Many homeowners turn on their dehumidifier in the summer when the house gets too hot and sticky.
But as anyone familiar with these gadgets will agree, it’s odd to expect them to help with temperature regulation since they aren’t designed to function as AC units.
So, do dehumidifiers do anything to cool down a room?
This article will discuss how dehumidifiers work and how they affect room temperature by lowering the relative humidity. We’ll also cover how to use these devices effectively to prevent your home from water damage.
So let’s get started!
Do Dehumidifiers Cool the Room, Too?
Dehumidifiers don’t cool down a room in the traditional sense. However, they can make a room feel colder by lowering the relative humidity, which makes it easier for your body to cool down. Lower relative humidity makes it easier for sweat to evaporate off the skin to cool down your body.
How Dehumidifiers Work
Dehumidifiers work to maintain an ideal humidity in your house. Their primary purpose is to eliminate excessive moisture from the air to maintain the perfect indoor humidity, which ranges from 30-50%.
Dehumidifiers use a dehumidistat to detect when there is too much humidity. When this happens, the unit powers on automatically to eradicate the excessive moisture.
Let’s take a quick look at their components to understand better how these gadgets work.
Components of Dehumidifiers
Dehumidifiers are made of the following components, including:
- Fan compressor
- Reheater
- Refrigerant or desiccant
- Collection tank or tray
These components play different roles in the dehumidifier for efficiency, as discussed below.
Fan Compressor
The fan compressor is responsible for drawing in air from the room. It works by compressing and expanding a refrigerant gas such as freon. This process is necessary to cool the dehumidifier coils, which the air passes over to remove moisture.
The fan collects moist air from the room and passes it over the coils. Next, the refrigerant in the coils cools and condenses the water vapor in the air. Finally, the water droplets are collected in a tray or tank below the dehumidifier.
Reheater
The reheater is a component that aids in maintaining a consistent temperature within the dehumidifier. It helps warm air that has been cooled and condensed by the dehumidifier. This feature is crucial as it prevents water condensation on surfaces such as windows in your home.
The reheater collects the heat generated by the cooling process and uses it to warm the air before it is released into the room. This characteristic maintains a consistent temperature and prevents water droplets from forming on surfaces.
Refrigerant or Desiccant
Dehumidifiers use either a refrigerant or desiccant to remove moisture from the air. These components ensure the air from the dehumidifier is void of moisture that can cause water damage or mold in the home.
Refrigerants and desiccants work similarly. These chemicals are used in dehumidifiers to cool the coils that the air is passed over. The cooled coils condense the water vapor in the air, and the water is then collected in a tank or tray.
Collection Tank or Tray
The collection tank or tray is where the water condensed by the dehumidifier is collected. This component is essential as it prevents the water from overflowing and causing damage to your home.
The collection tank or tray is usually located at the bottom of the dehumidifier. It is made of plastic or metal and has a capacity of around 10 to 20 liters (2.64 to 5.28 gallons). It would be best if you regularly emptied the tank or tray to prevent your unit from overflowing.
Dehumidifier Types
There are three main types of dehumidifiers:
- Refrigerant
- Desiccant
- Whole-house ventilation dehumidifiers
Let’s look at each style so you can understand how they work.
Refrigerant Dehumidifiers
These dehumidifiers work like a fridge or freezer. They use a refrigerant, mostly R410A, to cool a metal plate over which air is passed. The water vapor in the air passing over the metal plate condenses, and water droplets are collected in a bucket below the unit.
The refrigerant used in these dehumidifiers helps cool and remove moisture from the air. This process happens continually until the desired humidity level is achieved.
A fan in the dehumidifier constantly draws in air from the room and pushes it over the metal plate mentioned above. These fans will not stop working until your room attains the set relative humidity.
It’s worth noting that these dehumidifiers are effective at room temperatures (60-70°F or 15.56-21.11°C). These gadgets are ineffective in extremely cold conditions as they can form ice on the metal coils. In most cases, ice forms on these plates in temperatures below 64.4°F (18°C).
If you live in a frigid region, you’ll have to invest in a refrigerant dehumidifier with higher-performing components. However, such dehumidifiers are costly as they have additional features to prevent freezing on the plates.
Desiccant Dehumidifiers
This variety uses a desiccant, a hygroscopic substance that absorbs moisture from the air. The most common desiccants are silica gel and calcium chloride.
A fan in the unit constantly draws in room air. The air passes over a wheel coated with the desiccant material. The desiccant absorbs the moisture in the air, and dry air is then passed back into the room.
The absorbed moisture condenses, and the water is drained into a tank or removed through a tube. Drawing in moist air, passing it over the wheel, and releasing dry air happens continually until your room reaches the set relative humidity.
The main advantage of these units is that they can work even in extremely cold areas. However, you should be ready to pay more energy bills. These dehumidifiers consume between 600-800 watts of electricity per hour.
Whole-House Ventilation Dehumidifiers
This type is installed in your ductwork and work with your HVAC system. They have a dehumidistat that monitors the relative humidity in your house. When it exceeds the set point, these dehumidifiers power on to remove the excessive moisture.
The dehumidifier has a blower that pulls in outside air and forces it into the house through the ductwork. Next, the air passes over coils that are cooled by refrigerant. Finally, the passing air condenses into water, which is drained into a tank or removed through a tube.
These systems are excellent if you want to dehumidify your entire house. However, they are expensive, and you’ll need to hire a professional to install them.
Do Dehumidifiers Affect Room Temperature? What Science Has to Say
The sole purpose of dehumidifiers is to stabilize the relative indoor humidity to get to the 30-50% range. But in doing so, dehumidifiers lower the room temperature, albeit by a smaller margin (and indirectly) than an AC unit.
To understand precisely how this happens, you need to know one baseline fact about humidity—excessive humidity causes muggy and clammy air, leaving the indoor environment feeling hotter to you than it might actually be.
So when we talk about a dehumidifier cooling down a room, the cooling effect isn’t concerning the temperature readings on a thermometer; it has more to do with how warm the indoor environment feels than how hot it actually is (if you were to measure it with a thermometer).
With that bit of clarification out of the way, let’s tackle the actual question: Why does a dehumidifier make a room feel colder to the people in it?
It all comes down to the rate at which sweat evaporates from your skin at different humidity levels. The more humid the air around you, the slower sweat evaporates from your skin.
So in high relative humidity, your body’s primary thermoregulation mechanism (i.e., sweat evaporating from your skin to lower your body temperature) is compromised. This makes you feel warmer because your body isn’t losing heat as efficiently as it could in lower humidity.
Running a dehumidifier has the opposite effect on how warm you feel in your home. It lowers the relative humidity, allowing sweat to evaporate off your skin faster to cool your body. The net effect of this is a room that feels colder, but a thermometer might not necessarily agree with what your senses tell you.
Note that a dehumidifier’s cooling effect is a byproduct of the dehumidification process and might not suffice in scorching temperatures.
Dehumidifiers are not designed to cool a room. So while they might make your home feel colder and more comfortable in moderate conditions, they’re better off complimented by an AC unit when it’s sweltering.
Dehumidification Benefits
According to the National Asthma Council, maintaining an ideal indoor humidity prevents your family from asthma, allergy, molds, and dust mites.
Let’s take a closer look at some of the issues dehumidification can help prevent.
Mite Allergen Reduction
According to the National Library of Medicine, excessive air humidity creates a conducive environment for dust mites to survive. These mites are the most common household allergens that expose families to asthma attacks and other respiratory problems.
Dehumidifiers lower the humidity in the air, making it inhabitable for dust mites. Removing these allergens from your home creates a safe environment for your family, especially those with asthma and allergies.
Mold Growth Reduction
High relative humidity is one of the leading causes of mold growth in homes.
Mold produces spores that are harmful to human health and can cause respiratory problems such as:
- Runny nose
- Watery eyes
- Itching
- Sneezing
- Coughing
- Difficulty breathing
- Headache
Dehumidification lowers your home’s relative humidity, making it impossible for molds to grow. Using one prevents the growth of mildew and your family’s exposure to mold spores.
Healthier Skin
Too much or extremely low humidity is unsuitable for your skin. Extremely low humidity makes the skin dry and rough, while high humidity exposes the skin to rashes and acne.
Dehumidification helps maintain the optimum humidity level in your home, which is essential for healthy skin.
Eliminating of Bad Odors
High relative humidity creates a conducive environment for the growth of bacteria and other microorganisms. Unfortunately, these microorganisms produce foul odors that can make your home smell unpleasant.
Dehumidifiers lower the relative humidity in your home, making it inhabitable for these microorganisms. They also come with filters that help eliminate foul odors, so you can rely on these gadgets to make your home fresh and welcoming for guests.
Final Thoughts
Dehumidifiers eliminate excessive humidity from your home using a refrigerant or desiccant. Unfortunately, these gadgets will not cool your house because they do not have an evaporator coil.
However, they will make your home more comfortable by eliminating mold, dust mites, and odors.
They also make your indoor environment feel colder than it might be by lowering the relative humidity, allowing your body’s natural cooling mechanism to function more efficiently.
Sources
- National Asthma Council: Indoor Humidity and Your Family’s Health
- Vivint: What’s the Ideal Room Temperature for Comfortable Living?
- Science Direct: Desiccant
- National Library of Medicine: Reducing relative Humidity Is a Practical Way to Control Dust Mites and their Allergen in Homes in Temperate Climates
- State of Rhode Island: Mold Health Risks
