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Hot and muggy, muggy and sticky, there is nothing worse in summer than the heaviness of humidity. In fact, for some states it’s so bad that you’re drenched in moisture just to walk to the mailbox at the end of your short driveway. And when that humidity makes its way indoors, the days and nights can seem practically unbearable. Fortunately, there is a solution. Invented by Willis Haviland Carrier in 1902, dehumidifiers soon became the ideal way to cool the home. Over the years the dehumidifier evolved and today there are 3 main types of dehumidifiers.
All humidifiers work on the same basic principles, although each one varies a bit by type. Like an air conditioner, the dehumidifier uses refrigerant. However, it doesn’t cool the air … it actually warms it up a bit, which lowers the humidity and makes the room more comfortable. This is done using a fan, hot and cold condenser coils, and a water tank.
The heat pump dehumidifier is used to draw water out of a building by using a heat pump that works much like an air conditioning pump. A fan is used to move air through an icy coil and cause moisture to condense. The drops are then collected in a bucket inside the unit. The air is then heated by a second coil and then released back into the room at a comfortable temperature. The heat pump dehumidifier is considered the best available.
In large industries, especially those in warmer climates, the most common type is a chemical absorbent dehumidifier. This type uses a chemical drying agent that works with a heat exchange wheel to absorb water molecules from the air. The process draws the humid air out through the vents.
The third type of unit is the dehumidifying fan. These work with a sensor controller and an exhaust fan. These are less effective in climates where humidity is especially high because fans draw outside air into the home. Rather, the dehumidifying fan works great in basements but you need to pay close attention to how it works as it can depressurize a room and cause gas spills … just make sure if you have a gas oven you have the adequate ventilation and you’ll be fine.
If you already have a dehumidifier, but it doesn’t seem to be working properly, there are a few things you can do. First, you’ll want to make sure it’s the correct size unit for the space you’re cooling; then after turning off the unit, check the following:
- Remove the cap and clean the condenser and evaporator coils.
- Lubricate the fan motor bearings, if the motor has oil ports.
- Make sure the humidistat is working properly by testing it with a volt-ohm. Turn the humidistat knob as far as it will go in either direction. If it reads 0 during the whole process, it’s time to replace the drive.