Humidifier Vs. Dehumidifier: What’s The Difference? [Compared From 4 Aspects]

Liz Yang

Indoor air quality is critical for the health and safety of our homes. Fortunately, we now have a plethora of useful household appliances to assist us in controlling it. As for humidity control, people often use humidifiers or dehumidifiers. 

What’s the difference between each other? While both are responsible for controlling the indoor humidity level, a humidifier is for improving the humidity, whereas a dehumidifier is for reducing the moisture in the air. 

However, this is just a short answer to this question. I will compare them from 4 different perspectives in this post. By continuing to read, you will have a firm understanding of these two devices and will know which one is a better choice for you.

Humidifiers vs. dehumidifiers:  work on different principles

The fundamental difference between humidifiers and dehumidifiers lies in how they work. In fact, many people don’t have a clear picture of these two electronic devices. As a result, I’d like to give them a brief introduction here.

How does a humidifier work?

A humidifier adds moisture to the air by dispersing water vapor or mist. It comes with a water tank, which you should always refill. This machine converts the water in the tank into moisture in the air.

Different types of humidifiers

Humidifiers are classified as warm mist humidifiers and cold mist humidifiers.

Warm mist humidifier

A warm mist humidifier or vaporizer, as the name implies, uses heating elements to boil the water in the tank and then uses the water vapor to add moisture. Different warm mist humidifiers operate on similar principles.

Cool mist humidifiers

There are more types of cool mist humidifiers for you to choose from.

Ultrasonic humidifiers are the most common type nowadays; they break down water into tiny moisture particles using a high-frequency vibration produced by a membrane.

Evaporative humidifiers generate water vapor through evaporation with the help of a fan. The water will pass through a wick or filter before being expelled into the environment, making it a more sanitary option than an ultrasonic humidifier. Nonetheless, it will make more noise due to a built-in fan.

Impeller humidifiers are no longer widely used. It uses a rotating disc to fling water onto a diffuser and disperse the water particles into the air.

How does a dehumidifier work?

A dehumidifier reduces indoor humidity by removing moisture from the air. Dehumidifiers, like humidifiers, have an internal water tank. In contrast to humidifiers, this bucket collects water from the air.

Different types of dehumidifiers

Two types of dehumidifiers are usually used in the home.

Compressor dehumidifiers suck up the air by means of a fan. When warm air passes through the chilled coil, moisture condenses and turns to liquid. The dry air will then be reheated and pumped into the room. But this type of humidifier is not appropriate for use at low temperatures.

Desiccant dehumidifiers employ a large desiccant wheel to absorb the moisture and then use a heater to remove the water in the wheel. Desiccant dehumidifiers can function in cold climates but are less energy efficient.

Humidifiers vs. dehumidifiers: different health benefits

The ideal humidity level ranges from 30% to 50%. When the humidity level falls below 30%, you should use a humidifier; when it exceeds 50%, you should use a dehumidifier.

If you don’t have a hygrometer, you can judge the humidity level by looking for signs of dry or humid air.

They can combat the discomforts caused by dry air and humid air separately, as shown in the table below.

Simply put, dry air can promote the growth of bacteria and dry out the mucous membrane, making it susceptible to infections and inflammations. Dust mites and mold thrive in humid air, posing numerous health risks to you.


Health benefits of using humidifiers

Health benefits of using dehumidifiers
Improve sleep qualityPrevent sleep disorder
Soothe dry skin.Avoid mold and dust mite allergies
Relieve sore throat.Prevent bronchitis.
Relieve sinus congestion.Relieve shortness of breath.
Prevent bronchitis.
Prevent nosebleeds.
Prevent colds and influenza.
Reduce allergies and asthma attacks caused by viruses, pollen, and other bacteria.
Reduce static electricity.

You see, both dehumidifiers and humidifiers can help in relieving allergies, asthma flare-ups, and bronchitis because the contaminants in both dry air and damp air can trigger these symptoms. 

Humidifiers vs. dehumidifiers: effects on your property

In addition to health, the humidity will also affect the safety of your house and the state of your furniture. The indoor air that is too wet or too dry will wreak havoc. This is even crucial when you have a lot of wood around. 

Dry air can cause wood to shrink and creak, whereas humid air can cause swelling and wrapping. The fungus will also eat the wood, causing structural damage. A humidifier can combat the negative effects of dry air on your property, while a dehumidifier can eliminate the impact of excess humidity in your home.

Effects of humidifiers on propertyEffects of dehumidifier on property
Prevent air leakage from shifting wood door and window frames.Prevent paint bubbles
Avoid shrinking on wood furniture.Prevent peeling wallpaper
Prevent hardwood floor separationAvoid the growth of wood-eating fungi and protect the home structure.
Keep the wood furniture from swelling and warping.
Reduce the likelihood of mold appearing on the wall.

Humidifier vs. Dehumidifier: which one is more affordable?

As I mentioned at the beginning, the difference between humidifier and dehumidifier boils down to different working principles. 

Generally speaking, dehumidifiers involve a relatively more complicated working process. Accordingly, it is made of more components, which can add up the cost. Therefore, dehumidifiers are usually a bit more expensive than humidifiers. 

A dehumidifier, on average, is around $150 to $250, whereas a humidifier will only cost you around $50.

Humidifiers vs. dehumidifiers: which one consumes more electricity?

The wattage of humidifiers is usually lower than dehumidifiers. The average wattage of a humidifier ranges from 30W to 70W. However, the average wattage of a dehumidifier is about 400W, meaning that it consumes 10 times the amount of electricity as a humidifier.

Anyway, dehumidifiers don’t use a lot of electricity either when compared to other household appliances such as vacuums and hairdryers. Assuming you run a dehumidifier 8 hours a day and every day in a year, it will cost you about 172 dollars.

What’s the difference between a humidifier and a dehumidifier overall?

The function of a dehumidifier is opposite to that of a dehumidifier. A humidifier adds moisture to the air, whereas a dehumidifier removes excess moisture from the air.

As a result, a humidifier can combat dryness and symptoms caused by dry air, such as dry skin and sore throat. Mold and dust mites can be prevented from growing with the help of a dehumidifier.

Since a dehumidifier contains more parts and has a complex operation, it will cost you more than a dehumidifier. Meanwhile, a dehumidifier will use more electricity than a humidifier. 

All in all, you just need to remember to use a humidifier in dry climates and a dehumidifier in a moist environment.

Liz Yang is the founder of Airsmartly. She has been working at home for a few years and realizes that the performance of the HVAC system plays such an important role in our life. She has tested a lot of products in person, like humidifiers, air purifiers, dehumidifiers, and ACs, and wants to share tips about using or troubleshooting these products with you. Her uncle is an HVAC expert with over 30 years of experience in the field, and often offers assistance when she is unsure how to handle a situation. He is also in charge of reviewing the articles on this site.

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