How does desiccant dehumidification work

When it comes to reducing the humidity from air in your home, one of the best ways to do so is by using a desiccant dehumidifier. It works by drawing moisture from the air and replacing it with purified air. This process helps to remove harmful particles, dust mites, and other allergens from the air. But what is the process:

How does Desiccant dehumidification Work, it use an absorbent material, such as silica gel, to remove moisture from the air. The material is then heated so that the moisture drips into the water tank. This process is also known as adsorption & drying.

How does desiccant dehumidification work

 In this blog post, we’ll take a closer look at the science behind it and discuss some of its benefits for your home’s air quality. 

What is a Desiccant Dehumidifier?

A desiccant dehumidifier is a revolutionary air-drying device that utilizes a unique and efficient process to remove humidity from the air. Unlike traditional refrigerant-based dehumidifiers, desiccant dehumidifiers rely on an absorbent material called a “desiccant” to capture moisture particles. This desiccant wheel rotates slowly over a period of time, allowing it to take in larger amounts of water vapor than refrigerants.

To providing superior performance, these devices are also much quieter, operate at very low temperatures, and require less electricity making them significantly more energy efficient and environmentally friendly. With their exceptional capacity for absorbing large amounts of moisture without requiring high levels of energy, desiccant dehumidifiers make an excellent choice for any home or office.

What is Adsorption?

Desiccant adsorption is a process of humid air being attracted to, and held on the surface of a desiccant (adsorbent), rather than absorbing it into the desiccant. Think of Tetris- where blocks of four are adsorbed onto the surface below. This same concept is used in desiccant dehumidifiers with silica gel, which acts as an effective adsorbent at very low temperatures.

You may be familiar with activated carbon, which is also commonly used as an adsorbent in air filters to capture odors and gases. And small packets filled with silica gel that you often find in medicine bottles serve to absorb any moisture that accumulates inside the bottle.

How does desiccant dehumidification work:

There are four modes of operation that keep a desiccant dehumidifier working. The main steps include:

  • Single fan – Built in internal heat recovery
  • Dual fan – External heat recovery option available
  • Dual fan – Built-in internal heat recovery
  • Dual rotor – double inline heat recovery

Different types of desiccant dehumidifiers

Single fan – Built in internal heat recovery:

Built-in internal heat recovery is a feature of desiccant dehumidifiers that makes them incredibly attractive for those looking to reduce their operating costs and environmental impact. By passing the reactivation air through a small section of the rotor, commonly referred to as the purge sector (heat recovery sector), this preheats the reactivation air and allows for optimal heat recovery.

Single fan - Built in internal heat recovery

This helps to significantly reduce energy consumption, allowing for an efficient operation with minimal power use, whilst simultaneously reducing the amount of heat added in to the process sector. The result is lower running costs as well as reduced environmental impact.

Due to the low level of adsorption at high surface temperatures, only a small amount of moisture is absorbed back into the rotor through this sector. This ensures that the desiccant dehumidifier is able to maintain consistent humidity levels and offer a reliable solution for any environment. The built-in internal heat recovery feature of desiccant dehumidifiers makes them an ideal choice for anyone looking to save money, reduce their environmental impact and ensure a consistently clean and dry atmosphere.

Dual fan – External heat recovery option available:

The dual fan – external heat recovery option available is a highly efficient, energy saving system for dehumidifying and cooling the air. This mode of operation uses two fans to circulate the air around a desiccant rotor wheel which holds an extremely high concentration of silica gel.

As humid process air passes through the wheel, adsorption takes place and moisture is extracted from the air. To continue this drying process, a separate counter flow airstream is used to reject moisture from the rotor, following reactivation with heated air up to 140°Cdb.

Dual fan - External heat recovery option available

By using an external cross flow heat exchanger, valuable energy is recovered from this reactivation airflow which would otherwise be lost outside. The hot, humid air then exits the desiccant dehumidifier, while a cooler, drier air is supplied inside. This system provides an efficient and cost-effective solution for controlling moisture levels in commercial and industrial environments which need to be kept at optimal humidity levels.

It can also be used in applications where the return of collected condensate to the rotor is not acceptable, such as humid climates with no moisture return. With this dual fan – external heat recovery system, energy savings are maximized and indoor air quality is improved.

Just imagine a space that has perfect temperatures and humidity levels all year round! That’s what you get when you invest in the dual fan – external heat recovery option available from MDC300 to MDC3000 range of desiccant dehumidifiers.

You get the maximum energy savings and air quality control you need to keep your indoor environment at its best! So, what are you waiting for? Make the smart choice now and enjoy all the benefits of a perfectly balanced climate in your home or office.

Dual fan – Built in internal heat recovery:

The dual fan with built in internal heat recovery makes this type of desiccant dehumidifier an incredibly efficient and reliable solution for removing moisture from the air. This mode of operation involves two separate centrifugal fans, one for process air intake and another for reactivation air exhaust/supply.

The reactivation airflow is first passed through a small section of the rotor commonly referred to as the purge sector (heat recovery sector). This preheats the reactivation air, significantly reducing energy consumption whilst reducing the heat gain in the process sector. A high temperature low relative humidity air is then used to break the molecular bond between water vapor and silica gel, resulting in a warm but dry airflow that is exhausted outside.

Dual fan - Built in internal heat recovery

Moreover, the dual fan configuration allows for continuous operation without interruption to switch fans or shut off the unit. This means that no time is wasted between desiccant cycles and the unit can run as long as necessary to achieve desired humidity levels. Additionally, this design also prevents any mixing of process air and reactivation airflows due to a special holding frame from both sides of the desiccant wheel.

Finally, the absence of condensation during dehumidification ensures that there is no need for connection to a drainage system – making it an incredibly convenient solution for many applications! All these features make this type of dehumidifier an attractive choice for anyone looking for efficient and reliable moisture removal.

Dual rotor – double inline heat recovery:

The dual rotor – double inline heat recovery system is one of the most efficient solutions to dehumidifying large volumes of air. By using a combination of return and fresh air streams, it reduces the latent load on the primary rotor, resulting in faster room/process pull down times and extreme low dewpoints.

Dual fan - Built in internal heat recovery

Furthermore, this type of system enables users to decarbonise their systems through renewable sources such as wind power, tidal energy, or solar PV electricity. Thanks to its dual-rotor design, this innovative system offers an impressive level of energy efficiency with minimal reactivation power required.

Not only does it provide a more environmentally sustainable option but also a cost-effective one as it helps save on operational costs. With an easy installation process, this advanced dehumidifying system is an ideal choice for any space that requires precise and reliable humidity control.

Different types of desiccant dehumidifiers:

There are four type of desiccant dehumidifiers that are used for air dehumidification in commercial and industrial settings.

  1. Commercial and industrial rotary desiccant dehumidifiers
  2. Rechargeable desiccant dehumidifiers
  3. Disposable desiccant dehumidifiers
  4. Rotary desiccant dehumidifiers

Commercial and industrial rotary desiccant dehumidifiers:

Commercial and industrial rotary desiccant dehumidifiers are incredibly efficient and reliable machines that are used in a wide variety of settings to ensure the air is kept dry. They are renowned for their ability to quickly and effectively reduce humidity levels with minimal power consumption.

Rotary desiccant dehumidifiers

Desiccant dehumidifiers use silica gel to absorb moisture from the air, preventing it from reaching uncomfortable or damaging levels. This highly effective system works by filtering humid air through a drying chamber filled with silica gel beads which absorb the water vapor, before passing clean, dry air back into the environment.

Unlike traditional refrigerant-based dehumidifying systems, commercial and industrial desiccant dehumidifiers do not require cooling coils or condensers to extract moisture from the air. Instead, they employ a fan-driven system with two distinct chambers; one for drying and one for reactivating the silica gel beads.

Rechargeable desiccant dehumidifiers:

Rechargeable desiccant dehumidifiers are an incredibly efficient and reliable form of air dehumidification that is perfect for both residential and commercial spaces. Unlike other traditional forms of dehumidifying, rechargeable desiccant dehumidifiers work using a silica gel-based drying system which requires no additional cooling coils or condensers. Instead, they rely on the heat generated by the fan to reactivate the gel beads so that they can continue absorbing moisture from the air – making them much more energy-efficient than their refrigerant counterparts.

The biggest advantage offered by rechargeable desiccant dehumidifiers is their convenience; once set up, there’s no need to continuously monitor your dehumidifier as the gel beads will reactivate themselves whenever they reach maximum capacity. Additionally, there’s no need to purchase additional silica gel or dispose of it when full – simply recharge it and you’re good to go!

No matter what type of space you’re looking to dehumidify, rechargeable desiccant dehumidifiers are an ideal choice. Not only do they provide highly efficient and cost-effective humidity control but also help to save on energy costs by consuming less power than their refrigerant-based counterparts. So if you’re looking for an easy and convenient way to keep your home or business comfortable and dry, rechargeable desiccant dehumidifiers are an excellent option.

Disposable desiccant dehumidifiers:

Disposable desiccant dehumidifiers are an easy and convenient way to reduce humidity in enclosed spaces such as closets, cabinets, or sealed bags. These tiny packs contain moisture-absorbing chemicals that can quickly reduce the amount of water vapor in the air. Unlike more expensive electronic dehumidifier models, disposable desiccant dehumidifiers don’t require any energy source – just open up the pack and place it wherever extra moisture needs to be absorbed.

Disposable desiccant dehumidifiers

When the pack has reached its saturation point, simply discard it and replace with a new one for ongoing protection from excess humidity. With their no-nonsense design, disposable desiccant dehumidifiers are a great choice for anyone looking for an economical and effective solution to humidity control problems.

They’re usually small enough to fit almost anywhere – making them perfect for those tight spots! So, if you’re looking for a way to keep your home or office dry and comfortable, consider using disposable desiccant dehumidifiers.

Rotary desiccant dehumidifiers

Rotary desiccant dehumidifiers are an incredibly efficient way of drying the air in any space. These self-contained, all-in-one units have a special wheel that is made from a desiccant material. This wheel sucks moisture out of the air as it passes through one side, and then reactivation air flows through a heating coil on the other side of the wheel to remove even more humidity.

The air is then cooled by a condenser coil which causes the moisture to condense out of the reactivation air and collect into a tank for disposal. Rotary desiccant dehumidifiers are popular because they are easy to use and transport – perfect for taking from room to room or job site to job site. Plus, they are extremely effective at removing unwanted humidity from any space!

Benefits of using a dehumidifier:

The top 10 benefits of using a dehumidifier are asfollowsw:

  1. Reduces allergens in the air: Dehumidifiers reduce mold and mildew by removing excess moisture from the air, which helps to reduce allergens like dust mites, pet dander, pollen, and other airborne particles that can aggravate allergies.
  2. Improves indoor air quality: Moisture levels are an important factor in air quality, and a dehumidifier can help to keep them at a comfortable level. This improves the smell and feel of your home’s air, making it easier to breathe.
  3. Prevents mold and mildew growth: High levels of humidity can cause mold and mildew to form on walls, ceilings, floors, furniture, clothing, and other items in your home. A dehumidifier can help reduce the humidity levels and prevent mold and mildew growth.
  4. Lowers energy costs: Reducing the humidity level in your home helps to make it easier for your air conditioner to cool down the space, which can lower your energy costs.
  5. Protects furniture and appliances: High levels of humidity can cause wooden furniture to warp, and electronic appliances can be damaged due to corrosion. A dehumidifier helps prevent this by keeping the moisture levels in check.
  6. Prevents condensation on windows: High levels of humidity can lead to condensation forming on your windows, which is not only unsightly but can also damage the wood or paint around the windows. A dehumidifier can help to reduce this problem.
  7. Prevents damage from water leaks: Leaks in the plumbing or roof can cause water damage in your home if left unchecked, but a dehumidifier can help to prevent this by removing excess moisture from the air and keeping it at a comfortable level.
  8. Reduces odors: Odors can become trapped in the air when there is too much moisture, but a dehumidifier can help to reduce these odors by removing the excess moisture.
  9. Prevents rust and corrosion: High levels of humidity can cause metals to corrode or rust, so keeping the humidity level at a comfortable level with a dehumidifier helps to prevent this from happening.
  10. Saves money by avoiding repairs: The cost of replacing damaged furniture and appliances can add up quickly, but a dehumidifier can help to reduce the possibility of these damages occurring in the first place, saving you money in the long run.


Desiccant dehumidification is an incredibly effective, efficient and convenient way to reduce humidity levels in any space. Whether you are looking for an energy-efficient rechargeable desiccant dehumidifier, a no-nonsense disposable option, or a highly portable rotary desiccant dehumidifier – there is something for everyone! Investing in one of these solutions can help provide instant relief from excess moisture and make your home or business more comfortable and dry. So why wait? Get the humidity under control with a reliable desiccant dehumidifier today your comfort will thank you!

Related F.A.Qs

What is the best dehumidifier method?

The best dehumidifier method will depend on the size of your space, the amount of moisture present and how often it needs to be removed. If you are looking for an energy-efficient solution with easy portability, then a rechargeable desiccant dehumidifier or a rotary desiccant dehumidifier would be ideal. Disposable desiccant packs are great for small spaces and short-term use.

How often should I replace my desiccant dehumidifier?

Rechargeable desiccant dehumidifiers do not need to be replaced as they can simply be recharged when needed. However, disposable desiccant packs should be replaced once they reach their maximum capacity and have stopped absorbing moisture. Rotary desiccant dehumidifiers should be replaced every 3-5 years, depending on the type of unit.

Are desiccant dehumidifiers noisy?

No! Desiccant dehumidifiers are incredibly quiet – perfect for those that want a low noise level in their home or office. Rechargeable units can reach noise levels as low as 25 decibels while rotary models can reach up to 40 decibels. Disposable packs are completely silent!

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