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Preventing Damp Basements - Using a Dehumidifier

Submitted by Lorene Bartos, UNL Extension Educator

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Is your basement damp? Do you smell a musty smell in your house? The best way to get rid of the musty smell is to dry out the area. With rain and cool weather, dampness is a common problem. A dehumidifier can be a big help in getting rid of the damp air.

It is important to follow the manufacturer’s directions when using a dehumidifier. Keep the following in mind when you use one in your home.

Place the unit at least 6-inches from the nearest wall where air can flow freely to and from all sides. Avoid locating it in a room corner or near a large piece of furniture. Shut all doors and windows to the area to be dehumidified.

For the first few days of operation, turn the humidistat — if the model has one, to drier or "extra dry." This aids moisture removal from furnishings as well as room air. After the area has dried, adjust the humidistat to your particular comfort level.

Before emptying the water pan or bucket, turn the machine off and disconnect the power cord. This eliminates any possibility of electrical shock if you would spill water and there was a fault in the grounding system of the unit or your home wiring. Be sure the area, the unit and you are dry before you reconnect the cord.

Dehumidifiers operate most effectively at air temperatures about 70 degrees F. At temperatures below 65 degrees F., frost may form on the coils (which are kept cold to condense as much moisture as possible). If this happens, shut it off, and wait for it to defrost before running again. Frost cuts down air circulation so the dehumidifying process does not work, and may damage the coils. This problem usually occurs in cool basements in spring or fall; check the appliance if temperature hovers near that point.

As water condenses out of the air, heat is given off, raising the temperature slightly in the area around the appliance. This warmer air results in a lower relative humidity.

Features to look for in a dehumidifier are:

  • * mobility of the unit
  • * a tank easy to empty and clean
  • * an on/off switch
  • * an adjustable or electronic humidistat
  • * energy star rated

Most dehumidifiers have casters or wheels for easy moving, a six- foot power cord, a hose for drainage, a signal light and automatic shutoff, as well as a one year warranty on the entire unit and five years on the compressor.

It is important to clean the tank to keep mold and bacteria from growing. Tanks not emptying directly into a drain should be checked and emptied every couple days. The front grille should be vacuumed, coils wiped off and the air filter washed annually.

If you have moisture problems or dampness in the basement be sure to check for problems causing the moisture. Check for any causes of moisture inside and outside. A dehumidifer will help keep the area dry but the source of moisture must be identified.



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(This resource was updated May 2009 and appeared in the Lincoln Journal Star Newspaper Sunday edition. For information on reproducing this article or using any photographs or graphics, read the Terms of Use statement)

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University of Nebraska-Lincoln in Lancaster County
Web site: lancaster.unl.edu
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