A dehumidifier is a useful device that reduces a room's humidity level by removing moisture from the air. Similar to air conditioners, dehumidifiers have an internal fan that draws in the room's air. That air then runs through a cold coil, which condenses the moisture. That moisture is collected into a bucket or a reservoir that is emptied when it gets full. The dry air runs through the hot coil where it is heated back to its original temperature, keeping the room comfortable.
Since the cold coil condenses the moisture, a dehumidifier is usually not necessary if there is air conditioning in the room. While we all need a certain moisture level to be comfortable, too much moisture can cause mold, mildew, and odors to grow. It can also make life pretty uncomfortable.
High humidity levels can aggravate health problems such as arthritis, rheumatism, and asthma. Dehumidifiers are particularly useful in low-vented areas such as damp, un-cooled basements. There are various kinds of dehumidifiers with varying levels of effectiveness.
Heat Pump Dehumidifiers
Heat pump dehumidifiers use a heat pump which removes moisture from the incoming air, but does not actually cool the air. When the air hits the cold internal coil, it condenses and builds up enough moisture to collect in the bucket and drain. The other coil reheats the air, releasing it back into the room at a normal temperature.
Chemical Absorbent Dehumidifiers
Chemical absorbent dehumidifiers are best suited for excessively hot and humid conditions. These units collect moisture from the air with a desiccant, which is a chemical that absorbs water molecules and therefore, acts as a drying agent. It is able to eliminate the hot moist air through a duct. Chemical absorbent dehumidifiers use natural gas and operate at a higher energy level, which can be costly, depending upon gas natural gas prices.
Dehumidifying ventilators are an excellent money-saving choice. Because they run on sensors, they can detect when humidity levels are getting too high and operate only when needed. Although not the ideal choice for extremely humid areas, they do use less electricity than heat pump dehumidifiers and do not utilize a heating device.
These devices can cause gas spillage, however, so thoroughly inspect gas furnace vents before use.
Dehumidifier Purchase Tips
Dehumidifiers are not all alike. There are a wide variety of models available. Look for dehumidifiers with a high efficiency factor. Keep in mind that the moisture the unit is able to collect, the more expensive it will be. Compare the water removal capacity of various models. This indicates the number of pints of water that can be removed from the air over a 24-hour period.
Here are some other features you should consider when buying a dehumidifier:
- Low noise level
- Automatic turn-off switch that activates when the catch basin is full
- Indicator light that alerts you when the container is full
- Automatic humidistat that allows you to dial in the desired humidity level
- Automatic defrost control
- Integrated heater to warm a cool room
- Extra-quiet fans and compressors
- Rustproof and spill-proof cabinet
- Fitting for an outlet drain hose
- Wheels or casters.
Dehumidifiers are not complex machines and should be placed where they can achieve maximum airflow through the room. If the catch basin doesn't have an outlet pipe that runs to a nearby floor drain, then empty the basin when it becomes filled with water. The coils should be checked to make sure they're clean, as accumulated dust can reduce their efficiency. Be sure to schedule routine maintenance and regularly check your dehumidifier as necessary.