Dehumidifiers reduce moisture content by condensing and removing the water molecules from the air in our homes. There are several types of dehumidifiers, and some can use refrigerants.
Compressor (or ‘Refrigerant’) and whole-house dehumidifiers contain refrigerants to facilitate dehumidification. The refrigerant absorbs the heat from humid air, enabling the water vapors to condense and collect in the dehumidifier. Desiccant dehumidifiers use an absorbent media and do not contain refrigerant.
In this post, we talk in great detail about refrigerants, their types, their health effects, and their use in dehumidifiers. We then elaborate on different types of dehumidifiers and which ones contain refrigerants.
What is a Refrigerant?
Refrigerant is a fluid used in cooling systems and dehumidifiers. They have a low boiling point, that allows them to absorb heat and readily convert it into vapors (gas).
It is often confused with coolants, but these chemicals are entirely different. While a coolant is primarily an anti-freeze, essential to prevent engine damage in cars, a refrigerant is used to absorb heat in dehumidifiers, air conditioners, HVACs and other appliances.
In fact, while a refrigerant has a low boiling point (boils at low temperatures), coolants are used to raise the boiling point (and lower the freezing point) of liquids.
Why is Refrigerant Used In Dehumidifiers?
Refrigerants are used in compressor and whole-house dehumidifiers and are crucial to dehumidification.
These dehumidifiers have cooling coils that contain refrigerant. The refrigerant causes the water molecules in humid air to condense when it comes in contact with them. This water is then collected in the dehumidifier (and removed from the air).
Note: desiccant dehumidifiers do not use refrigerants.
Types of Refrigerants
There are several types of refrigerants that are used in dehumidifiers. Some are only found in older models, while others are still used in modern dehumidifiers:
- Chlorofluorocarbon (CFC or Freon): Chlorofluorocarbons are commonly known as Freon. They have a high affinity for heat that makes them highly-effective refrigerants. However, more than 197 countries have banned their production for their ability to deplete the ozone layer. The ban also came into effect because the gas excessively contributes to global warming. Research suggests, one molecule of CFC has a greenhouse effect equivalent to 10,000 carbon dioxide molecules.
- Fluorocarbon (FC): Chlorine is the toxic substance in CFCs that harms the ozone layer. However, FCs do not contain chlorine, and don’t threaten the protective ozone layer. Unfortunately, they can form harmful compounds that may accumulate in the environment, meaning FCs have a high global warming potential.
- Hydrochlorofluorocarbon (HCFC): HCFCs have low ODP (ozone depletion potential) and GWP (global warming potential) in comparison to CFCs. This is because they are unstable and break down easily in the atmosphere. However, they contain chlorine and are thus still a potential threat to ozone. The production and use of HCFC’s are currently being phased out across the U.S.
- Hydrofluorocarbon (HFC or Puron): HFCs have no chlorine and hence zero ODP. Because of this, they were used as an alternative to HCFCs when the latter got banned. Their GWP is 1000 times more than carbon dioxide. They are also less efficient than other refrigerants and are therefore not used widely.
- Hydrocarbon (HC): HCs are different from other refrigerants we’ve discussed till now. They have zero ODP and extremely low GWP, i.e., <5. This makes them one of the most economical and eco-friendly refrigerant chemicals. Their high efficiency is owed to the high latent heat of evaporation, which is why some companies use HCs as refrigerants in domestic appliances.
- Carbon dioxide: Carbon dioxide is a natural refrigerant. It has zero ODP and 1 GWP when used as a refrigerant. However, it has a high inherent working pressure, which is not very compatible with the components of modern appliances.
Function of Refrigerant in Dehumidifiers
Irrespective of the type of refrigerant used, it is sealed within the cooling coil of a dehumidifier and serves two purposes:
1. Absorbing Moisture
As the air flows into the system, the refrigerant absorbs the heat and moisture from the air and converts it into a gaseous state.
When the hot and humid gas encounters the cooling coil, the temperature difference leads to an energy transfer between the gas and the coil. This eventually leads to moisture condensation (water vapors changing to liquid water), which is removed from the air.
2. Maintaining the Temperature of Cooling Coil
Refrigerant is capable of quickly alternating between expanded and contracted states. The fan compressor of a dehumidifier maintains this pressure change. The rapid switch in pressure lets the refrigerant absorb and release heat, which keeps the coil cool.
A significant temperature difference between the environment and the coil is crucial for the dehumidifier to work correctly. Ideally, there should be a 15 to 25°F difference between the incoming air and the coil for the moisture to condense.
Without refrigerant, it would be impossible to keep the coil cool, and the dehumidification system would be useless.
Types Of Dehumidifiers
In general, the basic working of all dehumidifiers is the same – air is drawn into the system, the unit retracts enough moisture from it to reduce relative humidity to the set level, and the dry air is then emitted into the room.
However, the mechanism of water extraction and absorption varies for the three types of dehumidification, i.e., compressor, desiccant, and whole-house dehumidifiers.
1. Compressor (Refrigerant) Dehumidifier
Compressor dehumidifiers are the typical dehumidifiers that use refrigerants for dehumidification. They have four main components; a refrigerant, fan compressor, cooling coils, and reheater.
- Once the humid air is drawn into the system via a rotating fan or natural circulation, it comes in contact with the refrigerant.
- The liquid refrigerant absorbs hot air and carries it to the cooling coils. In the process, the refrigerant changes its state from liquid to vapor and then to liquid again (when it releases the air).
- Upon contact with the cooling coils, the moisture in the air condenses and forms water droplets.
- This water is collected in a reservoir.
- As the dehumidified, cold air moves forward, it is reheated by the heating coils (the heat removed initially is added back into the original air stream).
- Finally, the dehumidified air is emitted into the room.
The unit is called a compressor dehumidifier because of an integral component called a fan compressor. This compressor alternately expands and compresses the refrigerant, making the heat transfer and condensation possible.
2. Desiccant Dehumidifier
Unlike compressor dehumidifiers that involve a complicated system of coils, compressor, and refrigerant, desiccant dehumidifiers use moisture absorbing material like silica gel to dehumidify the air (i.e., they do not use refrigerant).
They have a rotating wheel consisting of multiple grooves and a desiccant substance like silica gel. As the wheel rotates, the surrounding air passes through it, and the silica gel absorbs the moisture from the air.
Interestingly, 75% of the air that passes through the wheel is dehumidified and then sent to the central system before being emitted as dry, warm air. This is called process air.
On the other hand, 25% of the original air stream is utilized as reactivation air. This air is reheated upon entering the central system. Then, it passes through the corrugated wheel in the opposite direction as the process air.
This way, the reactivation air extracts moisture from the silica gel, preparing it to absorb humidity again in the following dehumidification cycle.
Whole House Dehumidifier
Like compressor dehumidifiers, whole house units also use refrigerant. They are connected to the house’s HVAC system (or central air conditioning). Since it caters to large spaces, it pulls humid air through a duct network.
As the air enters through the return duct, the water is absorbed by the refrigerant and is then processed for dehumidification in the same way as in compressor units.
Which Type of Dehumidifier Is Better?
Refrigerant dehumidifiers can only work at high temperatures (above 32°F / 20°C) as the environmental temperature needs to be higher than the cooling coil for the moisture to condensate.
On the other hand, desiccant dehumidifiers are highly effective in cold climates and compatible with high temperatures. They are also considerably quieter (because there is no fan compressor), smaller, and more portable than refrigerant dehumidifiers.
However, compressor dehumidifiers can save up to 50% more electricity than desiccant systems in hot weather. Therefore, refrigerant dehumidifiers are an ideal option for warm climates.
Whole-house dehumidifiers should be preferred in highly humid areas, especially in homes with a basement or storage area.
Best Dehumidifiers
Here are the top dehumidifiers from each of the three categories:
hOmeLabs Energy Star Compressor Dehumidifier – Best Refrigerant Dehumidifier
The hOmeLabs Energy Star is a compressor dehumidifier known for its efficiency and extensive coverage of 4500 sq. ft.
The unit is designed for a continuous operation enabled by a hose outlet. Attaching a 5/5″ garden hose to the slot allows collected water to be drained continuously, and you can enjoy uninterrupted operation.
Alternatively, if you decide not to use a drainage hose, the system automatically shuts off to prevent potential water damage to the dehumidifier components.
Its remarkable capacity to extract and hold 50 pints of water in 24 hours of operation is owed to the large 1.6-gallon water tank. Depending on personal comfort, users can accelerate or slow down dehumidification by setting the fan speed. For the best user experience, this model features varying fan speeds (normal air CFM 165 to high air CFM 188).
This unit has versatile and easy controls. For example, you can set the relative humidity to your desired level and set a timer that automatically switches the unit off after the selected hours of operation.
The compact and classy design of this dehumidifier makes for an excellent addition to a room’s aesthetics. Considering all its features, hOmeLabs Energy Star is one of the best compressor dehumidifiers you can go for.
Afloia Basement Dehumidifier X3 – Best Desiccant Dehumidifier
This dehumidifier by Afloia is considered one of the best desiccant dehumidifiers.
It runs efficiently at temperatures as low as 23°F (-5°C) and can extract 7L moisture daily. The water reservoir is at the front of the unit and is easy to detach. Alternatively, you can use the drain hose for continuous drainage of all the water collected from the air in your home.
It also comes with a carry handle that makes it easy to carry.
This device can be considered a combo unit as it comes with an filter that helps purifies the air, removing large particulate contaminants, including dust and debris. Besides that, it comes with a clothes dryer function! Simply press the button and hold some clothes above the unit to dry them quickly and quietly.
Another best thing about this Afloia dehumidifier is its versatile, touch-button controls. For example, the user can set a timer for 2, 4, or 8 hours for the system’s operation time.
All-in-all, the Afloia basement dehumidifier is your best bet if you’re looking for a desiccant dehumidifier.
Honeywell 50 Pint Energy Star Dehumidifier – Best Whole-House Dehumidifier
When speaking of modern-age dehumidifiers that offer premium quality and incorporate advanced technology for a great user experience, Honeywell 50 Pint Energy Star Dehumidifier is the one to look for.
This is a whole house dehumidifier designed for medium to large-sized rooms, cellars, storage areas, and basements measuring up to 3500 sq. ft. Its water reservoir has a large capacity, making it capable of removing and holding up to 50 pints of moisture in a continuous 24-hours operation.
To enable easy drainage and cleaning, this model comes with a detachable water tank that can conveniently be removed using a comfort-grip handle. In addition, the reservoir design has tank guards that ensure no water is spilled while emptying the tank.
This whole-house dehumidifier has an air filter that removes large airborne particles, dust, and debris from the air before passing it to the dehumidification system. This protects the mechanical parts and coils from dirt buildup. The filter is durable and does not need frequent replacements. A ‘Filter Clean’ alert in the unit lights up whenever the filter needs cleaning, and you can easily detach it, rinse and then reuse it.
What are the Effects of Low Refrigerant in a Dehumidifier?
Even though refrigerants are sealed inside the unit, they may leak. For a unit to work correctly, it needs to have a specific amount of compatible refrigerant.
Low refrigerant in a dehumidifier can have the following effects on the system components and dehumidification:
- Ineffective Dehumidification: If the refrigerant is low, the dehumidifier cannot extract an adequate amount of moisture from the air. This will result in inefficient dehumidification.
- Overheating: When the dehumidifier fails to achieve and maintain the set relative humidity, the system can begin to overwork, which leads to overheating.
- Damage to Mechanical Components: If the overheating is not promptly addressed, it may lead to potentially permanent damage to the fan motor, compressor, and other essential components of the dehumidifier.
- High Electricity Bill: Low refrigerant and consequent damage to the dehumidifier consumes more energy and can significantly increase your electricity bills.
Are Refrigerants Not Used Anymore?
Many refrigerants, especially CFCs and HCFCs, were developed because they were more effective than other options. However, many governments have banned their production over time due to their debilitating effects on the ozone layer.
This is particularly relevant to R-22, a component found in CFCs and HCFCs and is the primary factor responsible for the high ozone depletion potential of both these refrigerants. For the past few years, R-22 production has been banned across the United States, and therefore, Freon and HCFCs are no longer used in new appliances.
In place of Freon, its highly efficient and cost-effective alternative, R-104A, is preferred by manufacturers because of its zero ODP. It is commonly known as Puron, EcoFlor, Forane, Genetron, and Suva.
Why and When Did They Stop Using Freon In Dehumidifiers?
Freon was used in dehumidifiers up until 2009. However, due to its hazardous effects on the ozone layer, the use of Freon was discouraged and reduced afterward, and then in January 2020, EPA entirely banned Freon (R-22) production in the US.
Now, another refrigerant called Puron (R410A) is used as an alternative to Freon. It does not emit any ozone-depleting chemicals and is, therefore, safe for the environment.
Besides this, Puron is more energy efficient than Freon (costs less on electricity bill); thus, more manufacturers are drawn towards using it.
What Does Freon Smell Like?
Freon’s smell is similar to chloroform’s, i.e., a sweet-smelling ether-like smell. However, Freon is odorless when inside an appliance, and can only be smelled in case of a gas leak.
What are the Hazardous Implications of Refrigerants?
Here are some of the hazardous effects of refrigerants:
- They are flammable and need to be managed carefully when in an appliance. Exposure to a high concentration can cause burns on the skin and other physical damage.
- Asphyxia (oxygen deprivation) and dyspnea (shortness of breath)
- Severe pain in the sinuses
- Vomiting and diarrhea
- Heartburn
- Arrhythmias (irregular heartbeat)
- Rectal bleeding
Although refrigerants are sealed in appliances, cracks in the unit can cause a gas leak. Therefore, when using ACs, dehumidifiers, and other refrigerant systems, be wary of signs of a gas leak. Usually, symptoms include the poor working of appliances, hissing sounds from the unit, and significantly higher electricity bills. You may also experience the distinct sweet smell of the gas.
