Differences Between A Humidifier And Dehumidifier

Differences Between A Humidifier And Dehumidifier
Differences Between A Humidifier And Dehumidifier

A humidifier adds moisture into a room, while a dehumidifier removes moisture. The comparison table below lists features & benefits differences between a humidifier and a dehumidifier.

Both appliances support the objective of allowing you to breathe easier and live more comfortably.



For moist air conditions

For dry air conditions

Works when humidity is above 50%

Works when humidity is below 30%

Used primarily in summer 

Mainly used in winter

Helps reduce chest congestion, allergies, and asthma

Helps clear sinus congestion. Allows you to easier 

Water drains into a bucket or out a hose

Releases moisture into the air

Helps with water damage

Prevents dry air damage

Humidifiers and dehumidifiers work hand in hand. They both create ideal living conditions. The right humidity range makes your space comfortable. Too little moisture or too much moisture in the air can lead to health issues. You can protect yourself and your family from the hazards of uneven humidity. 

Consider a humidifier-dehumidifier combo unit.

The ideal relative humidity range describes the right amount of moisture in the air. The right amount of moisture means that we feel comfortable and are healthy. 

The ideal moisture range for health and comfort is between 30-50% humidity.

The benefits of ideal relative humidity include:

  • Soothing Skin
  • Keeping Food Fresh
  • Keeping Insects Away
  • Reducing Allergens
  • Preventing Asthma
  • Improving Immune Systems
Ideal Moisture In The Air
Ideal Moisture In The Air
What Is A Humidifier
What Is A Humidifier

What Is A Humidifier?

A humidifier adds moisture into a room. Humidifiers add moisture to the air to avoid dryness that can cause discomfort.

Humidifiers protect us from dry skin, bloody noses, sinus congestion, sore throats, and lips. Humidifiers also help relieve any of the effects caused by the flu or common cold.

Auto On Off Humidifier
Auto On Off Humidifier

A humidifier will work when the humidity is below 30%. The air will be too dry and needs moisture. The automatic humidifier will turn itself on and turn itself off according to the moisture in the air.

When the humidity level is between 30% – 50% you need to switch the humidifier off. The moisture in the air is in the ideal range.

Impact of humidifiers on health

It’s essential to know how to use a humidifier. Overusing a humidifier can aggravate respiratory issues. 

The most prevalent accidents associated with humidifiers are steam burns. If you have children, take special care. Never let kids touch humidifiers. Avoid putting warm-mist steamers where children can reach them.

Condensation on windows and walls can build-up when too much moisture has been added to the air. 

  • One consequence of too much moisture is that mold is encouraged to grow and spread. 
  • Dirty humidifiers can also cause bacterial growth that can promote coughs and colds.
  • Know that humidifiers can release minerals and microorganisms into the air. 

A small number of minerals in the air are not harmful, but they may bother people with asthma. To avoid this problem, use of distilled water in your dehumidifier. [1]

A humidifier creates pleasant living and working conditions. Humidifiers protect property from inadequate humidity.

Types Of Humidifiers
Types Of Humidifiers

Types Of Humidifiers

Central Humidifiers

Central humidifiers integrate into the air conditioning or heating unit of your house. They are my personal favorite. If you want to add humidity throughout the entire building, they’re the best option. 

Best of all, central humidifiers do not emit any steam. They are a safe option for children since there is no steam burn hazard.

Evaporator Humidifiers

Evaporators blow moisture via a moistened filter. Fans control the evaporator unit and spread the humidity further into the air.

Evaporative humidifiers tend to be smaller and therefore cheaper than central humidifiers. The downside is that evaporators only work in one room. Evaporators can blow too much moisture into the air as well. For people with asthma, this can be troublesome, as it increases the risk of mold development.

Impeller Humidifiers

Impeller humidifiers are effective. These units are less costly. Impeller humidifiers use spinning disks that operate at high speeds. They are also friendly to children because they produce cool mist and bring no chance of burns. 

Impeller humidifiers like evaporators only work in individual rooms. Again, if overused, impeller humidifiers can release too much moisture into the air, causing breathing issues for people with allergies and asthma.

Ultrasonic Humidifiers

Ultrasonic humidifiers work using sound vibration. You can’t hear the sound waves since they are above the upper limit of human hearing. Ultrasonic humidifiers create a mist. 

Ultrasonic humidifiers are available in both cool-mist humidifier and warm-mist humidifier versions. If you have children, an ultrasonic humidifier, with a cool-mist, is a good option.

Steam Humidifiers

Steam humidifiers are also referred to as steam vaporizers and warm-mist humidifiers. Water is heated. The resulting steam is how moisture is released into the air. Warm mist humidifiers can cause burns.[2] An advantage of steam humidifiers is that they are cheap and compact.

Signs you need a humidifier

  • Humidifiers are used when it is cold, between November to March 
  • You have dry, flaky skin and itchy scalp 
  • Your humidity level is below 30%
  • You have respiratory problems and asthma 
  • You use a furnace or space heaters in winter
  • You have wood furniture and floors that are drying out
Issue With Too Little Moisture In The Air
Issue With Too Little Moisture In The Air
What Is A Dehumidifier
What Is A Dehumidifier

What Is A Dehumidifier?

A dehumidifier removes moisture from a room. Dehumidifiers are used in basements, rooms, homes, garages, and office spaces. Dehumidifiers also work during water damage restoration. A dehumidifier creates pleasant living and working conditions. Dehumidifiers protect a property from the effects of excess humidity.

Remember the water cycle in science? Water evaporates, condenses, and then precipitates. The water cycle is always taking place in the air we breathe, even when we are indoors.

When indoor conditions lead to excess water vapor in a room, it leads to humid stodgy conditions. We need dehumidifiers to remove or cut the water vapor indoors. 

Auto On Off Dehumidifier
Auto On Off Dehumidifier

Your dehumidifier will run when the humidity level is above 50% until it reaches the desired relative humidity. This is usually between 30%-50%.

When the humidity level falls below 50% you need to switch the humidifier off. The moisture in the air is in the ideal range.

Impact of dehumidifiers on health

A dehumidifier can help relieve symptoms for those who have asthma or allergies. High humidity can lead to a variety of health issues.[3] Excessive moisture can lead to allergic reactions. Allergens cause wheezing, sneezing, chest pain, eye irritation, and itching. 

Dehumidifiers are made for various places and there are different types of dehumidifiers.

Using the correct dehumidifier can address your particular needs. I bought a small portable unit in the past and it was insufficient for my needs. Here is a dehumidifier size chart that may be of assistance.

The size or capacity of a dehumidifier you need depends on the size of the room and how much moisture is in the room. An easy dehumidifier calculator can guide you.

Types Of Dehumidifiers
Types Of Dehumidifiers

Types Of Dehumidifiers

Refrigerant Dehumidifiers

Refrigerant dehumidifiers remove moisture by cooling the air. A fan moves the air over a series of coils that cool the air. Water then condenses. Moisture is collected in a water storage tank or flows out via a drain hose. Then a fan blows back dry cooler air into the surrounding space.

Refrigerant dehumidifiers are also called evaporative dehumidifiers. Refrigerant dehumidifiers are the most common type and an efficient way to tackle humidity in temperate climates.

Some units have an air filter. The filter catches some contaminants like dust, dirt, and allergens in the air. Removing contaminants in the air is good for healthy living.

Absorption Dehumidifiers

Absorption dehumidifiers use a desiccant or chemical drying agent to remove moisture from the air. Instead of cooling the air, a chemical drying (or desiccant) agent extracts moisture. This agent, or desiccant, is on a heat exchange wheel. The wheel absorbs moisture from the air and drier air is returned. 

Absorption dehumidifiers are also called low-temperature dehumidifiers. If you live in a colder area a desiccant dehumidifier is right for you. 

A refrigeration-style dehumidifier won’t work well at low temperatures. When it gets cold, the coils of a refrigerant dehumidifier tend to ice up or freeze. The evaporative coils work ineffectively or stop working altogether. 

Portable Dehumidifiers

Portable dehumidifiers are lightweight, making it easy to move them from one room to another. Portable dehumidifiers from department stores tend to be smaller models suited to small rooms. 

Portable units are not as durable as whole-house dehumidifiers or dehumidifiers designed for specific locations.

Ionic Dehumidifiers

Ionic membrane dehumidifiers are a new alternative in the dehumidifying market. This new technology uses electrolysis to remove water vapor at a molecular level.

The attractive aspect of these ionic dehumidifier units is that there is no liquid water residue left behind. This means you do not have to throw out water that would have accumulated in the tank.

I like this unit because it requires no maintenance. It is quiet and vibration-free. Ionic dehumidifiers are compact and have an expected 3 to 5 year service life. 

Ionic membrane dehumidifiers have a wide operating thermal range. Ionic membrane dehumidifiers work at temperatures from -10 to 50°C (14 to 122°F) and can dry to under 10% RH; relative humidity when required.

Electronic Dehumidifiers

Electronic dehumidifiers use an electronic thermodynamic cooler (Peltier heat pump). Electronic dehumidifiers condense water vapor into moisture. 

With no moving parts, these units are reliable and silent. Electronic dehumidifiers are suitable for smaller areas and relatively moderate moisture conditions. [4]

Signs you need a dehumidifier

  • You have condensation on the windows and doors 
  • Musty odor
  • Mold spots developing on the walls or ceilings
  • Water runoff dampness during spring 
  • Peeling paint and paint that blisters 
  • Floors and doors that creak 
Issue With Too Much Moisture In The Air
Issue With Too Much Moisture In The Air

A humidifier-dehumidifier combo works best to maintain a balance.

  • The humidifier feature will turn on when the air is too dry below 30% relative humidity.
  • The dehumidifier feature will turn on when there is too much moisture in the air above 50% relative humidity.
Auto On Off Humidifier Dehumidifier Combo
Auto On Off Humidifier Dehumidifier Combo

Can You Use an Air Conditioner Instead of a Dehumidifier / Humidifier?

An air conditioner does dehumidify the air, but cooling air is the main function.

Using an air conditioner alone is insufficient to dehumidify a mid-sized room in a moist environment. 

Take a look at the air conditioner Area versus BTU (AC capacity) graph and table below. An air conditioner is designed to cool a room.

Using an air conditioner compliments a dehumidifier. Here is our favorite list of combination Air Conditioner – Dehumidifier appliances.

Area Vs BTU
Capacity NeededApproximate AreaCapacity NeededApproximate Area
(BTU Per Hour)(Square Feet)(BTU Per Hour)(Square Feet)
5,000 BTU20012,000 BTU500
6,000 BTU25013,000 BTU500
8,000 BTU32014,000 BTU600
8,500 BTU32015,000 BTU600
9,500 BTU40018,000 BTU800
10,000 BTU40022,000 BTU1000

A dehumidifier is designed to remove huge amounts of moisture from the air.

While a humidifier is designed to add lots of water to the air.

Here are recommendations on the best humidifiers – dehumidifier combo units

Final Thoughts

If you want to live comfortably then it’s important to live in an ideal humidity range. Make your space comfortable by buying an appliance today. 

A humidifier and a dehumidifier are both essential appliances to have. They each play an important role when it comes to humidity control. They also work well together, if you decide to get both. 

Get a humidifier-dehumidifier combo which is the best of both worlds. What size dehumidifier is right for you? Find out here.