How Dehumidifier Work?

As a homeowner, I have often faced the challenge of dealing with excessive moisture and humidity levels in my home. When it got really bad, I decided to invest in a dehumidifier, hoping that it could help improve the air quality and comfort inside my house.

How Dehumidifier work simple “By removing excess moisture from the air, creating a more comfortable and breathable environment for us to live in”.

How Dehumidifier Work

In this blog post, I’ll explain in detail how dehumidifiers work and how you can use one to improve the atmosphere inside your home.

What is Dehumidifier?

A dehumidifier is an appliance that helps reduce the amount of humidity in an indoor space. This helpful machine can regulate and maintain a suitable level of humidity in your home, office or industrial building. 

By absorbing moisture from the air, a dehumidifier reduces dampness to create a comfortable living environment free from allergens, unpleasant odors and potential health risks associated with high levels of humidity. 

This small but mighty device functions by pulling warm air into its system. The air passes through a cold coil which causes the water vapor to condense out of the air and collect in a tank inside the machine. 

The now-dryer air is then dispersed back into your room via an exhaust fan leaving you with fresh, clean air. The ability to efficiently keep the humidity at a comfortable level makes dehumidifiers a great choice for households with allergies, asthma and other respiratory conditions.

How Dehumidifier Work?

A dehumidifier is an electrical appliance that reduces the amount of humidity in a space. It works by drawing in moist air, reducing its relative humidity, and then releasing the dry air back into the room or home.

At the heart of a dehumidifier is a fan that draws in air from a humid environment such as a living room or bedroom. The air passes through an evaporator coil where it is cooled below its dew point, causing condensation to form on the surface of the coil. 

How does a dehumidifier work

This condensed moisture is collected in a container or drained away via a hose connected to the unit. The now-drier air exits from another side of the system and returns to your living space. Because it is at a lower humidity level than when it entered the dehumidifier, you’ll notice that the air feels cooler and more comfortable.

The dehumidification process helps to reduce mold growth, keep allergens such as dust mites to a minimum, and control odors caused by dampness in your home. It is an ideal appliance for anyone living in a humid area or who has an issue with excess moisture indoors.

The step that take humidifier to perform its task:

  1. Air is drawn into the unit by a fan
  2. The air passes over the cooled coils, resulting in its moisture condensing
  3. Water falls into the drip pan or removable bucket
  4. The air is reheated by the heat recovery system
  5. Reheated and much dryer air disperses back into the room
  6. An automatic defrosting system de-ices as necessary
  7. When humidity reaches desired levels, it will turn off automatically until levels rise again for operation to resume.

Dehumidifiers are an essential tool for reducing indoor humidity and controlling mold growth in your home or office space; thus ensuring that you have comfortable and healthy living conditions throughout the year.

Types of Dehumidifiers and How they work:

There are two types of dehumidifiers available in the market both perform same task but with different method:

  • How Desiccant dehumidifier work?
  • How Refrigerant dehumidifier work?
  • How whole-House dehumidifier work?

1. How Desiccant Dehumidifier work?

A desiccant dehumidifier is a type of dehumidifier that uses a special material called a “desiccant” to absorb moisture from the air. Desiccants are substances that have an affinity for water and can absorb it from the air into its own structure.

The desiccant in a dehumidifier is usually a kind of silica gel or zeolite. Desiccant dehumidifiers are particularly effective at removing moisture from the air in cooler temperatures and areas with high humidity.

This makes them an ideal choice for basements, garages, warehouses, and other humid spaces. Unlike their refrigerant-based counterparts, desiccant dehumidifiers do not require electricity to work so they can be used in off-grid locations where electricity is scarce.

Working principle of dehumidifier

Desiccants work by absorbing the moisture from the air through a process called adsorption. When the desiccant comes into contact with moist air, it attracts water molecules as if it had tiny magnets inside. As the desiccant absorbs more and more moisture, it becomes saturated and needs to be dried or replaced.

Once dry, the desiccant can be reused over and over again without needing to be replaced or replenished. This makes desiccants an economical choice for dehumidifying your home or office space as they are often cheaper than other types of dehumidifiers in the long run.

Desiccant dehumidifiers are also quieter than their refrigerant-based counterparts, making them an ideal choice for areas where noise is a concern such as bedrooms or living rooms.

2. How Refrigerant Dehumidifier work?

A dehumidifier draws warm and moist air into the machine while cooling it down with refrigerant-cooled coils. This process causes the moisture to condense on the coils within the dehumidifier.

The refrigerant coils of a dehumidifier are colder than the air passing through them just like a glass of ice water. As the air cools, its ability to retain moisture reduces and when there is more moisture than it can hold then form condensation occurs.

The cooled air then passes over a warm motor of the dehumidifier to slightly heat it up before it is discharged into the room. This warm and dry air then attracts surrounding moisture-rich air, thus continuously maximizing the efficiency of the dehumidifier.

Refrigerant dehumidifier working principle

Most dehumidifiers come with a removable bucket or pan that collects condensed water for easy disposal. Smaller single room dehumidifiers usually have this feature while larger space ones like Basement, Crawlspace and Restoration dehumidifiers come with built-in pumps for continuous drainage.

The Fral FDK54 Dehumidifier is an ideal example for large space usage in homes or businesses as it can cover up to 2,500 square feet area with its compact size and powerful nature. 

It also has added features like a digital humidistat and display, low-temperature operation down to 33°F, automatic hot gas defrosting system, etc.

3. How Whole-house Dehumidifiers Work?

Whole-house dehumidifiers are designed to work with your home’s existing heating and cooling system. The unit draws the warm, moist air from your home and cools it down so that moisture will condense into small droplets of water. These droplets of water fall into a collection pan or can be drained directly away from the unit. After the air has been dehumidified, it is then passed over warm coils and heated to the desired temperature for your home.

Whole-House dehumidifier working principle.

Not only are whole-house dehumidifiers a great solution for moisture control but they can also be installed in new or existing homes – this means that you can get the humidity levels under control without having to buy a separate unit for each room of your home.

How Long Does It Take For a Dehumidifier to Work?

Dehumidifiers can start working to reduce the humidity in your home as soon as you turn it on. However, due to the slow and gradual nature of the process, it often takes around 10 hours for a dehumidifier to bring down relative humidity levels within recommended limits. You might not observe any significant difference in the air quality for the first few hours after the dehumidifier is activated, as it works slowly and steadily over time.

The rate at which your dehumidifier will reduce humidity levels in your home can be adjusted according to your preferences. If you increase the speed level on your dehumidifier, then it may take anywhere from 8-12 hours for the humidity levels to be reduced effectively. So, if you want to get the most out of your dehumidifier, it is best to give it a few hours to kick in and start doing its job properly. This will ensure that your home stays moisture-free and comfortable for as long as possible!

How to tell if dehumidifier is working?

When wondering if your dehumidifier is working, there are several ways to tell. The most effective way is purchasing a hygrometer.

With this device you can measure the humidity levels before and after turning on the machine. It’s also helpful for monitoring how much of a difference it makes hourly – allowing you to get insight into its efficiency.

How to tell if dehumidifier is working

Another great way to make sure your dehumidifier is working properly is by manually checking the humidity levels in your home. Taking regular measurements can give you a clear overview of how much the air is drying out.

By keeping an eye on the amount of moisture in your home, you’ll quickly understand if it’s time to replace or repair your unit. This can help you to stay on top of your dehumidifier’s maintenance and ensure it’s working as well as possible for a long time to come. 

How does a dehumidifier work to dry clothes?

Using a dehumidifier for drying clothes is simple and effective. By removing excess moisture from the air, a dehumidifier can help you get that perfect dryness level in your laundry room and keep your clothes clean and crisp. The way it works is quite simple:

When you switch on your dehumidifier, it draws in warm, moist air and passes it through an evaporator coil. This cools the air and causes condensation to form on the coil. The condensation collects into a bucket or tray, removing excess moisture from the air.

The dryer air is then pushed back out into your laundry room, causing your clothes to be dried quickly and efficiently without having to resort to using a traditional clothes dryer. 

How does a dehumidifier work in a basement?

A dehumidifier is an important appliance for keeping a basement dry and free from excess humidity. Its primary function is to reduce the level of moisture in the air by extracting water vapor from it, and then releasing it back into the atmosphere outside. This helps keep mold growth at bay, as well as preventing musty odors and condensation from forming on walls and windows.

Basement dehumidifier working principle

The way a dehumidifier works is relatively simple. It draws in air from the basement, where it passes through an evaporator coil. The coil cools down the air, which causes moisture to condense onto it as droplets of water. 

This extracted moisture is then collected into a container or tank within the appliance, while the now-drier air is passed over a heating coil and returned back into the basement.

Benefits of Using a Dehumidifier:

Some health benefit of using dehumidifier are as follow:


Mold is a type of fungus that thrives in warm, damp environments. If left unchecked, mold can cause serious health issues including respiratory problems and skin irritation. A dehumidifier can help by reducing the amount of moisture present in your home or office and providing an environment where mold cannot survive.

reduce Mold by dehumidifier

Dust mites:

Dust mites are tiny insects that feed on dead skin cells and dust. They can cause allergic reactions such as sneezing, itchy eyes, and coughing. A dehumidifier works by reducing the amount of moisture in the air, making it difficult for dust mites to survive. By running a dehumidifier regularly, you can help to reduce the number of dust mites in your home or office and create a more comfortable environment.


reducing Pollen mites through dehumidifier

Pollen is a fine powder released by plants into the air that can cause hay fever, sneezing, and itchy eyes. A dehumidifier can help reduce the amount of pollen in your home or office by reducing the amount of moisture in the air. This prevents pollen from sticking to surfaces and reduces its overall presence in the environment.

Animal dander:

Animal dander is a collection of microscopic particles that come from pet fur and skin. It can cause sneezing, coughing, and other allergic reactions. A dehumidifier works by reducing the amount of moisture in the air and making it difficult for animal dander to remain airborne. By running a dehumidifier regularly, you can help reduce the number of allergens in your home or office and create a more comfortable environment.

reducing Animal Dander by dehumidifier


Using a dehumidifier can be a great way to reduce moisture in your home or office. From enhancing indoor air quality to reducing allergy symptoms, the health benefits of using a dehumidifier are numerous. So if you’re looking for an effective and efficient way to improve your indoor air quality, investing in a dehumidifier might just be the perfect solution! With its quiet operation and convenience, it is definitely an ideal choice for any home or business!

Related F.A.Qs:

How does a dehumidifier dry a room?

A dehumidifier works by drawing in moist air and releasing warm, dry air. As the humid air passes through the dehumidifier it is cooled, which causes the moisture to condense on cold evaporator coils. The condensed water is then collected into a bucket or pumped away. This process removes moisture from the air and helps to keep your room dry.

How often should I empty my dehumidifier’s water tank?

It depends on how much humidity is present in your home or office and how often you use the dehumidifier. Generally speaking, you should empty out the water tank once it reaches capacity (usually around 32 ounces).

Can I sleep in a room with a dehumidifier?

Yes, you can sleep in a room with a dehumidifier. Dehumidifiers are designed to operate quietly and shouldn’t disturb your sleep. In fact, running a dehumidifier at night can help reduce allergens like dust mites and pollen that can trigger allergic reactions while sleeping.

Where is the best place to put dehumidifier?

The best place to put a dehumidifier is in the room or area of your home that has the highest relative humidity level. Generally, this would be bedrooms, bathrooms and other areas of the home where moisture is more likely to accumulate.

Is there a better option than using a dehumidifier?

Using an air conditioner can be an effective alternative to using a dehumidifier, especially if you live in a hot climate. An air conditioner will cool down your space while also removing excess moisture from the air.

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