Buying Guide: Dehumidifiers

The amount of moisture or water vapor in the air is called humidity. Humidity can be added to the air when people or pets breathe and perspire, by indoor plants, and through routine household tasks like cooking, showering, bathing, doing laundry and dishwashing. Too much humidity in your home can cause a host of difficulties. For example, excess moisture in the air can cause condensation on windows, wet stains on walls and ceilings, moldy bathrooms, musty smells and allergic reactions. More long term effects include damage to the house and its contents, ongoing allergies and other health problems. The perfect solution to excess household moisture is to purchase a quality dehumidifier. They are household appliances that help reduce the humidity levels in the air.

For very small spaces, desiccant or passive dehumidifiers can be used. For larger areas, mechanical dehumidifiers are more common and more efficient. Mechanical dehumidifiers are dehumidifiers that use compressors. They are very similar to air conditioners, except that they contain hot and cold coils in the same box. To condense the moisture, a fan draws air over the cold coil and the moisture is collected into a bucket. To heat the air back to its original temperature, the dry air will pass through the hot coil. The temperature on the air is slightly raised by mechanical compressor dehumidifiers.

There are also dehumidifiers with thermo-electric peltiers. These mechanical dehumidifiers pass an electric current through two dissimilar metals that transfer heat and cause the same effect that is used by mechanical compressor dehumidifiers. These units operate extremely quietly because there are no moving parts and the only noise emitted is from the fan that circulates the air. Thermo-electric peltier dehumidifiers are very effective for smaller areas because although they are not as energy efficient as units with compressors, they provide nearly silent operation. Here are the features to look for when purchasing a dehumidifier:

Portability: This is an important feature if you need to dehumidify more than one room. Look for a unit that has a compact body complete with a carrying handles and rolling casters.

Built-in Humidistat: This feature allows you to set your desired humidity on your unit. After you set your desired humidity level, the dehumidifier will cycle on an off until it reaches that moisture percentage.

Automatic Shut-Off: Finding a unit with this feature is important is you want your dehumidifier to turn off by itself when the storage tank is full to prevent overflowing. The NewAir AD-40A Dehumidifier shuts off when the tank is full and will not run until the tank is emptied and replaced.

Automatic Defrost: Sometimes frost may build up on the coils of your dehumidifier. Automatic defrost stops the operation of the unit and runs the fan until the coils have defrosted. This prevents frost from accumulating on the sensor and prevents quick cycling.

Storage Tank Capacity: Note the storage tank capacity whenever you are purchasing a dehumidifier. You should purchase a dehumidifier with a tank that is an appropriate size for the area that needs to be dehumidified.

Continuous Drainage Port: A continuous drainage port is very convenient because your dehumidifier can run continuously and the water is constantly being drained. If you purchase a dehumidifier without one, the tank will need to be emptied regularly.

Indicator Lights: Indicator lights are important because they alert you when something happens that might affect the way your dehumidifier operates. The NewAir ADS-600 Mini Dehumidifier has a red indicator light that indicates when the tank is full. There are also indicator lights on some units that tell you when the filter needs to be cleaned or replaced.

Built-in Air Purification: If you need to remove excess moisture but also impurities from the air, look for a dehumidifier with this feature. The NewAir ADS-500 Mini Dehumidifier eliminates allergens with a built-in ionizer and absorbs odors with the activated carbon filter.