What is a Dehumidifier – Definition and Use

DeLonghi-DD50PE-DehumidifierWhat is a dehumidifier?

A dehumidifier is a common appliance which can remove excess moisture from your interior air. They can come in different physical sizes, shapes, prices and capacities. Generally, there are two types of dehumidifiers. Whole house dehumidifiers mostly work with your home heating system to remove excess moisture throughout your whole house. Of course, they are pricier, while portable dehumidifiers allow you to move them to the areas where excess moisture is presented.

Why do you need one?

Some air condition systems may have a built-in dehumidifier. However, the most common dehumidifiers are portable dehumidifiers that specialize in reducing the humidity level in a room.

A dehumidifier can remove excess moisture, while its opposite appliance is a humidifier that can add moisture in the air. They are all moisture-control appliances, but work oppositely.

Maintaining a proper humidity level can make the room healthier and comfortable. And such a proper humidity level is very important to our health. Too much moisture is helpful to the growth of mold and mildew and cause serious damage to wooden musical instruments, furniture, carpets, clothes, as well as other textiles.

Even if you have used your wet or dry vacuum to get rid of water caused by spring runoff, a certain amount of moisture is also presented in the interior air. You may think you can use a heater to dry the air, but this can be an energy-intensive choice. A good way is to use a dehumidifier which can efficiently expel excess moisture from the air. And it can remedy the humid situation quickly.

If you are not sure whether you need a dehumidifier, some signs can tell you that you really a dehumidifier. For example, if there is very wet in the basement or you even see some damage, a basement dehumidifier is essential. A wet room feels colder than other rooms. A hygrometer is a good tool for you to know the accurate humidity level in your room. And you also need to pay attention to the reading results even if you are using a humidifier. Once the humidity level is too high, you may need to turn off your humidifier.

How does it work?

A portable dehumidifier is used to remove moisture from the interior air in the room. The removed moisture will become liquid water and be stored into a built-in water bucket. When the bucket is full of water, it is time to empty it, or the room dehumidifier will automatically stop it. Some units come with automatic drain options which can drain the water in the bucket when it is full, so they can work continuously for several days.

Different units have different capacities and just remember large units are more difficult to move from one place to another place, but larger ones may come with larger water tanks which don’t need to be emptied too often. If a unit comes with a built-in humidistat, this means you can adjust the humidify level. It is really a good feature.


The prices of portable dehumidifiers vary widely, from $100 to $400, which depends on the output and capacity. However, a whole house dehumidifier may cost you from $1,000 to $2,000, depending on capacity and output. Before making a buying decision, something needs to be considered. First you need to know if the excess moisture is an area-based problem or a whole-house problem. And you also need to know the moisture problem is a seasonal problem or an ongoing problem.


No matter what types of electrical appliance you plan to buy, make sure they are UL certified, because safety is always the first consideration when buying an appliance.

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