Dehumidifiers take moisture out of the air. That moisture is then transformed into water. A continuous drain option means that the water that accumulates in a dehumidifier can constantly be drained into your water system. The alternative would be models that have a water reservoir that needs to be emptied periodically. If you live in a very humid climate, then having a continuous drain option is exceptionally handy. By hooking up the water hose to your house’s drainage system, it eliminates the need to remember to empty the water reservoir. Plus, most models will automatically stop working if the water reservoir becomes full. A continuous drain option means that your dehumidifier can work around the clock without you having to worry about it.