What is the Difference Between a Humidifier and a Dehumidifier? – The Ultimate Faceoff 

what is the difference between a humidifier and a dehumidifier

Imbalanced humidity in your surrounding air can cause adverse effects like allergies, sore throat, and dryness of your skin or hair. Nobody wants a bad hair day every day, do they?

Depending on whether you have too much or too little humidity, you need to decide what machine does the job for you – a humidifier or a dehumidifier. But first, you’re probably wondering what exactly is humidity, and what is the difference between a humidifier and a dehumidifier?


Humidity is associated with precipitation and rain, however, there’s much more to it. In simple terms, the number of water molecules present in the atmosphere determines humidity. The higher the amount of water vapor, the higher the humidity is, and vice versa.

Relative humidity (RH) measures how much water vapor there is in the atmosphere compared to its absorption by the air. This absorption differs for different temperatures.  

Hot air tends to hold more water molecules than cold air due to faster evaporation at high temperatures. So the hot air will contain more moisture and has greater absolute humidity than cold air.

Absolute humidity is the actual amount of moisture in the air regardless of the air’s temperature. It is expressed as grams of water vapor per cubic meter volume of air.

Humans are sensitive to humidity as bodily functions like sweating and skin conditions rely on humidity. Humidity affects the amount of heat our bodies can give off through evaporation, so it is important to maintain certain levels of humidity around us. 

Relative humidity between 30 to 60 percent is the most preferred as a comfortable humidity level, whereas the ideal humidity level for indoors is between 30 to 50 percent.

You may be wondering why you have a runny nose or a dry throat despite ambient temperatures at your house. The answer is simple: it is because of the humidity levels that surround you. 

Failure to maintain optimal humidity levels can take a toll on your health. Let’s discuss the adverse effects of humidity so you can make the right decision about whether you need a humidifier or a dehumidifier. 

Effects of Humidity

Holding Temperature and humidity Thermometer

There’s a popular saying: an excess of anything is bad. Humidity levels that are too high or too low can harm your health in different ways, as well as your surroundings.

Problems Associated with High Humidity Levels

You might have noticed that we feel lethargic or low on energy when it’s hot. This is due to the inability of our body to expel heat as the temperatures in the surroundings are already high.

High temperatures combined with extreme humidity levels trigger allergic reactions, asthma, and dust mites. It also can make you feel exhausted or fatigued and increases the risk of a stroke. 

Excessive sweating can also happen in such situations, which can dehydrate you and cause heat stroke.

Extreme humidity negatively affects your home as well. It can cause condensation on windows, stains on walls, musty odors in bathrooms, and damage the overall structure of your house. 

When these issues arise, your home probably needs a dehumidifier.

Problems Associated with Low Humidity Levels

Chapped lips and dry skin are not always because of negligence in your ten-step skin regime – sometimes it’s due to low levels of humidity. The loss of moisture in the air can adversely affect mucus membranes causing respiratory problems, itchy skin, cracked lips, and even a sore throat.

It causes further havoc when we talk about the effects of low humidity in our homes. Shrinking wooden items and loose drawers are not the work of a supernatural force but rather a lack of moisture. In low humidity situations, you may notice peeling wallpaper, gaps, and other malfunctions around the house. 

You may also feel static electric shocks upon contact with home appliances or vehicles, and even possibly with the other individuals in your home.

If you’re experiencing any of the above-mentioned issues, don’t worry, there’s a way to fix it. You are probably just in need of a humidifier.

To avoid the adverse effects of either low or high humidity, you need to take certain measures. Installing a humidifier or a dehumidifier may help, but how do you know which one to get? Let’s figure out what suits your needs best.

What is the Difference Between a Humidifier and a Dehumidifier?

The major difference between a humidifier and a dehumidifier is that one adds moisture to the air and the other removes it. What you need will depend on what you wish to accomplish.

  • Humidifier: A humidifier adds moisture to the air by releasing water vapor into the surrounding area for added dampness.
  • Dehumidifier: A dehumidifier removes moisture from the air by condensing out the moisture through air conditioning.

Let’s get into more detailed specifications of these two options to help you decide which one best suits your needs.


The humidifier releases steam

Humidifiers introduce humidity into an area by adding moisture to the air. Humidifiers come in different models – namely evaporative models and ultrasonic models. The diffuser installed in a humidifier breaks water into fine droplets that are then released into the air.

Large centralized air conditioners in split or air conditioners installed in your home are also humidifiers. There are two main types of humidifiers, which we’ll discuss below. 

Cool Mist Humidifiers

Cool mist humidifiers often use ultrasonic technology and evaporators. 

An ultrasonic humidifier uses high-frequency ultrasonic waves that vibrate against the surface of the water. These vibrations range from 2MHz to 3MHz, which is enough for converting water molecules into fine droplets.

An evaporative humidifier blows air through a fan or sponge that is kept wet by rotating it in a water reservoir. The air causes evaporation which, in turn, produces humid air.

Warm Mist Humidifiers 

Warm mist humidifiers, commonly known as vaporizers or steam humidifiers, make use of steam that is cooled before it exits the humidifier through a tiny opening. This mode of humidifying requires a source of heat to turn the water into steam.

If we compare the two, the cool mist humidifier is the most common type of humidifier used in homes because they are safe and do not involve boiling water that may spill or cause burns. 

Warm mist humidifiers are also beneficial as inhalants and may help with asthma and allergy symptoms. Most nebulizers used at healthcare centers are evaporators.


Portable dehumidifier colect water from air

Dehumidifiers are devices that use the air conditioning method to reduce the level of humidity by removing water molecules from the air. It is beneficial to counteract health issues or to eliminate musty odors and prevent the growth of spores, mild dew, etc.

There are two common types of dehumidifiers, which are as follows:

Refrigerant Dehumidifier 

The refrigerant dehumidifier condenses moisture out of a room by drawing out damp air from its surroundings. The air is then passed through a cold evaporator coil to cool it. After the condensation process takes place, the molecules are collected from the cold coil and released into the air.

Desiccant Dehumidifier 

The desiccant dehumidifier works by passing damp air through a rotor. The rotor has materials that are desiccants that absorb moisture. 

When the water molecules are evaporated from the room air, dry air is collected from the outside. The water inside is removed by adding heat to channel the vaporized moisture outside the room.

Both types stated above are comfortable to use and promise a safe environment free from insects and other creatures. 

Dehumidifiers can also greatly increase the shelf life of books and prevent the destruction of wooden walls. So this may be your go-to option to have a comfortable, low humidity home.

Ideal Usage of Humidifiers

To figure out what is best suited to your needs, you need to analyze the weather status in your area. Humidifiers are used in drier regions and primarily during the non-monsoon period when precipitation levels are low.

Humidifiers are best suited in the winter months and can help control allergies and respiratory congestion, as well as keep the skin and throat adequately moist.

Dehumidifiers, on the other hand, are more effective during the monsoon season and summer months when the humidity is high and the air is warm. People residing in coastal areas can greatly benefit from dehumidifiers as well to keep out pests and molds.


You should now be able to fully identify what the difference is between a humidifier and a dehumidifier. 

If your area has high or low humidity, installing one of the two types of devices is crucial to maintaining optimal health and personal comfort. Pick your go-to device now for healthy living. 

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