In general, dehumidifiers work best in warm and humid environments. As the air temperature decreases, the air loses its ability to hold water vapor. Thus, there’s less moisture to remove in cold spaces. However, you can still reduce humidity at low temperatures using a desiccant dehumidifier.
Desiccant dehumidifiers come in a wide variety of sizes with many different applications. Compared to the more common compressor dehumidifiers, the desiccant type is suitable for spaces with lower temperatures and humidity levels. You have disposable moisture absorbers or rechargeable units for tiny spaces, rotor-based models for small to medium rooms, and even high-capacity commercial units for heavy-duty use.
Whatever you need a dehumidifier for, you can find a desiccant unit suitable for the purpose. Before you purchase any product, it’s essential to first consider the dehumidifier capacity necessary for the room size and condition. You must also look at each of the features, especially when buying a commercial unit. To help you, we’ve put together a guide consisting of everything you need to know about desiccant dehumidifiers. Below, we’ve also listed five different types of desiccant dehumidifiers perfect for various applications.
Top 5 Best Desiccant Dehumidifiers
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Desiccant Dehumidifier Reviews
Moisture Removal Capacity: 13 pints per day
Tank Capacity: 3.8 pints
Dimensions: 10.59 x 6.85 x 17.52 inches
Power Draw: 280~470W
The Ivation brand offers a variety of residential dehumidifiers, including this 13-pint desiccant unit. Unlike other Ivation dehumidifiers, this unit removes 13 pints of moisture in temperatures from 33°F to 104°F. It provides quick and efficient dehumidification in small spaces up to 270 square feet.
This portable desiccant dehumidifier features an LCD display and convenient touch buttons that allow you to adjust the humidity level from 35% to 85% in 5% increments. The unit will maintain your desired humidity automatically, or you can set it to operate continuously.
You can also set the timer to auto start or stop operation after one to 12 hours. The built-in safety features include the auto-stop function that prevents damage by automatically shutting off the unit during a threat of tilt or water overflow. In case of a power outage, the auto-restart will resume operation in your last settings once the power returns.
This Ivation dehumidifier also features Sleep mode with low fan speed and a dimmable screen. Additionally, you can change the fan speed and adjust the air vents as needed. The unit also comes with a washable air filter and a 3.8-pint water tank. If you don’t want to empty the tank manually, simply attach the included drain hose to the outlet to divert the water to a low-level drain or sink.
Overall, if you need a versatile dehumidifier you can use in any small room, you can’t go wrong with the Ivation 13-pint desiccant unit. If you need a bigger capacity and coverage, consider this 19-pint model. However, one downside is that desiccant dehumidifiers typically cost more and consume more power than compressor dehumidifiers of similar size.
Moisture Absorption Capacity: 6~8 oz.
Dimensions: 5.5 x 2.5 x 5.5 inches
For tiny rooms or storage spaces with less severe humidity issues, a wireless desiccant dehumidifier may be more than enough. The Eva-Dry E-500 renewable dehumidifier doesn’t need electricity or batteries to start working, making it suitable for many different purposes. It contains silica gel beads that are completely safe, non-toxic, and environment-friendly.
Through the indicator window on the front, you can see the silica gel change color from orange to green once they have reached the capacity of 6 to 8 ounces. This usually happens within 30 to 60 days or after a few weeks. To recharge, just plug the unit into a power outlet for 12 hours to dry out the moisture. The silica gel can be renewed repeatedly for up to ten years, guaranteed with a five-year warranty.
As the name suggests, the Eva-Dry E-500 can cover an area of 500 cubic feet (not square feet!). Remember that this type of mini dehumidifier does not have a significant impact on the humidity level in a full-size room. Its main purpose is to keep moisture down in small, enclosed spaces such as a closet, car, or boat cabin without actively using electricity. It can even fit in kitchen pantries, safes, and storage cabinets. The smaller Eva-Dry E-333 Wireless Dehumidifier (also available in twin packs) is also great even for gym bags.
Moisture Extraction Capacity: 18 ounces
Dimensions: 4.13 x 6.69 x 5.63 inches
Compared to most other dehumidifiers, DampRid moisture absorbers don’t need electricity at any point. It uses calcium chloride crystals that absorb moisture as soon as they are exposed to the air. The crystals harden as they collect moisture, then they dissolve into a liquid. This can take a few weeks up to months. Once all the crystals are liquefied, simply discard and replace the product.
DampRid comes in a small container you can easily take with you even when traveling in an RV or camper. Different sizes are also made for closets, bathrooms, laundry rooms, and bedrooms. With added fragrance beads or activated charcoal, it can also eliminate odors in any small, enclosed space. Moisture absorbers like DampRid are incredibly easy to use. Just peel off the cover and place the container where you need it.
However, not everyone can benefit from this type of dehumidifier. They have a limited capacity of around 10 to 14 ounces for the small tubs or hanging packets. They are also only effective in tiny spaces typically around 100 to 200 square feet, or up to 1,000 square feet for the Hi-Capacity according to DampRid. In rooms with serious humidity issues, you may be better off with an electric dehumidifier.
Moisture Removal Capacity:25 pints per day
Dimensions: 7.87 x 11.81 x 7.87 inches
Power Draw: ~550W
If you want a professional-grade dehumidifier for residential or commercial use, then Ecor Pro is for you. This line of desiccant dehumidifiers is built specifically for harsh environments present in sailboats and crawlspaces. One of the smaller models is the EPD50-PRO which can remove up to 25 pints of moisture in spaces up to 1,000 square feet, or equivalent to 50 pints per day in compressor-based dehumidifiers.
This desiccant dehumidifier operates efficiently from -4°F to 104°F with a maximum airflow of 73 CFM. Unlike the dehumidifiers we featured above, this desiccant unit does not produce any liquid. Instead, it has to be ducted to and from the outside to release the warm, moist air from the room to the outside.
Using the four-hole system, this unit has two separate air streams (process and reactivation) and two internal fans. The second fan allows for pressure-neutral drying wherein only the processed, dry air enters the room while all the collected moisture is vented outside. This makes the EPD50-PRO suitable for low-temperature operation.
Ecor Pro is built with 316 marine-grade stainless steel that is highly resistant to salt air and other harsh conditions. It’s recommended for sea vessels, boats, yachts, and other marine environments, as well as commercial spaces with extreme temperatures and crawl spaces in homes. The unit self-regulates to ensure optimum efficiency at any temperature and humidity level. The small casing can be mounted in any orientation, on the floor, wall, or ceiling. It also comes with a dust filter that can easily be shaken clean or replaced.
This compact and portable dehumidifier is easy to install by one person. Additionally, there is an option to connect the Ecor Pro EPHUM220 humidistat for remote operation and control. However, note that the costs of buying and operating this dehumidifier require a good budget.
Moisture Removal Capacity: 118 pints per day
Dimensions: 33.13 x 21.14 x 20.25 inches
Dri-Eaz is a popular brand of portable solutions for water damage restoration and dehumidification. While they are known for compressor dehumidifiers, they also offer desiccant units such as the Dritec 4000i dehumidifier. Unlike other larger refrigerant-based units from Dri-Eaz, the Dritec operates efficiently in subzero temperatures and lowers humidity down to 0% RH.
This high-efficiency desiccant dehumidifier is ideal for hard-to-dry materials like hardwood floors, plaster, bricks, and concrete. This portable industrial unit removes up to 118 pints per day under AHAM conditions of 80°F and 60% humidity, with process airflow at 395 CFM and reactivation airflow at 65 CFM.
The digital display shows real-time temperature and relative humidity readings for the inlet and outlet ducts, the average amount of moisture removed, and the amperage currently used. You set the humidity from 5% to 60% with the onboard humidistat, and reset the hob hours on the panel. It also includes the four options for display language: English, French, German, and Spanish.
Similar to the refrigerant units from Dri-Eaz, the Dritec 4000i features two large semi-pneumatic wheels and a foldable handle on top for easy storage and transport. It can operate vertically or horizontally for flexible setup in low-clearance areas like crawl spaces. It also offers multiple ducting options based on your needs. The unit is equipped with a Positive Thermal Coefficient (PTC) heater for better efficiency, safety, and longer life.
This portable unit has an onboard compartment for accessories. The rugged steel case is guaranteed with a seven-year warranty, two years for the desiccant rotor, and one year for other parts and labor. For even more choices, check our article for the best industrial desiccant dehumidifiers.
Types of Desiccant Dehumidifiers
The most important component of a desiccant dehumidifier is the desiccant material itself. It is a kind of hygroscopic substance that extracts moisture from the air through a process of absorption or adsorption. These chemicals typically consist of crystal-like beads of silica gel or calcium chloride, depending on the type of desiccant dehumidifier. They come in a wide variety of sizes, some can be disposable or rechargeable, while industrial units can provide huge performance without ever producing gallons upon gallons of condensate.
Disposable Desiccant Dehumidifiers
Also called a moisture absorber, this type of desiccant dehumidifier is made of hygroscopic chemicals, mainly calcium chloride, sodium chloride, and potassium chloride, which absorb moisture from the air until they dissolve into the liquid. It is usually small and cheap with a very low moisture extraction capacity. It doesn’t need to be plugged in to start removing moisture from the air. Moisture absorbers are ideal for closets, safes, boat cabins, cars, or tiny rooms with little moisture content. As the name implies, they must be disposed of after one use.
Rechargeable Desiccant Dehumidifiers
A renewable desiccant dehumidifier works using silica gel beads that adsorb moisture from the air. Similar to the disposable type, it is small in size, capacity, and price. It also doesn’t need electricity to start working, making it ideal for wardrobes, kitchen pantries, and gun safes without power sockets. Although, note that it does need to be plugged in to recharge after four to six weeks to dry out the moisture. You can then reuse the silica gels repeatedly for up to five years.
Full-Size Desiccant Dehumidifier
A full-size consumer-grade desiccant dehumidifier is similar in size and appearance as the standard compressor dehumidifier commonly used at home. It also uses silica gel beads impregnated into a wheel that continuously rotates inside the machine. Like the compressor type, this residential desiccant dehumidifier produces condensate in a tank, although usually at a slower pace.
Commercial Desiccant Dehumidifier
These high-powered desiccant dehumidifiers are suitable for use in commercial spaces with low temperatures and low humidity levels. They are capable of strictly maintaining humidity in sub zero temperatures as well as drying materials that are difficult to dry. They come in a variety of sizes, from portable units that can be moved and transported to construction sites or water restoration jobs, to a full system installed with the central HVAC. They use ducting and do not produce condensate.
How Does A Desiccant Dehumidifier Work?
Different types of desiccant dehumidifiers work in different ways, but the main process they use to extract moisture from the air is either absorption or adsorption. Absorption occurs when the desiccant substance dissolves as it takes moisture from the air, as is the case with moisture absorbers. The desiccant, such as calcium chloride or potassium chloride, mixes with the moisture to form a liquid that collects in the container of the moisture absorbers. We also talk about this process in more detail in this article about DampRid moisture absorbers.
On the other hand, adsorption occurs on the surface of the desiccant, typically silica gel. As the air comes into contact with the desiccant, the water molecules cling to the surface of the silica gel beads until they have reached the maximum capacity they can hold. Rechargeable dehumidifiers only contain a small amount of silica gel with a limited capacity of around 4 to 6 ounces. Once it has reached this capacity, you need to heat it up to “desorb” the moisture and thus renew the silica gel.
Full-size residential and commercial desiccant dehumidifiers have similar processes except for the method they release the collected moisture. Both use silica gel infused into a corrugated wheel. A fan pulls air into the system and a filter protects the internal components from impurities in the air. The air passes through a portion of the desiccant rotor and here the moisture is adsorbed, then the dryer air is heated and pushed out through a fan. The saturated part of the rotor is also heated so that moisture desorbs and forms water droplets.
With industrial desiccant dehumidifiers, you need to take note of the two separate air streams: the process air and reactivation air. The process air, or the humid air from the room, is drawn into the dehumidifier through fans, then it passes through the process zone of the desiccant wheel. This section makes up at least half of the rotor. The silica gel then adsorbs moisture from the air.
The heater warms the reactivation air as it enters, producing hot, dry air. When the reactivation air passes through the wheel, moisture is transferred from the desiccant to the dry air, thus “reactivating” the desiccant. The resulting humid air from the reactivation zone is released to the outside through ducts. For further details on this process, check our article for the best commercial desiccant dehumidifiers.
Residential Vs. Commercial Desiccant Dehumidifiers
Residential and commercial desiccant dehumidifiers start the dehumidification process the same way but have different products. They consist mostly of the same part, except that those in commercial units are built for tougher jobs, and are physically bigger and heavier. They both feature a desiccant wheel with silica gel as well as a heater to warm the air.
The main difference between the two is what they do with the warm, humid air that has already passed through the saturated desiccant. In consumer-grade dehumidifiers, this air goes straight to a condenser, cooling down the warm, moist air until water droplets form and drip into the collection bucket. Similar to compressor dehumidifiers, you can empty and replace this bucket easily, or use a drain hose for continuous drainage via gravity. It’s important to note that the air passes through the heater before the condenser, so even if the air that initially enters the unit is cool, it has already been warmed up and will form condensate easier.
Meanwhile, commercial units do not exhaust the excess moisture in condensate form. Instead, the warm, humid air that passes the reactivation zone of the desiccant rotor is vented right out of the room or building through ductwork. Since there is no condensate that forms, commercial units continue to dehumidify the air at even lower temperatures and humidity levels than residential units.
Features to consider while choosing a desiccant dehumidifier
Dehumidifier capacity refers to the total amount of moisture it can remove within 24 hours of continuous operation. With a regular compressor dehumidifier, this is typically measured in pints per day or PPD, but with residential desiccant dehumidifiers, this isn’t usually a big deal. Mini desiccant units have a very small capacity ranging from 4 to 10 ounces for rechargeable units and 10 to 14 ounces for moisture absorbers. Also, note that they collect this total amount after a few weeks up to months and not daily. For industrial desiccant dehumidifiers, a higher capacity means a larger desiccant wheel, taking up more space and consuming more power.
Desiccant dehumidifiers generally come in a compact build suitable for small areas. The only type that requires draining is the rotor-based residential unit. It comes with a tank or a drain hose similar to compressor dehumidifiers except smaller in capacity. Since they are smaller, they also don’t need a pump for automatic drainage. As for other desiccant dehumidifiers, they do not require a reservoir tank or drain hose for the collected moisture. However, commercial desiccant models do need to be ducted outside or through multiple rooms to distribute dry air and exhaust the warm, humid air.
Operating Temperature Range
The range of temperatures it can operate in is a huge advantage of a desiccant dehumidifier over other types. However, it can still vary greatly depending on the model and capacity. On average, a residential desiccant dehumidifier should be able to function in temperatures as low as 33°F and as high as 100°F. Although, remember that cold air may not contain a lot of moisture in the first place. Commercial units are built with high-performance components that enable them to control humidity down to 0% RH or below 0°F conditions.
Dehumidifier Features and Ease of Use
As previously mentioned, desiccant dehumidifiers come in a wide variety of sizes and features. Usually, the smaller the capacity, the more limited features a unit has. On the upside, this makes the dehumidifier simpler and easier to use for anyone in any area it’s needed. Mini desiccant dehumidifiers don’t even require electricity to start working, you simply put them inside the space you want to dehumidify. Full-size residential desiccant dehumidifiers come with a lot more features similar to regular compressor dehumidifiers, including a humidistat and timer. They also feature standard functions such as auto shut-off and auto restart and come with an air filter for improved air quality. As expected, commercial units are packed with more advanced features.
Warranties and Replacement Parts
Whenever you buy any appliance, it’s important to look for a good warranty policy. A longer warranty period gives you greater trust and confidence in the quality and reliability of the product. Most dehumidifier manufacturers offer a standard one-year warranty for all parts and labor. Within this period, you should be able to get replacement parts or a refund from the manufacturer, depending on the warranty guidelines. While a longer coverage is usually the preferred choice, a warranty policy from a well-known brand is more reliable than the same period from a lesser-known brand, but it can vary from case to case.
Desiccant Vs. Compressor-Based Dehumidifiers
When talking about residential dehumidifiers, compressor-based units are usually the first thing that comes to mind. They are widely available in the market in a vast range of sizes with many different features. However, they aren’t always the best choice for every application. A desiccant model may not be as common but it has its own uses and benefits that you can’t get from a refrigerant dehumidifier. Before you choose any unit, weigh the following pros and cons of using a desiccant dehumidifier, either for residential or commercial use.
Desiccant Dehumidifier Advantages
Operates at Lower Temperatures
The main difference between the two types of dehumidifiers is the processes of moisture removal. Compressor units use refrigerant coils to cool the moist air down to its dewpoint where the gaseous moisture condenses into water. This moisture is drained out or collected in an internal tank while the dryer air is released into the room. This method works best in a highly humid and warm environment.
When the air is already cold, the coils cannot cool it down further. Because of this, standard compressor or refrigerant dehumidifiers can only operate in temperatures as low as 41F while their efficiency starts to decrease at 65F. In low temperatures, the moisture may even form frost on the coils. Frost blocks the airflow and may damage the coils and other internal components. To avoid frost buildup, most compressor dehumidifiers feature auto-defrost to automatically stop operation and melt the ice.
On the other hand, a desiccant dehumidifier extracts moisture from the humid air without the need to cool it down first. Thus, it can continue to operate at lower temperatures. With residential dehumidifiers that collect water, there are fewer risks of frost buildup because the system heats up both the desiccant and the air itself before it passes through a condenser. Commercial desiccant dehumidifiers do not form condensate and vent the humid air right out. That’s why they’re the perfect choice for industrial applications in extremely cold environments.
Additionally, the desiccant dehumidification process does not limit its capacity in lower temperatures. Since a desiccant dehumidifier can handle extremely low temperatures, it retains the same efficiency even in extreme environments. It may remove higher amounts of moisture in a 90°F environment as opposed to 60°F, simply because a higher ambient temperature means the air can hold more water vapor.
Operates at Lower Humidity Levels
Residential desiccant dehumidifiers are not too different from their compressor-based counterparts. As we discussed above, they have most of the same features on the outside so the only real difference is the main process they employ inside the machine. Both have a digital humidistat to control and maintain the humidity down to 30% RH. Anything below this level can be harmful to humans.
Commercial refrigerant dehumidifiers, on the other hand, typically use low-grain refrigerant or other advanced technologies to enable low-temperature operation in water-damaged areas and other spaces where you need powerful moisture removal. However, there is still a limit to their dehumidifying abilities in conditions with low temperatures and low humidity levels. They do work quickly and effectively in warm climates down to 30% humidity, which makes them suitable for commercial areas frequently populated by people.
Also, compressor dehumidifiers are not ideal for certain industrial spaces that need extremely low humidity. This is because they only extract moisture by cooling the air down to the temperature where the water vapor condenses. Thus, dry (and cold) air needs to be cooled even further to reach that point.
Industrial applications such as food production, packaging, and storage, strictly require low levels of temperature and humidity to preserve the products. In this case, a commercial desiccant dehumidifier is especially useful in maintaining low humidity levels in sub-zero temperatures. Regardless of the ambient humidity, the silica gel desiccant will extract all the moisture it can get from the air until it is fully saturated.
A desiccant dehumidifier is usually light and compact and easy to use. In fact, the only maintenance you’ll ever need to do for mini units is to dispose of, refill, or recharge them. Desiccant dehumidifiers with tanks require similar maintenance to refrigerant dehumidifiers, but the good thing is the former has fewer components that can malfunction. Also, a compressor-based dehumidifier is composed of heavy metal parts, such as the evaporator and condenser coils. Meanwhile, the main bulk of a desiccant dehumidifier is in the desiccant wheel. Since commercial-grade desiccant dehumidifiers don’t produce condensate at any stage of their process, they don’t need a built-in reservoir or a hose or pump for drainage.
Desiccant Dehumidifier Disadvantages
Moisture absorbers are available in 10 to 14 ounces capacity for the small tubs or hanging packets. This is the total amount of moisture it can remove over a few weeks of use. Meanwhile, the Hi-Capacity bucket has a 4-pound capacity that can last up to six months. Full-size desiccant units like the Ivation range from 10 to 20 pints. In comparison, refrigerant dehumidifiers can remove 20 to 50 pints of moisture per day.
Because of their small physical size and moisture removal capacity, residential desiccant dehumidifiers can only be used in small spaces (typically around 100 to 200 square feet). Most of the disposable and rechargeable types are only suitable for tiny rooms or storage spaces and will make little to no impact on humidity levels in a full-sized room. If you need a capacity from 50 pints and above, then you should look for a portable commercial desiccant dehumidifier like the Ecor Pro.
Looking at the value for your money in terms of the maximum amount of moisture your dehumidifier can remove, then a desiccant dehumidifier is not better than a similar compressor unit. A typical rechargeable desiccant is around 20 times cheaper than the average 50-pint compressor-based dehumidifier. However, the former has a total capacity of about 0.5 pint every few weeks, which is 100 times smaller than the daily 50 pints. Therefore, you get more value per dollar invested in a compressor dehumidifier. Full-size desiccant units, on the other hand, are usually more expensive than similar size compressor dehumidifiers. For example, the Ivation 13-pint desiccant costs a few more dollars than the Ivation 14.7-pint compressor unit.
Higher electricity cost
Aside from costing more upon purchase, desiccant dehumidifiers also require more electricity to operate. For instance, the 13-pint Ivation desiccant consumes 280 up to 470 Watts of power, while the 14.7-pint compressor unit consumes only 200 to 220 Watts. Standard 30-pint compressor dehumidifiers usually require 300 to 500 Watts, 50-pint units require 500 to 700 Watts, and so on.
Proper Usage and Maintenance of Desiccant Dehumidifiers
Dehumidifiers are each built and designed for various purposes and may require different forms of maintenance, but there are some common practices you must observe to ensure the maximum efficiency of the product for a long time.
Starting from installation, follow the manufacturer’s instructions provided in the manual. Take note of the operating temperature range for safe operation. Residential desiccant dehumidifiers are simple to use and require little maintenance. However, commercial units are more complicated. For your safety, it’s best to let a professional do the installation job. Although, portable models like the Dri-Eaz Dritec are simple enough to operate from site to site.
Before performing any maintenance, make sure the unit is turned off and unplugged. If your unit has filters or a tank, it is important to regularly inspect them for dust or dirt. Empty the water as soon as possible, clean the tank, and wash or replace the filter as needed. The desiccant rotor also needs cleaning depending on your unit’s specific requirements.
These are only some basic guidelines you can follow. Whatever the case, make sure you know how to use and maintain your desiccant dehumidifier properly. A good desiccant dehumidifier can work better than any other type of dehumidifier if used for the right purpose and place. If you’re looking for a residential dehumidifier for low-temperature operation, we also list the best units for this purpose in the best low-temperature dehumidifier article.