How Do Dehumidifiers Work?


Dehumidifiers have become an integral part of many homes because they help to remove or reduce moisture and dampness. In this article, we will be taking a closer look at how dehumidifiers work and how they get rid of moisture in the air. 


How Does a Dehumidifier Work?

Most dehumidifiers work like air conditioners. They have a fan that draws in moist, warm air into the coils of the machine. The moist air crosses over the refrigerated coils of the device and the air condenses as moisture. The condensed moisture accumulates and falls into a storage tank. The machine then releases the remaining drier, cooler air back into the room.


Detailed Explanation of How Dehumidifiers Work

A dehumidifier works in two different ways – through refrigeration or adsorption/absorption. The process of refrigeration is similar to the technology air conditioners and refrigerators use – it cools and removes moisture in the air. The second process involves the absorption of moisture into a drying material. 


The Refrigeration Process

The refrigeration process is the most common, as the majority of dehumidifiers come with this technology. It works in a very simple way, which is as follows:

  • The machine has a grille on one side that sucks in moist, warm air. 
  • The moist, warm air is drawn inward by an electric fan. 
  • The moist air crosses over the refrigerant cold coils of the machine, through which a coolant circulates.
  • As the cold pipes cool the air, the moisture in it condenses and transforms back to liquid. The liquid, which is in little droplets, drips off the pipes into a storage tank dedicated to holding the water. 
  • When the air is free of moisture, it then passes over the compressor or condenser unit, which warms it back to its original temperature. 
  • After restoring it to its original temperature, the machine then blows back the dry, warm air into the room via a different grille. 
  • The moisture, which is converted into liquid drops into a bucket (or tray) at the bottom of the machine. The machine has a plastic float that rises as the water in the container increases. 
  • When the storage is full, the float will trigger an electric switch that will turn off the fan. It will also turn on an indicator light, which is a sign that you need to empty the machine. 


The Adsorption/Absorption Process

While the majority of dehumidifiers work by refrigeration, some models work by adsorption or absorption. In this process, the dehumidifier mops the water from the moist air with a material that holds water and then removes the water by squeezing it away. 

The mopping process involves adsorption or absorption. In the adsorption process, the moisture in the air is picked up on the surface of something while for that of absorption, it is soaked into something. Here is how this process works:

  • The machine draws moist air into the room via a duct. An electric motor-operated fan is responsible for drawing the moist air.  
  • The drawn air moves through a rotating wheel that removes the humidity. The rotating wheel is made of a material that can absorb water. 
  • Underneath the machine is an air duct, and it has an electric heating element that always keeps it hot. 
  • The rotating wheel rotates past the heated space and hot air blows it to dry it. 
  • The fan blows back dry air into the room. 
  • The machine then blows out wet, hot air via an exhaust duct. 

The entire process is very fast, and it is controlled by humidity sensors and thermostats. With the vast control it offers, you can make the room as dry or hot as you want.


How Can I Get the Most From My Dehumidifier?

Humidity indoors can be a major issue, especially in laundry rooms, basements, crawl spaces, and bathrooms. This is why dehumidifiers are very important in many homes, as they help to reduce or get rid of moisture in the air. 

However, for this machine to function at its best, you need to know how to use it properly. Dehumidifiers are not like some other electric appliances out there that you can buy and just leave them to be working on their own. You need to manage and monitor your device regularly for it to function optimally. 

If you want to get the most from your dehumidifier, there are certain things you need to do regularly. Here are some expert advice on making your dehumidifier function at its best:


Set the Optimal Humidity Level

According to Energy Star, the optimal level of humidity is between 30% and 50%. During heating seasons in colder areas, the optimal level is between 30% and 40%. Setting the humidity level too high can cause the formation of mildew, dust mites, and mold, and this can trigger allergies. If you want your machine to work at its best, then you should set it to the optimal humidity level. 


Position It Properly

For a dehumidifier to function optimally, you need to make sure it is at the right spot. You need to put it in the right spot to allow for adequate airflow. Air needs to flow in and out of the machine freely. There are different models of dehumidifiers, some vent air through the top while others vent through the side. 

You need to check the model you have and know where it releases air from. Regardless of where your machine vents air from, you should make sure it has enough space around it. It should not be too close to the wall, as that could restrict the airflow.


Empty the Water Storage Regularly

Emptying the water storage is one of the best ways to keep this machine functioning at its best. When the tank is full, the machine will shut off automatically. You will see an indicator reminding you that you need to empty the tank. 

To make sure the machine does not stop working when you are not in the house, you should empty the water storage/collector regularly. Some dehumidifiers make it possible to connect a hose to a drainage system, which would ease the stress of emptying the tank regularly.


Close Your Doors and Windows

If you want your dehumidifier to work more efficiently, you should close the doors and windows of the room you are using it in. Enclosing the space would help the device to work much faster and efficiently. 


Clean It Regularly

Cleaning your dehumidifier is one of the most important things you need to do if you want it to work optimally. One of the places to focus on when cleaning it is the filter, as it filters the air that enters the machine. When the filter is dirty, the dehumidifier will not function at its best. 

Fortunately, some models come with an indicator that will remind you when to clean the filter. When you want to clean it, remove it gently, wash it, and then dry it. You should clean it regularly. You can also see the manual for cleaning advice. 

Another part of the machine you should clean regularly is the grill. Airflow will be reduced when the grill is dirty. To prevent this, you need to clean it regularly. You should also clean the coils, as well as the water storage unit. 


Check for Frost

Unexpected temperature changes around this machine can have a negative impact on the way it functions. If you use your appliance in temperatures below 18-degree Celsius, frost can develop. If there is a buildup of ice or frost in your machine, and also on the filter and coils, move it to a place with a temperature that is high enough for the frost or ice to melt away. 


Uses and Health Benefits of Dehumidifiers 

Dehumidifiers have proven to be very useful and helpful since their emergence. This appliance comes in handy in many situations, and there are many health benefits to using it. Here are some of the benefits of using a dehumidifier.


It Helps to Create a Healthy Environment

One of the major benefits of a dehumidifier is that it helps to create a healthy environment. When you get rid of dust and mold in your house you are also eliminating invaders such as spiders, cockroaches, and other dangerous insects and pests. 

Reduced levels of humidity can also help those with COPD. Those who live in naturally humid climates would also greatly benefit from dehumidifiers, as they can cool off their homes and reduce the way they use their air conditioners.


It Can Reduce Symptoms of Allergy

Some of the symptoms caused by environmental allergens include sneezing, itching, eye irritation, chest pain, and wheezing. Things that could trigger allergies include pollen, dust mites, mold, and animal dander. Fortunately, reducing the level of humidity in your home can help to keep triggers at bay. 

With a humidity level of 65%, dust mites can survive and reproduce. You can use a dehumidifier to manage that level of humidity with ease. When you dehumidify the air, you will reduce the chances of mold growth in your house.


It Helps to Reduce Odors

There is a strong smell that accompanies the development of mildew and mold. Fortunately, dehumidifying the air in your home will help to reduce this odor. This device will help to eliminate that rotting or moist smell that comes with mildew or molds.


It Reduces Energy Costs

A dehumidifier can also help to reduce your energy bills, as it can make your air conditioning unit function more efficiently. If the humidity level in your house is very high, your air conditioner would have to do more work to cool the air and get rid of moisture. This additional work would only result in an increase in your electricity bills. 

In addition to increasing your energy costs, it would reduce the lifespan of your air conditioner, which is something you do not want. Hence, using a dehumidifier will help to reduce the humidity level in your house, which means your air-conditioning system would have less work to do.


Enhances Comfort

A house is more comfortable when it has the optimal level of humidity. Dehumidifiers help to enhance the air quality in the house. It keeps the air cooler and makes the house more comfortable.

If there is a lot of moisture in the air, it would make the stuffy and less comfortable. High levels of humidity also cause an unpleasant smell, which would cause discomfort in the room.


How Do I Know If My Home Needs a Dehumidifier

Dehumidifiers do not only defend against high levels of humidity; they also make the home safe and comfortable. Hence, how do you know when you need a dehumidifier in your house? Here are some common signs that your home needs a dehumidifier. 


Condensation on Your Window and Patio Doors

When you start noticing water dripping on your window, condensation on your interior glass, or something that looks like vapor or fog on your glass, it is a sign that the moisture level in your room is very high. 

If moisture builds up on the windowsill, it can cause the wooden casing to rot, and this will promote the growth of mold in your home. If you see dark or black grunge at the bottom window trim, it is a sign of mold. You are likely to experience this if your humidifier is larger than your room. 

Once you notice an increase in moisture level in your home, it is a sign that you need a dehumidifier. This device will help to reduce or eliminate moisture in your home, making it more cozy and habitable. You should take note of the places affected by excess humidity and rotate the appliance through those places.


A Damp Basement

In most houses, it is usually the basement that suffers the most from high levels of humidity. Is the humidity level in your base always higher than in other parts of the house? Does it feel damp whenever you go down there? If you have been noticing all these without any water leakage, then your home would benefit from dehumidifier usage. 

Even when you have an HVAC or central air-conditioning unit, you might still experience this issue. During the humid and hot summer seasons, your air conditioner might have issues recirculating dry, cool air to the basement. This can result in increased levels of humidity in the basement, which might later affect your home.


Mold Spots on Wall Corners and Ceilings

Steam from the shower rises and settles on the edges of the walls or ceiling of the bathroom most times. They form mold spots on the wall edges or ceiling because there is no efficient fan in the bathroom to divert humidity and steam to the outdoors. 

Mold can grow in different parts of the bathroom including the ceiling, wall, shower surround, around or beneath the toilet, and beside the bath. If shower steam is the cause of the humidity, then running a dehumidifier can help resolve the issues. 

A plumbing issue or leak toilet can also result in moisture problems. While you use a dehumidifier to reduce the moisture, you should look for the root cause of the problem and resolve it. This appliance will help to reduce the moisture level and damage, but you should not ignore the cause. 


Stale Smell

The presence of a stale smell or door in certain parts of your home that do not receive enough vent, such as the garage, crawl space, and the basement is an indicator that there is mildew and mold in your home. You can use a dehumidifier to get rid of this smell or odor.


Creaky Windows, Cabinets, Floors, or Doors

When excess moisture penetrates your cabinets, windows, doors, and floors, the wood will start expanding and lose its joints, nails, and screws. Fixing these components and dealing with the moisture that caused the damage will not resolve the issue. You need a dehumidifier to help reduce or eliminate the moisture in your home to prevent such damages. 


Things to Consider When Looking for the Best Dehumidifier 

If you are looking for the best dehumidifier, there are some vital things you need to put into consideration. There are different types of dehumidifiers on the market from different manufacturers, and you need to pick the right one that would be ideal for your room. Here’s what to look for.


Pint Capacity

This refers to the amount of moisture that the machine can eliminate in the environment within 24 hours. If you have a large home that is up to 3,000 square feet, you should choose an option with a pint capacity of 70 or less. If the room is smaller, you should opt for a lower capacity. 


Collection Tank Size

Some dehumidifiers allow you to connect a hose to a drainage system. This eliminates the need to be emptying the tank frequently. However, those options are on the higher end of the price spectrum. If you want to opt for a model that uses a collection tank, then you should consider the size of the tank. 

You should opt for models with larger tank capacity. If the tank is small, you would need to be emptying it frequently. The larger the capacity of the bucket, the better. 


Low-Temperature Option

If you want to use this appliance in non-insulated places like the attics or basement, then you should buy a model with low-temperature options. With this feature, the dehumidifier can work in temperatures as low as 30 degrees Fahrenheit. 



Dehumidifiers play a key role in many homes today. They help to enhance indoor air quality, which helps to make the environment friendlier and healthier. However, knowing this appliance works, when you need it, how to take care of it, as well as how to buy the right one for your home is very important.