How Does a Dehumidifier Work?

Men and women who live near a coastal region or in proximity to the equator are familiar with humidity. Every person, however, has likely encountered humidity at some point in their life. The heavy feeling of the air and muggy atmosphere are easy to identify, and the problem only becomes worse when it’s raining or hot outside. Frizzy hair, damp clothing, and more accompany high humidity levels, and it negatively impacts a person’s mood. 

When a person working in electrical services speaks of humidity, they actually refer to relative humidity. Air can only hold so much water, and the amount it contains depends on the air temperature. The ratio of vapor in the air to the fixed amount of water the air can hold is relative humidity. A person can determine how much relative humidity is present at any given time, but most men and women don’t need this information. They know they are uncomfortable and that’s what matters. 

Once humidity makes its way into the home, a person finds they cannot get comfortable regardless of what they do. The home feels stuffy and a musty smell often arises as a result. However, it comes with many dangers people may not be aware of. High humidity levels attract pests, can make the occupants of the home ill, and negatively impact the integrity of the structure. 

The ideal relative humidity for a home kept at 68 degrees Fahrenheit would be between 30 and 50 percent. When a homeowner finds it challenging to keep the residence at that level, it is time to look into obtaining a dehumidifier. A dehumidifier removes any excess moisture from the air. As a result, the occupants find they are more comfortable, and the home itself is protected. 

Before going to purchase this device, homeowners need to know what types are available and how to get the most out of this machine. In addition, it’s helpful to know how a dehumidifier works. 

How Dehumidifiers Operate

Set a cold drink outside for a few minutes and you’ll see the outside of the glass or can is wet. This moisture appears when condensation forms on the surface of an object. As the air cools, it cannot retain as much water. Objects that are colder than the air pull and collect water from the atmosphere, and this is the condensation seen on surfaces. Humidifiers work in much the same way. They pull and collect water from the air.

Dehumidifiers are made up of a few basic parts. The fan compressor cools coils in the dehumidifier by expanding and compressing a refrigerant gas such as Freon. The unit also contains a reservoir where water is collected and compressor cooling coils. Finally, these devices come with a reheater that is responsible for capturing and collecting the heat that is generated during the cooling process. 

These components work together to remove moisture from the air using a simple and effective process. The fan within the unit captures air around the unit and pulls it in. Once inside the unit, this air passes over the cooling coils in the compressor. The coils pull the moisture from this air in much the same way objects pull moisture from the air in nature. This moisture collects on the coils before dripping into the reservoir. Once the moisture has been removed, the unit reheats the air and sends it back into the environment. 

Most dehumidifiers come with a plastic bucket that serves as the reservoir. The person may dump this bucket manually or attach a hose to a fixture on the reservoir. With this method, the owner can drain the reservoir directly into a pump or floor drain. 

People often worry the reservoir may overflow when they aren’t home or if they forget to empty it. This need not be a concern, as these units come equipped with an automatic shut-off to prevent that from happening. Nevertheless, many people choose to purchase a dehumidifier with a built-in condensate pump.

This component removes water from the reservoir rather than waiting for gravity to empty the tank. Individuals who are dealing with extremely moist conditions and those who prefer to leave the unit running continuously should consider this option. 

Many units today come equipped with a humidistat so the user can set the unit for the desired level of relative humidity. This device comes with a sensing element and relay amplifier. These components ensure the home remains at a comfortable level for the occupants while keeping the structural integrity of the building safe. 

This explains the basic operation of dehumidifiers. However, these devices come in a few basic styles. Consumers must know these styles to determine which will be best for their home. In addition, they need to understand why a dehumidifier may be needed, especially in those homes with air conditioning, as AC units are designed to cool the air and reduce humidity at the same time. 

Understanding the Differences Between an Air Conditioner and a Dehumidifier

Air conditioners and dehumidifiers both work to reduce the humidity in the home. Air conditioning units pull warm air in from the atmosphere and cycle it over cold coils to remove any heat. Dehumidifiers do the same thing. However, air conditioning units don’t reheat the air before releasing it back into the atmosphere. This is how the air conditioner works to keep the space cool. Air conditioning units also lack a humidistat so the homeowner cannot control relative humidity using the AC.

Air conditioners stop running when the home reaches the set temperature, which may allow the humidity level to rise again. This leaves the home feeling hotter than it is. For these reasons, homes benefit from having both air conditioners and dehumidifiers in place. 

Dehumidifier Types

Many individuals know of refrigeration dehumidifiers but remain unaware of desiccant units that fulfill the same purpose. Both types help to keep an area nice and dry. Furthermore, they both pull air in from the atmosphere and remove any moisture. Where they differ is in how they accomplish this goal.

Desiccant materials like silica get naturally absorb moisture. This explains why many manufacturers place them in their packaging. There is no need for the desiccant dehumidifier to cool the air before removing the moisture, which is why this technology is best used in sub-zero conditions. 

As the technology behind dehumidifiers is very basic compared to many other household appliances, consumers find these units come in different sizes and strengths. Head to the local home improvement store and purchase a portable dehumidifier. These units are inexpensive, lightweight, and easy to use. Homeowners find them to be of great help in a bedroom, kitchen, or other restricted space. 

Restoration dehumidifiers, in contrast, are much larger machines. The heavy-duty units can be used in less-than-ideal conditions. For example, restoration dehumidifiers become of great help when a person is cleaning up from a natural disaster, such as a hurricane, that left behind significant water damage.  

Whole-house dehumidifiers work together with a home’s HVAC system. These units require the help of a professional to install. As there are different whole-house humidifiers for different purposes, a homeowner needs to speak with the installer to determine which best meets their needs. For instance, crawlspace humidifiers work to remove moisture from storage areas. The HVAC tech assists clients in determining which will help achieve their stated goals. 

For those who don’t have a dehumidifier and need to remove moisture from a small space, such as a closet, silica gel may be used. Home improvement and pet stores often carry this substance that absorbs moisture. People can reuse these crystals multiple times simply by heating the crystals in an oven or in bright sunlight. In fact, some manufacturers today sell products with color-changing properties. This lets the user know when the crystals must be heated to restore their effectiveness. 

The Cost of Using a Dehumidifier

Individuals may worry about the cost of operating a dehumidifier. Portable dehumidifiers can use more energy than the refrigerator in a home. Nevertheless, the device’s energy usage remains less than that seen with air conditioning units. As high relative humidity makes a home feel warmer than it is, a person might find that running the dehumidifier means they run the air conditioner less, saving them money without sacrificing comfort. 

Furthermore, users find they can maximize the efficiency of their dehumidifier. Don’t let the unit run continuously, and set the humidistat at 50 percent rather than 30 percent. Keep the doors and windows closed when running the dehumidifier, as these units aren’t designed to remove moisture from the outdoor air. 

Most units today allow the air to exit the unit at the top of the machine. If you have an older model, make certain it isn’t placed near walls or furniture to ensure the air can circulate freely. Keep the unit away from areas with excessive dust and debris so the machine doesn’t become clogged, and clean the filter regularly. As with an air conditioning unit, regular filter changes ensure optimal efficiency. 

To further reduce your carbon footprint and save energy, use the water collected by the dehumidifier rather than pouring it down a drain. This greywater cannot be consumed by humans but is perfect for watering plants because it contains less salt than tap water. Before using the greywater, however, make certain doing so is permitted in your area. 

Dehumidifiers do come with some drawbacks that potential buyers should know. Users need all information to determine whether this device will add value to their lives. The cost of purchasing a dehumidifier deters many from investing in a unit. In addition, some people don’t like the look of the machine in their home. They feel it detracts from the look and feel of the residence. Before spending the money to purchase a unit, determine whether one is truly needed. 

When is a Humidifier Needed? 

Individuals can determine whether they need a humidifier before making this investment. Condensation on windows suggests a unit should be purchased, and the same holds when a person spots wet stains on ceilings and walls. Mold and fungus growth in the home or wood that is rotting and weak suggests excess moisture is a problem in the residence while blistering paint or peeling wallpaper are signs a dehumidifier is needed. Finally, any residence that has a stuffy, musty atmosphere would benefit from this purchase. 

However, not all signs of excess moisture in the home are this obvious. Doors, cabinets, and windows that stick may be victims of excess moisture. Wood swells when it absorbs moisture, and floors begin to creak when this happens. The moisture pushes the joints apart, and this leads to screws and nails coming loose. The excess moisture must be removed to protect the home’s structural integrity. 

Air quality improves when humidity levels in the home remain at a reasonable level. Many people suffer from mold, fungus, and dust mite allergies. By controlling the relative humidity in the home, a person reduces the presence of these allergens in their residence. Mold can make humans ill and any moisture in the home leads to ideal conditions for mold growth. A dehumidifier removes the excess moisture to reduce the risk of mold in the home. 

Many pests prefer a moist environment, including roaches, spiders, and centipedes. Using a dehumidifier discourages pests from taking up residence in your house. A dehumidifier can also be of benefit to individuals suffering from a congested cough. These serve as only a few of many reasons why a person may wish to purchase one or more dehumidifiers for their residence. 

It’s always best to prevent excess moisture from building up in the home. Repair plumbing fixtures that leak, keep the gutters clear and patch any cracks in the home’s foundation. Use exhaust fans in the kitchen and bathroom to remove extra moisture. If you find this isn’t enough to solve the humidity issue in your home, it’s time to consider a dehumidifier. Fortunately, this is one purchase you won’t regret as these units are helpful in many ways.