Appliances & Lighting

Keep Dehumidifier Operating Costs Down

Trying to cure a damp basement with a dehumidifier? Beware. A small dehumidifier can use $50 or more a month in electricity. Depending on the size of the appliance and run time, dehumidifiers can be a sizable part of your electric bill.

What it costs
It's easy to figure how much a dehumidifier will impact your electric bill by using this formula. First you'll need to take a look at the appliance's nameplate and record the figure in the blank marked "amps." The nameplate may be located behind the removable drain bucket. Next, estimate how many hours the dehumidifier runs each day.

0.288 X (amps from nameplate) X (hours unit runs per day) = $ per month

Example: Nameplate amps are eight and unit runs 24 hours a day.

0.288 X 8 X 24 = $55.30 per month

Consider the alternatives
Lowering energy bills stemming from dehumidifier use starts with stopping moisture from entering the basement. Some tips:

  • Correct outside drainage problems. If gutters dump water next to your home's foundation, add extensions so the water will drain away from the house. Also make sure the soil next to the foundation slopes away from the house to carry away rainwater.
  • Waterproof basement walls and floors. A coat of vapor barrier paint may keep the invading water in check.
  • Use exhaust fans in the kitchen, bathroom and other high-moisture areas of the home. Beware of faux kitchen vent hoods that merely circulate air and water vapor back into the kitchen. Both kitchen vent hoods and bathroom fans should be piped to the outdoors.
  • Don’t use contraptions that allow clothes dryers to vent to living spaces. Quarts of water in the damp garments end up inside, adding to water woes.

Keep operating costs down
When using a dehumidifier is necessary, follow these steps to reduce energy costs.

  • Use a hygrometer to measure relative humidity in the problem area and determine if the moisture level is higher than the recommended 50 percent. You can find electronic hygrometers starting at $25 to $30.
  • When choosing a dehumidifier, match its moisture-removing capacity to the size and dampness of the space. Manufacturers have charts to help with this (Look on the Association of Home Appliance Manufacturers Web site, listed below).
  • Run the dehumidifier on lower settings first so the unit will cycle instead of operate continuously. Increase the setting as needed until mold and mildew disappear.
  • Delay installing a hose for continuous drainage of the dehumidifier so you'll get a feel for the amount of water being removed as you empty the drain bucket.
  • Keep closet doors open in the affected area so air can circulate through them.
  • Regularly clean the unit's coils so it runs at top efficiency.

Home Moisture (
UGA Cooperative Extension Service (
Canadian Housing (
American Home Appliance Manufacturers (