Humid basements may need dehumidifiers to stave off mold and mildew, but you can probably keep your machine at a relatively low setting.

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If you live in a dry region, you may not be very familiar with the dehumidifier. It's an appliance that removes moisture from the air. In very humid, wet areas, like South Florida or the U.S. Northwest, this can be crucial for health reasons, since too much water vapor in the air can cause mold to grow and can make a cozy environment for dust mites. It can also cause damage to belongings placed in storage.

Lots of people leave dehumidifiers running all the time. That's why they're such a huge power consumer: It's a high-wattage appliance that runs for long periods of time. A dehumidifier comes in at anywhere from 60 to 1,000 watts, depending on capacity, with an average somewhere around 785 [source: Energy Savers]. Using a dehumidifier might consume 160 kWh/month, which is probably more than your refrigerator uses [source: CPPD].

Of course, how much energy a dehumidifier actually uses depends on how long it runs and where its humidity level is set. To make sure your appliance isn't wasting energy:

  • Close off the room (shut doors and windows) where the dehumidifier is working. A single-room dehumidifier can't efficiently remove moisture from the whole house.
  • Set the humidistat at a reasonable number. Fifty-percent humidity is considered average for basements. If it's set lower, the unit might end up staying on all the time.
  • Upgrade to a digital humidistat (instead of a dial) for greater precision.

Up next: Hot showers, high bills.