Why a Dehumidifier Won't Dehumidify

Concept of Dehumidification

• Dehumidifying involves manipulation of air temperature to achieve the proper level of humidity and moisture within a given space. Essentially, it applies heat to increase air temperature and reduce humidity, and then later will ventilate the area to release moist air and usher in drier external air. The unit capacity of a dehumidifier depends on two variable factors, according to Energy Star -- the size of the space and the conditions that exist in that space.

Effective Dehumidifiers

• In order to be effective, dehumidifiers need proper placement. Placing them away from walls and furniture will ensure proper air circulation. Dehumidifiers need ample space because they tend to have a high temperature to remove moisture in the air effectively. Therefore, it's important to determine the size of the space it will occupy. Smaller spaces may only require portable units; but for crawlspaces and basements, choose a unit suitable for spaces more than 1,200 square feet.

Benefits of a Functioning Dehumidifier

• When a dehumidifier works properly, it frees the air of airborne allergens. With the proper humidity level, wooden furniture, hardwood floors and wooden window frames last longer than those in homes without proper humidity. When you have a good dehumidifier, it lowers the levels of humidity in your home so that mildew and molds will not thrive. Exposure to mold can cause symptoms similar to having a cold or flu and can lead to respiratory problems, nasal and sinus congestion, coughing, skin irritations, watery eyes, sore throat and asthma, according to Kenneth Hellevang, Ph.D., or the North Dakota State University Extension Service.

Common Problems that Cause Dehumidifiers not to Work Properly

• Although, most providers offer maintenance packages, you need to know what to expect as well. For example, if the humidity is still high, you can adjust the control settings of your dehumidifier to make the air drier. Keep your dehumidifier clean. Dirty filters may cause your dehumidifier to not function properly. A burned coil or busted fan motor could cause your dehumidifier not to dehumidify. Most dehumidifiers don't work well under about 65 degrees Fahrenheit because the cooling coil would have to operate below freezing point to condense any moisture.

  Frost may form on the condensing coil of your dehumidifier when the temperature drops below 65 degrees Fahrenheit, causing your dehumidifier's compressor to cycle on and off repeatedly without removing moisture from the air. according to the Encyclopedia of Alternative Energy and Sustainable Living. Switching off the unit when this happens will allow the coils to defrost before turning the unit back on. If the space you're trying to dehumidify has a temperature that often falls below 65 degrees Fahrenheit, consider buying a dehumidifier specifically for lower temperatures or one that comes with an antifrost sensor that automatically turns off when the air temperature drops below 65.