort reasons, or to eliminate dank smells. Humid air can cause mold and mildew to grow inside homes, both of which pose numerous health risks. Very humid climates or air make some people extremely uncomfortable, causing excessive sweating that can't evaporate in the already-moisture-saturated air. It can also cause condensation that can disrupt sleeping, create a situation where the cold pipes in this area begin to drip (from the condensation), and can prevent laundry from drying thoroughly enough to prevent mustiness. Lower humidity is also preferred because it limits the population of most pests, including clothes moths, fleas, cockroaches, woodlice, and dust mites. Relative humidity in dwellings is preferably 30 to 50 percent.[1]

By their operation, dehumidifiers produce an excess of water which has been removed from the conditioned air. This collected water, usually called condensate in its liquid form, is not potable and cannot be used for drinking, so it must be discarded.[2] Some designs, such as the ionic membrane dehumidifier, dispose of excess water in a vapor rather than liquid form. The energy efficiency of dehumidifiers can vary widely.

Dehumidifiers are also used in industrial climatic chambers, to reduce relative humidity to levels conducive to processing of certain humidity-sensitive products.