Keep Your Basement Warm and Dry

by Frank McChristian

Humidity refers to the amount of moisture in the air. And you might be surprised to know that the air in our atmosphere has water in it. Lots of water! This becomes extremely problematical in the case of basements, where excessive humidity can easily lead to the development of mold and mildew, provoking allergies and other health problems. One very efficient way in which you can take control of your basement environment is by using a dehumidifier. Without one, the usefulness of your basement would be very limited. But what is a dehumidifier and how does it work?

A dehumidifier is essentially a refrigerator in that they both share the same basic mechanical function – compression and expansion of a gas used to lower the temperature of metal coils to freezing temperatures. However, instead of the cooling action being directed into a closed box, a dehumidifier is designed to blow warm moist room air over these cold coils. The moisture in the room air condenses on the coils to become liquid water. The water then drips into a drip collection pan, or to a drain. The room air, now freed of much of its moisture, returns to the room slightly warmer than it was.

Dehumidifiers are controlled by a device known as a humidistat. This is an adjustable rotary switch that detects moisture in the room’s air. It automatically turns the dehumidifier on or off as it is needed, based on the setting you choose. If you wish, you can set the dehumidifier to the maximum setting for continuous operation.

If you utilize your basement as a living space, or if you store valuable items there, then it is vital to keep the moisture level low. Moisture can cause mildew growth and damage furniture, photos, carpets and virtually anything else. Unlike the rest of your home, the parts of your foundation that are below ground level, or “grade,” is constantly in contact with moisture from the earth outside. Though some homes have adequate vapor and water barriers installed outside their foundations, many older homes do not. Unknowingly, people destroy their valuable possessions by not taking steps to lower the level of moisture in their basement’s air.

What size dehumidifier should you buy? There are arguments for both large and small dehumidifiers. Large ones remove moisture faster, so they operate for shorter periods of time. However, there is more electricity used per hour to run a larger dehumidifier. However, the advantages of size are most noticeable when dehumidifying a large area. A small dehumidifier may run continuously and still never lower the humidity to an acceptable level. A larger unit, by dehumidifying a larger amount of air per hour, can keep up with the demands of a large room.

How often you should run your dehumidifier depends on the temperature of your basement and your local climate. Dehumidifiers do not function well at lower temperatures, so under 65 degrees it is almost a waste of money to run them. Plus, as the air temperature drops, the risk of freezing the coils increases. If you heat your basement, the warm air will move moisture from the basement to the house above, keeping the humidity lower in the basement and slightly humidifying the rest of the house. In areas where the ground is frozen for most or all of the winter, the amount of moisture that will migrate through the basement floor and walls will drop dramatically in the winter, so the need for dehumidification decreases. However, if you live in a temperate area, and your basement is not heated, you may have to run the dehumidifier year round.

To keep your dehumidifier in good working order, check the coils at least seasonally and keep them clear of dust and dirt. If the unit has a removable front cover, there may be a foam filter inside that should also be cleaned. The purpose of this cleaning is two-fold. First, dust and dirt can insulate the coils from the room air, decreasing the efficiency of the dehumidifier. Secondly, this same dirt will get damp and possibly freeze. Freezing is the most damaging thing that can happen to your dehumidifier because it will run continuously but not dehumidify the air. This will lessen the life of the unit and you will then have to purchase another one. Not to mention that you will notice a steep rise in your electric bill. For more information about dehumidifiers, visit http://www.applianceaid.com/dehumidifier.html