A dehumidifier drain hose connects to the reservoir of a dehumidifier and allows the water it removes from the air to flow directly into a floor drain. This eliminates the need to manually empty the reservoir. Some dehumidifiers have a pump inside the reservoir to speed the emptying process.
Portable dehumidifiers can remove from 35 to 70 pints of water from the air every 24 hours, so the drain hose reduces the work they require. They work much like air conditioners. Air passes over coils cooled with refrigerant, causing moisture to condense and drip into the reservoir. Owners place them in damp spaces, such as basements, to lower the humidity in the air.
Most dehumidifiers have a humidistat that senses the humidity level in the air and shuts off the unit when the humidity level reaches the preset value. Units without a drain hose also have a sensor that turns off the machine when the reservoir is full.
There are several indicators that a home needs a dehumidifier. Water stains on the walls, rotting wood or mold are often signs the humidity in an area is too high. Installing a machine and setting the humidistat to 50 percent is often enough to prevent the moisture problem.